56 results on '"Hélène Angot"'
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2. Over a decade of atmospheric mercury monitoring at Amsterdam Island in the French Southern and Antarctic Lands
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Olivier Magand, Hélène Angot, Yann Bertrand, Jeroen E. Sonke, Laure Laffont, Solène Duperray, Léa Collignon, Damien Boulanger, and Aurélien Dommergue
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Science - Abstract
Abstract The Minamata Convention, a global and legally binding treaty that entered into force in 2017, aims to protect human health and the environment from harmful mercury (Hg) effects by reducing anthropogenic Hg emissions and environmental levels. The Conference of the Parties is to periodically evaluate the Convention’s effectiveness, starting in 2023, using existing monitoring data and observed trends. Monitoring atmospheric Hg levels has been proposed as a key indicator. However, data gaps exist, especially in the Southern Hemisphere. Here, we present over a decade of atmospheric Hg monitoring data at Amsterdam Island (37.80°S, 77.55°E), in the remote southern Indian Ocean. Datasets include gaseous elemental and oxidised Hg species ambient air concentrations from either active/continuous or passive/discrete acquisition methods, and annual total Hg wet deposition fluxes. These datasets are made available to the community to support policy-making and further scientific advancements.
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- 2023
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3. Measurements of aerosol microphysical and chemical properties in the central Arctic atmosphere during MOSAiC
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Benjamin Heutte, Nora Bergner, Ivo Beck, Hélène Angot, Lubna Dada, Lauriane L. J. Quéléver, Tiia Laurila, Matthew Boyer, Zoé Brasseur, Kaspar R. Daellenbach, Silvia Henning, Chongai Kuang, Markku Kulmala, Janne Lampilahti, Markus Lampimäki, Tuukka Petäjä, Matthew D. Shupe, Mikko Sipilä, Janek Uin, Tuija Jokinen, and Julia Schmale
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Science - Abstract
Abstract The Arctic environment is transforming rapidly due to climate change. Aerosols’ abundance and physicochemical characteristics play a crucial, yet uncertain, role in these changes due to their influence on the surface energy budget through direct interaction with solar radiation and indirectly via cloud formation. Importantly, Arctic aerosol properties are also changing in response to climate change. Despite their importance, year-round measurements of their characteristics are sparse in the Arctic and often confined to lower latitudes at Arctic land-based stations and/or short high-latitude summertime campaigns. Here, we present unique aerosol microphysics and chemical composition datasets collected during the year-long Multidisciplinary drifting Observatory for the Study of Arctic Climate (MOSAiC) expedition, in the central Arctic. These datasets, which include aerosol particle number concentrations, size distributions, cloud condensation nuclei concentrations, fluorescent aerosol concentrations and properties, and aerosol bulk chemical composition (black carbon, sulfate, nitrate, ammonium, chloride, and organics) will serve to improve our understanding of high-Arctic aerosol processes, with relevance towards improved modelling of the future Arctic (and global) climate.
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- 2023
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4. The Marginal Ice Zone as a dominant source region of atmospheric mercury during central Arctic summertime
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Fange Yue, Hélène Angot, Byron Blomquist, Julia Schmale, Clara J. M. Hoppe, Ruibo Lei, Matthew D. Shupe, Liyang Zhan, Jian Ren, Hailong Liu, Ivo Beck, Dean Howard, Tuija Jokinen, Tiia Laurila, Lauriane Quéléver, Matthew Boyer, Tuukka Petäjä, Stephen Archer, Ludovic Bariteau, Detlev Helmig, Jacques Hueber, Hans-Werner Jacobi, Kevin Posman, and Zhouqing Xie
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Science - Abstract
Abstract Atmospheric gaseous elemental mercury (GEM) concentrations in the Arctic exhibit a clear summertime maximum, while the origin of this peak is still a matter of debate in the community. Based on summertime observations during the Multidisciplinary drifting Observatory for the Study of Arctic Climate (MOSAiC) expedition and a modeling approach, we further investigate the sources of atmospheric Hg in the central Arctic. Simulations with a generalized additive model (GAM) show that long-range transport of anthropogenic and terrestrial Hg from lower latitudes is a minor contribution (~2%), and more than 50% of the explained GEM variability is caused by oceanic evasion. A potential source contribution function (PSCF) analysis further shows that oceanic evasion is not significant throughout the ice-covered central Arctic Ocean but mainly occurs in the Marginal Ice Zone (MIZ) due to the specific environmental conditions in that region. Our results suggest that this regional process could be the leading contributor to the observed summertime GEM maximum. In the context of rapid Arctic warming and the observed increase in width of the MIZ, oceanic Hg evasion may become more significant and strengthen the role of the central Arctic Ocean as a summertime source of atmospheric Hg.
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- 2023
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5. Widespread detection of chlorine oxyacids in the Arctic atmosphere
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Yee Jun Tham, Nina Sarnela, Siddharth Iyer, Qinyi Li, Hélène Angot, Lauriane L. J. Quéléver, Ivo Beck, Tiia Laurila, Lisa J. Beck, Matthew Boyer, Javier Carmona-García, Ana Borrego-Sánchez, Daniel Roca-Sanjuán, Otso Peräkylä, Roseline C. Thakur, Xu-Cheng He, Qiaozhi Zha, Dean Howard, Byron Blomquist, Stephen D. Archer, Ludovic Bariteau, Kevin Posman, Jacques Hueber, Detlev Helmig, Hans-Werner Jacobi, Heikki Junninen, Markku Kulmala, Anoop S. Mahajan, Andreas Massling, Henrik Skov, Mikko Sipilä, Joseph S. Francisco, Julia Schmale, Tuija Jokinen, and Alfonso Saiz-Lopez
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Science - Abstract
Observations are reported of HClO3 and HClO4 in the atmosphere and their widespread occurrence over the pan-Arctic during spring, providing further insights into atmospheric chlorine cycling in the polar environment.
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- 2023
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6. Year-round trace gas measurements in the central Arctic during the MOSAiC expedition
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Hélène Angot, Byron Blomquist, Dean Howard, Stephen Archer, Ludovic Bariteau, Ivo Beck, Matthew Boyer, Molly Crotwell, Detlev Helmig, Jacques Hueber, Hans-Werner Jacobi, Tuija Jokinen, Markku Kulmala, Xin Lan, Tiia Laurila, Monica Madronich, Donald Neff, Tuukka Petäjä, Kevin Posman, Lauriane Quéléver, Matthew D. Shupe, Isaac Vimont, and Julia Schmale
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Science - Abstract
Measurement(s) atmospheric ozone • atmospheric carbon dioxide • atmospheric methane • atmospheric carbon monoxide • atmospheric nitrous oxide • atmospheric dimethylsulfide • atmospheric sulfur dioxide • atmospheric gaseous elemental mercury • volatile organic compounds Technology Type(s) ozone analyzer • carbon dioxide analyzer • methane analyzer • carbon monoxide analyzer • nitrous oxide analyzer • dimethylsulfide analyzer • sulfur dioxide analyzer • gaseous elemental mercury analyzer • gas chromatography-mass spectrometry Sample Characteristic - Environment Atmosphere Sample Characteristic - Location central Arctic
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- 2022
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7. A central arctic extreme aerosol event triggered by a warm air-mass intrusion
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Lubna Dada, Hélène Angot, Ivo Beck, Andrea Baccarini, Lauriane L. J. Quéléver, Matthew Boyer, Tiia Laurila, Zoé Brasseur, Gina Jozef, Gijs de Boer, Matthew D. Shupe, Silvia Henning, Silvia Bucci, Marina Dütsch, Andreas Stohl, Tuukka Petäjä, Kaspar R. Daellenbach, Tuija Jokinen, and Julia Schmale
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Science - Abstract
Warm and moist air-mass intrusions into the Arctic are more frequent than the past decades. Here, the authors show that warm air mass intrusions from northern Eurasia inject record amounts of aerosols into the central Arctic Ocean strongly impacting atmospheric chemistry and cloud properties.
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- 2022
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8. Characterizing Atmospheric Transport Pathways to Antarctica and the Remote Southern Ocean Using Radon-222
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Scott D. Chambers, Susanne Preunkert, Rolf Weller, Sang-Bum Hong, Ruhi S. Humphries, Laura Tositti, Hélène Angot, Michel Legrand, Alastair G. Williams, Alan D. Griffiths, Jagoda Crawford, Jack Simmons, Taejin J. Choi, Paul B. Krummel, Suzie Molloy, Zoë Loh, Ian Galbally, Stephen Wilson, Olivier Magand, Francesca Sprovieri, Nicola Pirrone, and Aurélien Dommergue
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radon ,Southern Ocean ,Antarctica ,atmospheric transport ,MBL ,troposphere ,Science - Abstract
We discuss remote terrestrial influences on boundary layer air over the Southern Ocean and Antarctica, and the mechanisms by which they arise, using atmospheric radon observations as a proxy. Our primary motivation was to enhance the scientific community’s ability to understand and quantify the potential effects of pollution, nutrient or pollen transport from distant land masses to these remote, sparsely instrumented regions. Seasonal radon characteristics are discussed at 6 stations (Macquarie Island, King Sejong, Neumayer, Dumont d’Urville, Jang Bogo and Dome Concordia) using 1–4 years of continuous observations. Context is provided for differences observed between these sites by Southern Ocean radon transects between 45 and 67°S made by the Research Vessel Investigator. Synoptic transport of continental air within the marine boundary layer (MBL) dominated radon seasonal cycles in the mid-Southern Ocean site (Macquarie Island). MBL synoptic transport, tropospheric injection, and Antarctic outflow all contributed to the seasonal cycle at the sub-Antarctic site (King Sejong). Tropospheric subsidence and injection events delivered terrestrially influenced air to the Southern Ocean MBL in the vicinity of the circumpolar trough (or “Polar Front”). Katabatic outflow events from Antarctica were observed to modify trace gas and aerosol characteristics of the MBL 100–200 km off the coast. Radon seasonal cycles at coastal Antarctic sites were dominated by a combination of local radon sources in summer and subsidence of terrestrially influenced tropospheric air, whereas those on the Antarctic Plateau were primarily controlled by tropospheric subsidence. Separate characterization of long-term marine and katabatic flow air masses at Dumont d’Urville revealed monthly mean differences in summer of up to 5 ppbv in ozone and 0.3 ng m-3 in gaseous elemental mercury. These differences were largely attributed to chemical processes on the Antarctic Plateau. A comparison of our observations with some Antarctic radon simulations by global climate models over the past two decades indicated that: (i) some models overestimate synoptic transport to Antarctica in the MBL, (ii) the seasonality of the Antarctic ice sheet needs to be better represented in models, (iii) coastal Antarctic radon sources need to be taken into account, and (iv) the underestimation of radon in subsiding tropospheric air needs to be investigated.
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- 2018
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9. Large contribution of biomass burning emissions to ozone throughout the global remote troposphere
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Ilann Bourgeois, Jeff Peischl, J. Andrew Neuman, Steven S. Brown, Chelsea R. Thompson, Kenneth C. Aikin, Hannah M. Allen, Hélène Angot, Eric C. Apel, Colleen B. Baublitz, Jared F. Brewer, Pedro Campuzano-Jost, Róisín Commane, John D. Crounse, Bruce C. Daube, Joshua P. DiGangi, Glenn S. Diskin, Louisa K. Emmons, Arlene M. Fiore, Georgios I. Gkatzelis, Alan Hills, Rebecca S. Hornbrook, L. Gregory Huey, Jose L. Jimenez, Michelle Kim, Forrest Lacey, Kathryn McKain, Lee T. Murray, Benjamin A. Nault, David D. Parrish, Eric Ray, Colm Sweeney, David Tanner, Steven C. Wofsy, and Thomas B. Ryerson
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- 2021
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10. Aerosol source identification in the spring and summertime central Arctic Ocean using high-resolution mass spectrometry during MOSAiC
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Benjamin Heutte, Lubna Dada, Hélène Angot, Imad El Haddad, Gang Chen, Kaspar R. Dällenbach, Jakob B. Pernov, Ivo Beck, Lauriane Quéléver, Tiia Laurila, Tuija Jokinen, and Julia Schmale
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The Arctic region is undergoing considerable changes and is warming at a rate three to four times as fast as the rest of the world. Aerosols, which can originate from natural or anthropogenic sources, both of which can be locally emitted or long-range transported, play a crucial role in the Arctic radiative balance by directly absorbing or scattering incoming solar radiation or indirectly by changing cloud properties and modulating cloud formation mechanisms. Here, we investigate the sources of anthropogenic and natural aerosols in the central Arctic Ocean, using data collected during the Multidisciplinary drifting Observatory for the Study of Arctic Climate (MOSAiC) expedition with a high-resolution time-of-flight aerosol mass spectrometer. Using positive matrix factorization on the organic fraction of aerosols during spring and summertime (March – July), we identified six distinct chemical sources of organic aerosols (OA): a hydrocarbon-like factor, a Haze factor, two factors related to two extreme events of warm and moist air mass intrusions (WAMI) in mid-April, an Arctic oxygenated factor, and a Marine factor. We also describe the geographical origin of these factors, inferred from a potential source contribution function applied on 3-hourly back-trajectories. Together, these results suggest that OA from Eurasian anthropogenic origin (including the two extreme WAMI events in mid-April) dominate the central Arctic OA budget until at least the month of May, where episodic spikes in naturally-sourced marine OA, originating from the Fram Strait marginal ice-zone start to become important through June and July. We also highlight a hitherto unreported highly-oxygenated organic factor, whose temporal variability is closely related to that of particulate ammonium (maximum concentration in May) and whose geographical origin, in the Canadian archipelagoes, could indicate a co-emission mechanism of organic aerosols and ammonia from Arctic seabird colonies.
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- 2023
11. Characterization of blowing snow aerosol events in the central Arctic
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Nora Bergner, Ivo Beck, Kerri Pratt, Jessica Mirrielees, Jessie Creamean, Markus Frey, Benjamin Heutte, Hélène Angot, Steve Arnold, Janek Uin, Stephen Springston, Sergey Matrosov, Tiia Laurila, Tuija Jokinen, Lauriane Quéléver, Jakob Pernov, Xianda Gong, Jian Wang, and Julia Schmale
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Sea salt aerosols play a critical role in aerosol-radiation and aerosol-cloud interactions. Salty blowing snow has been hypothesized as an important source of sea salt aerosol in polar regions. The snow over sea ice can become salty by upward brine migration or deposition of sea spray produced from leads or transported from the ice edge. Wind-driven resuspension and sublimation of the snow is hypothesized to leave salty aerosol particles behind. Our understanding of aerosol emissions from blowing snow is based mainly on modeling studies, and direct observations to validate this process are sparse. The year-long Multidisciplinary drifting Observatory for the Study of Arctic Climate (MOSAiC) expedition, with its integrated measurements and sampling of frequent winter storms, is well suited to enhance our understanding of coupled Arctic system processes. Here, we focus on the impact of blowing snow and high wind speed events on aerosol number concentrations, size distributions, optical properties and cloud condensation nuclei (CCN) concentrations. Total aerosol number concentrations were significantly enhanced during high-wind speed periods, also concurrent with increased scattering aerosol coefficients and CCN concentrations. We further present a process-based characterization of the blowing snow events during MOSAiC and identify the influence of environmental variables on aerosol emissions. Our observations provide new insights into wind-driven aerosol in the central Arctic and may help to validate modelling studies and inform parameterization improvement particularly with respect to aerosol direct and indirect radiative forcing.
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- 2023
12. Stable mercury concentrations in tunas from the global ocean arise question about monitoring the effectiveness of the Minamata Convention
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Médieu, Anaïs, primary, Point, David, additional, Sonke, Jeroen, additional, Buchanan, Pearse, additional, Bodin, Nathalie, additional, Adams, Douglas, additional, Bignert, Anders, additional, Streets, David, additional, Hélène, Angot, additional, Ménard, Frédéric, additional, Choy, C. Anela, additional, Allain, Valérie, additional, Itai, Takaaki, additional, Bustamante, Paco, additional, Ferriss, Bridget, additional, Bourlès, Bernard, additional, Habasque, Jérémie, additional, Gauthier, Olivier, additional, and Lorrain, Anne, additional
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- 2023
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13. Modelling the coupled mercury-halogen-ozone cycle in the central Arctic during spring
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Shaddy Ahmed, Jennie L. Thomas, Hélène Angot, Aurélien Dommergue, Stephen D. Archer, Ludovic Bariteau, Ivo Beck, Nuria Benavent, Anne-Marlene Blechschmidt, Byron Blomquist, Matthew Boyer, Jesper H. Christensen, Sandro Dahlke, Ashu Dastoor, Detlev Helmig, Dean Howard, Hans-Werner Jacobi, Tuija Jokinen, Rémy Lapere, Tiia Laurila, Lauriane L. J. Quéléver, Andreas Richter, Andrei Ryjkov, Anoop S. Mahajan, Louis Marelle, Katrine Aspmo Pfaffhuber, Kevin Posman, Annette Rinke, Alfonso Saiz-Lopez, Julia Schmale, Henrik Skov, Alexandra Steffen, Geoff Stupple, Jochen Stutz, Oleg Travnikov, and Bianca Zilker
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Atmospheric Science ,Environmental Engineering ,Arctic ,Ozone ,Ecology ,Atmosphere ,Geology ,Mercury ,Geotechnical Engineering and Engineering Geology ,Oceanography ,Bromine ,Cryosphere - Abstract
Near-surface mercury and ozone depletion events occur in the lowest part of the atmosphere during Arctic spring. Mercury depletion is the first step in a process that transforms long-lived elemental mercury to more reactive forms within the Arctic that are deposited to the cryosphere, ocean, and other surfaces, which can ultimately get integrated into the Arctic food web. Depletion of both mercury and ozone occur due to the presence of reactive halogen radicals that are released from snow, ice, and aerosols. In this work, we added a detailed description of the Arctic atmospheric mercury cycle to our recently published version of the Weather Research and Forecasting model coupled with Chemistry (WRF-Chem 4.3.3) that includes Arctic bromine and chlorine chemistry and activation/recycling on snow and aerosols. The major advantage of our modelling approach is the online calculation of bromine concentrations and emission/recycling that is required to simulate the hourly and daily variability of Arctic mercury depletion. We used this model to study coupling between reactive cycling of mercury, ozone, and bromine during the Multidisciplinary drifting Observatory for the Study of Arctic Climate (MOSAiC) spring season in 2020 and evaluated results compared to land-based, ship-based, and remote sensing observations. The model predicts that elemental mercury oxidation is driven largely by bromine chemistry and that particulate mercury is the major form of oxidized mercury. The model predicts that the majority (74%) of oxidized mercury deposited to land-based snow is re-emitted to the atmosphere as gaseous elemental mercury, while a minor fraction (4%) of oxidized mercury that is deposited to sea ice is re-emitted during spring. Our work demonstrates that hourly differences in bromine/ozone chemistry in the atmosphere must be considered to capture the springtime Arctic mercury cycle, including its integration into the cryosphere and ocean.
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- 2023
14. Low ozone dry deposition rates to sea ice during the MOSAiC field campaign: Implications for the Arctic boundary layer ozone budget
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Johannes G.M. Barten, Laurens N. Ganzeveld, Gert-Jan Steeneveld, Byron W. Blomquist, Hélène Angot, Stephen D. Archer, Ludovic Bariteau, Ivo Beck, Matthew Boyer, Peter von der Gathen, Detlev Helmig, Dean Howard, Jacques Hueber, Hans-Werner Jacobi, Tuija Jokinen, Tiia Laurila, Kevin M. Posman, Lauriane Quéléver, Julia Schmale, Matthew D. Shupe, Maarten C. Krol, Deming, Jody W, and Miller, Lisa A
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Atmospheric Science ,Arctic ozone ,WIMEK ,Environmental Engineering ,Ecology ,Ozone deposition ,Geology ,Luchtkwaliteit ,Atmospheric boundary layer ,Geotechnical Engineering and Engineering Geology ,Oceanography ,Modelling ,Air Quality ,Meteorology ,Life Science ,Meteorologie - Abstract
Dry deposition to the surface is one of the main removal pathways of tropospheric ozone (O3). We quantified for the first time the impact of O3 deposition to the Arctic sea ice on the planetary boundary layer (PBL) O3 concentration and budget using year-round flux and concentration observations from the Multidisciplinary drifting Observatory for the Study of Arctic Climate (MOSAiC) campaign and simulations with a single-column atmospheric chemistry and meteorological model (SCM). Based on eddy-covariance O3 surface flux observations, we find a median surface resistance on the order of 20,000 s m−1, resulting in a dry deposition velocity of approximately 0.005 cm s−1. This surface resistance is up to an order of magnitude larger than traditionally used values in many atmospheric chemistry and transport models. The SCM is able to accurately represent the yearly cycle, with maxima above 40 ppb in the winter and minima around 15 ppb at the end of summer. However, the observed springtime ozone depletion events are not captured by the SCM. In winter, the modelled PBL O3 budget is governed by dry deposition at the surface mostly compensated by downward turbulent transport of O3 towards the surface. Advection, which is accounted for implicitly by nudging to reanalysis data, poses a substantial, mostly negative, contribution to the simulated PBL O3 budget in summer. During episodes with low wind speed (
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- 2023
15. A full year of aerosol size distribution data from the central Arctic under an extreme positive Arctic Oscillation:insights from the Multidisciplinary drifting Observatory for the Study of Arctic Climate (MOSAiC) expedition
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Matthew Boyer, Diego Aliaga, Jakob Boyd Pernov, Hélène Angot, Lauriane L. J. Quéléver, Lubna Dada, Benjamin Heutte, Manuel Dall'Osto, David C. S. Beddows, Zoé Brasseur, Ivo Beck, Silvia Bucci, Marina Duetsch, Andreas Stohl, Tiia Laurila, Eija Asmi, Andreas Massling, Daniel Charles Thomas, Jakob Klenø Nøjgaard, Tak Chan, Sangeeta Sharma, Peter Tunved, Radovan Krejci, Hans Christen Hansson, Federico Bianchi, Katrianne Lehtipalo, Alfred Wiedensohler, Kay Weinhold, Markku Kulmala, Tuukka Petäjä, Mikko Sipilä, Julia Schmale, Tuija Jokinen, European Commission, Academy of Finland, Department of Energy (US), Swiss Polar Institute, Agencia Estatal de Investigación (España), Institute for Atmospheric and Earth System Research (INAR), and Polar and arctic atmospheric research (PANDA)
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Marine boundary-layer ,Black carbon ,Atmospheric Science ,Clouds ,Summer ,Particle formation ,Number ,Air-pollution ,Transport ,Trends ,Polar ,114 Physical sciences - Abstract
27 pages, 12 figures, supplement https://doi.org/10.5194/acp-23-389-2023.-- Data availability: All data sets used in this work that were obtained during the MOSAiC campaign will be made publicly available by 1 January 2023 via PANGAEA (https://www.pangaea.de/, last access: June 2022) or are already publicly available in the Department of Energy Atmospheric Radiation Measurement program (ARM) user facility data discovery tool (https://adc.arm.gov/discovery/#/, last access: March 2022). Data from the PANGAEA archive include the following. Meteorological observations from Polarstern: Schmithüsen, H.: Continuous meteorological surface measurement during POLARSTERN cruise PS122/1. Alfred Wegener Institute, Helmholtz Centre for Polar and Marine Research, Bremerhaven, PANGAEA [data set], https://doi.org/10.1594/PANGAEA.935221, 2021a. Schmithüsen, H.: Continuous meteorological surface measurement during POLARSTERN cruise PS122/2. Alfred Wegener Institute, Helmholtz Centre for Polar and Marine Research, Bremerhaven, PANGAEA [data set], https://doi.org/10.1594/PANGAEA.935222, 2021b. Schmithüsen, H.: Continuous meteorological surface measurement during POLARSTERN cruise PS122/3. Alfred Wegener Institute, Helmholtz Centre for Polar and Marine Research, Bremerhaven, PANGAEA [data set], https://doi.org/10.1594/PANGAEA.935223, 2021c. Schmithüsen, H.: Continuous meteorological surface measurement during POLARSTERN cruise PS122/4. Alfred Wegener Institute, Helmholtz Centre for Polar and Marine Research, Bremerhaven, PANGAEA [data set], https://doi.org/10.1594/PANGAEA.935224, 2021d. Schmithüsen, H.: Continuous meteorological surface measurement during POLARSTERN cruise PS122/5. Alfred Wegener Institute, Helmholtz Centre for Polar and Marine Research, Bremerhaven, PANGAEA [data set], https://doi.org/10.1594/PANGAEA.935225, 2021e. Black carbon (BC): Heutte, B., Beck, I., Quéléver, L., Jokinen, T., Laurila, T., Dada, L., Schmale, J.: Equivalent black carbon concentration in 10 minutes time resolution, measured in the Swiss container during MOSAiC 2019/2020, PANGAEA [data set], https://doi.org/10.1594/PANGAEA.952251, 2022. Particle number concentration (CPC3025): Beck, I., Quéléver, L., Laurila, T., Jokinen, T., and Schmale, J.: Continuous corrected particle number concentration data in 10 sec resolution, measured in the Swiss aerosol container during MOSAiC 2019/2020, PANGAEA [data set], https://doi.org/10.1594/PANGAEA.941886, 2022b. The ARM data include the following: Kuang, C., Singh, A., and Howie, J.: Scanning mobility particle sizer (AOSSMPS), ARM [data set], https://doi.org/10.5439/1476898, 2022. Kuang, C., Salwen, C., Boyer, M., and Singh, A.: Condensation Particle Counter (AOSCPCF), ARM [data set], https://doi.org/10.5439/1046184, 2022. The land-based PNSD data: Alert: Personal communication from Tak Chan and Sangeeta Sharma, 2022 (for details, see Croft et al., 2016). Villum: Personal communication from Jakob Boyd Pernov, 2022 (for details, see Nguyen et al., 2016). Zeppelin: Personal communication from Peter Tunved, 2022 (for details, see Tunved et al., 2013). Tiksi: Personal communication from Eija Asmi, 2022 (for details, see Asmi et al., 2016). Utqiaġvik: Freud, E., Krejci, R., Tunved, P., Leaitch, W. R., Nguyen, Q. T., Massling, A., Skov, H., and Barrie, L.: Hourly mean homogenised (dry diameter range 20 to 500 nm) observations of aerosol number size distributions from station Barrow, 2007-09-20 to 2015-07-09, PANGAEA [data set], https://doi.org/10.1594/PANGAEA.877329, 2017b. The land-based BC data: Villum: Personal communications from Daniel Thomas, Jakob Klenø Nøjgaard, and Andreas Massling, 2022 (for details, see Thomas et al., 2022). NOAA Barrow Atmospheric Baseline Observatory (Utqiaġvik) during 2020: personal communication from Elisabeth Andrews, 2022 (for processing details, see Schmale et al., 2022). Gruvebadet. The PSAP data are accessible at the Italian Arctic Data Center operated by the National Research Council of Italy: https://data.iadc.cnr.it/erddap/tabledap/ebc_2010_2020.html (last access: December 2021, refer to Schmale et al., 2022, for additional details). All other BC data sets used in this work will be made publicly available on EBAS (http://ebas-data.nilu.no/, last access: December 2021, refer to Schmale et al., 2022, for additional details). The Arctic Oscillation (AO) data are publicly available from the NOAA and the National Weather Service: https://www.cpc.ncep.noaa.gov/products/precip/CWlink/daily_ao_index/ao.shtml (last access: June 2022). An archive of the FLEXPART model output and quick looks for the whole campaign can be found at https://img.univie.ac.at/webdata/mosaic (last access: March 2022), The Arctic environment is rapidly changing due to accelerated warming in the region. The warming trend is driving a decline in sea ice extent, which thereby enhances feedback loops in the surface energy budget in the Arctic. Arctic aerosols play an important role in the radiative balance and hence the climate response in the region, yet direct observations of aerosols over the Arctic Ocean are limited. In this study, we investigate the annual cycle in the aerosol particle number size distribution (PNSD), particle number concentration (PNC), and black carbon (BC) mass concentration in the central Arctic during the Multidisciplinary drifting Observatory for the Study of Arctic Climate (MOSAiC) expedition. This is the first continuous, year-long data set of aerosol PNSD ever collected over the sea ice in the central Arctic Ocean. We use a k-means cluster analysis, FLEXPART simulations, and inverse modeling to evaluate seasonal patterns and the influence of different source regions on the Arctic aerosol population. Furthermore, we compare the aerosol observations to land-based sites across the Arctic, using both long-term measurements and observations during the year of the MOSAiC expedition (2019–2020), to investigate interannual variability and to give context to the aerosol characteristics from within the central Arctic. Our analysis identifies that, overall, the central Arctic exhibits typical seasonal patterns of aerosols, including anthropogenic influence from Arctic haze in winter and secondary aerosol processes in summer. The seasonal pattern corresponds to the global radiation, surface air temperature, and timing of sea ice melting/freezing, which drive changes in transport patterns and secondary aerosol processes. In winter, the Norilsk region in Russia/Siberia was the dominant source of Arctic haze signals in the PNSD and BC observations, which contributed to higher accumulation-mode PNC and BC mass concentrations in the central Arctic than at land-based observatories. We also show that the wintertime Arctic Oscillation (AO) phenomenon, which was reported to achieve a record-breaking positive phase during January–March 2020, explains the unusual timing and magnitude of Arctic haze across the Arctic region compared to longer-term observations. In summer, the aerosol PNCs of the nucleation and Aitken modes are enhanced; however, concentrations were notably lower in the central Arctic over the ice pack than at land-based sites further south. The analysis presented herein provides a current snapshot of Arctic aerosol processes in an environment that is characterized by rapid changes, which will be crucial for improving climate model predictions, understanding link, This research has been supported by the Academy of Finland (grant no. 337552), Horizon 2020 (EMME-CARE, grant no. 856612), the US Department of Energy (grant no. DE-SC0022046), and the Swiss Polar Institute (grant no. 188478), With the institutional support of the ‘Severo Ochoa Centre of Excellence’ accreditation (CEX2019-000928-S)
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- 2023
16. Substantial contribution of iodine to Arctic ozone destruction
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Nuria Benavent, Anoop S. Mahajan, Qinyi Li, Carlos A. Cuevas, Julia Schmale, Hélène Angot, Tuija Jokinen, Lauriane L. J. Quéléver, Anne-Marlene Blechschmidt, Bianca Zilker, Andreas Richter, Jesús A. Serna, David Garcia-Nieto, Rafael P. Fernandez, Henrik Skov, Adela Dumitrascu, Patric Simões Pereira, Katarina Abrahamsson, Silvia Bucci, Marina Duetsch, Andreas Stohl, Ivo Beck, Tiia Laurila, Byron Blomquist, Dean Howard, Stephen D. Archer, Ludovic Bariteau, Detlev Helmig, Jacques Hueber, Hans-Werner Jacobi, Kevin Posman, Lubna Dada, Kaspar R. Daellenbach, Alfonso Saiz-Lopez, European Commission, Consejo Superior de Investigaciones Científicas (España), Academy of Finland, Ministry of Earth Sciences (India), Swiss National Science Foundation, Swiss Polar Institute, National Science Foundation (US), Ferring Pharmaceuticals, German Research Foundation, Mahajan, Anoop S., Li, Qinyi, Cuevas, Carlos A., Schmale, Julia, Angot, Hélène, Richter, Andreas, Fernandez, Rafael P., Skov, Henrik, Bucci, Silvia, Duetsch, Marina, Stohl, Andreas, Archer, Stephen D., Dada, Lubna, Daellenbach, Kaspar R., Saiz-Lopez, A., Institute for Atmospheric and Earth System Research (INAR), Polar and arctic atmospheric research (PANDA), and Air quality research group
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General Earth and Planetary Sciences ,114 Physical sciences - Abstract
6 pags., 2 figs., Unlike bromine, the effect of iodine chemistry on the Arctic surface ozone budget is poorly constrained. We present ship-based measurements of halogen oxides in the high Arctic boundary layer from the sunlit period of March to October 2020 and show that iodine enhances springtime tropospheric ozone depletion. We find that chemical reactions between iodine and ozone are the second highest contributor to ozone loss over the study period, after ozone photolysis-initiated loss and ahead of bromine., This study received funding from the European Research Council Executive Agency under the European Union’s Horizon 2020 Research and Innovation Program (project ERC‐2016‐COG 726349 CLIMAHAL and ERC-2016-STG 714621 GASPARCON) and the European Commission via the EMME-CARE project and was supported by the Consejo Superior de Investigaciones Científicas of Spain. This work was supported by the European Union’s Horizon 2020 Research and Innovation Programme under grant agreement no. 856612 and the Academy of Finland (project no. 334514). The Indian Institute of Tropical Meteorology is funded by the Ministry of Earth Sciences, Government of India. Ozone, CO, CH4 and AMS measurements were funded by the Swiss National Science Foundation (grant 200021_188478), the Swiss Polar Institute and U.S. National Science Foundation grants 1914781 and 1807163. J.S. holds the Ingvar Kamprad chair for extreme environments research, sponsored by Ferring Pharmaceuticals. Data reported in this manuscript were produced as part of the international MOSAiC expedition with tag MOSAiC20192020, with activities supported by Polarstern expedition AWI-PS122_00. H.S. was funded by the European ERA-PLANET projects iGOSP and iCUPE (consortium agreement no. 689443 for both projects). We thank FORMAS and the Swedish Polar Research Secretariat for support. We gratefully acknowledge funding by the Deutsche Forschungsgemeinschaft (project no. 268020496 – TRR 172) within the Transregional Collaborative Research Center ‘ArctiC Amplification: Climate Relevant Atmospheric and SurfaCe Processes, and Feedback Mechanisms (AC)3’ in subproject C03. We thank I. Bourgeois (NOAA/CIRES) for providing the ATom NOx data.
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- 2022
17. Arctic atmospheric mercury: Sources and changes
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Ashu Dastoor, Simon J. Wilson, Oleg Travnikov, Andrei Ryjkov, Hélène Angot, Jesper H. Christensen, Frits Steenhuisen, Marilena Muntean, and Arctic and Antarctic studies
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Air Pollutants ,Canada ,Environmental Engineering ,Arctic Regions ,Modeling ,Transport ,Mercury ,Pollution ,Anthropogenic ,Attribution ,Emissions ,Environmental Chemistry ,Deposition ,Waste Management and Disposal ,Environmental Monitoring - Abstract
Global anthropogenic and legacy mercury (Hg) emissions are the main sources of Arctic Hg contamination, primarily transported there via the atmosphere. This review summarizes the state of knowledge of the global anthropogenic sources of Hg emissions, and examines recent changes and source attribution of Hg transport and deposition to the Arctic using models. Estimated global anthropogenic Hg emissions to the atmosphere for 2015 were ~2220 Mg, ~20% higher than 2010. Global anthropogenic, legacy and geogenic Hg emissions were, respectively, responsible for 32%, 64% (wildfires: 6–10%) and 4% of the annual Arctic Hg deposition. Relative contributions to Arctic deposition of anthropogenic origin was dominated by sources in East Asia (32%), Commonwealth of Independent States (12%), and Africa (12%). Model results exhibit significant spatiotemporal variations in Arctic anthropogenic Hg deposition fluxes, driven by regional differences in Hg air transport routes, surface and precipitation uptake rates, and inter-seasonal differences in atmospheric circulation and deposition pathways. Model simulations reveal that changes in meteorology are having a profound impact on contemporary atmospheric Hg in the Arctic. Reversal of North Atlantic Oscillation phase from strongly negative in 2010 to positive in 2015, associated with lower temperature and more sea ice in the Canadian Arctic, Greenland and surrounding ocean, resulted in enhanced production of bromine species and Hg(0) oxidation and lower evasion of Hg(0) from ocean waters in 2015. This led to increased Hg(II) (and its deposition) and reduced Hg(0) air concentrations in these regions in line with High Arctic observations. However, combined changes in meteorology and anthropogenic emissions led to overall elevated modeled Arctic air Hg(0) levels in 2015 compared to 2010 contrary to observed declines at most monitoring sites, likely due to uncertainties in anthropogenic emission speciation, wildfire emissions and model representations of air-surface Hg fluxes.
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- 2022
18. Supplementary material to 'A full year of aerosol size distribution data from the central Arctic under an extreme positive Arctic Oscillation: Insights from the MOSAiC expedition'
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Matthew Boyer, Diego Aliaga, Jakob Boyd Pernov, Hélène Angot, Lauriane L. J. Quéléver, Lubna Dada, Benjamin Heutte, Manuel Dall’Osto, David C. S. Beddows, Zoé Brasseur, Ivo Beck, Silvia Bucci, Marina Duetsch, Andreas Stohl, Tiia Laurila, Eija Asmi, Andreas Massling, Daniel Charles Thomas, Jakob Klenø Nøjgaard, Tak Chan, Sangeeta Sharma, Peter Tunved, Radovan Krejci, Hans Christen Hansson, Markku Kulmala, Tuukka Petäjä, Mikko Sipilä, Julia Schmale, and Tuija Jokinen
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- 2022
19. A full year of aerosol size distribution data from the central Arctic under an extreme positive Arctic Oscillation: Insights from the MOSAiC expedition
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Matthew Boyer, Diego Aliaga, Jakob Boyd Pernov, Hélène Angot, Lauriane L. J. Quéléver, Lubna Dada, Benjamin Heutte, Manuel Dall’Osto, David C. S. Beddows, Zoé Brasseur, Ivo Beck, Silvia Bucci, Marina Duetsch, Andreas Stohl, Tiia Laurila, Eija Asmi, Andreas Massling, Daniel Charles Thomas, Jakob Klenø Nøjgaard, Tak Chan, Sangeeta Sharma, Peter Tunved, Radovan Krejci, Hans Christen Hansson, Markku Kulmala, Tuukka Petäjä, Mikko Sipilä, Julia Schmale, and Tuija Jokinen
- Abstract
The Arctic environment is rapidly changing due to accelerated warming in the region. The warming trend is driving a decline in sea ice extent, which thereby enhances feedback loops in the surface energy budget in the Arctic. Arctic aerosols play an important role in the radiative balance, and hence the climate response, in the region; yet direct observations of aerosols over the Arctic Ocean are limited. In this study, we investigate the annual cycle in the aerosol particle number size distribution (PNSD), particle number concentration (PNC), and black carbon (BC) mass concentration in the central Arctic during the Multidisciplinary drifting Observatory for the Study of Arctic Climate (MOSAiC) expedition. This is the first continuous, year-long dataset of aerosol PNSD ever collected over the sea ice in the central Arctic Ocean. We use a k-means cluster analysis, FLEXPART simulations, and inverse modeling to evaluate seasonal patterns and the influence of different source regions on the Arctic aerosol population. Furthermore, we compare the aerosol observations to land-based sites across the Arctic, using both long-term measurements and observations during the year of the MOSAiC expedition (2019–2020), to investigate interannual variability and to give context to the aerosol characteristics from within the central Arctic. Our analysis identifies that, overall, the central Arctic exhibits typical seasonal patterns of aerosols, including anthropogenic influence from Arctic Haze in winter and secondary aerosol processes in summer. The seasonal pattern corresponds with the global radiation, surface air temperature, and the timing of sea ice melting/freezing, which drives changes in transport patterns and secondary aerosol processes. In winter, the Norilsk region in Russia/Siberia was the dominant source of Arctic Haze signal in the PNSD and BC observations, which contributed to higher accumulation mode PNC and BC mass concentration in the central Arctic than at land-based observatories. We also show that the wintertime Arctic Oscillation (AO) phenomenon, which was reported to achieve a record-breaking positive phase during January–March 2020, explains the unusual timing and magnitude of Arctic Haze across the Arctic region compared to longer-term observations. In summer, the PNC of nucleation and Aitken mode aerosol is enhanced, but concentrations were notably lower in the central Arctic over the ice pack than at land-based sites further south. The analysis presented herein provides a current snapshot of Arctic aerosol processes in an environment that is characterized by rapid changes, which will be crucial for improving climate model predictions, understanding linkages between different environmental processes, and investigating the impacts of climate change in future Arctic aerosol studies.
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- 2022
20. Supplementary material to 'Atmospheric biogenic volatile organic compounds in the Alaskan Arctic tundra: constraints from measurements at Toolik Field Station'
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Vanessa Selimovic, Damien Ketcherside, Sreelekha Chaliyakunnel, Catie Wielgasz, Wade Permar, Hélène Angot, Dylan B. Millet, Alan Fried, Detlev Helmig, and Lu Hu
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- 2022
21. Atmospheric biogenic volatile organic compounds in the Alaskan Arctic tundra: constraints from measurements at Toolik Field Station
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Vanessa Selimovic, Damien Ketcherside, Sreelekha Chaliyakunnel, Catherine Wielgasz, Wade Permar, Hélène Angot, Dylan B. Millet, Alan Fried, Detlev Helmig, and Lu Hu
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oh reactivity measurements ,Atmospheric Science ,gas-phase reactions ,model ,photochemical data ,satellite ,boreal forest ,isoprene emissions ,chemistry ,mixing ratios ,formic-acid - Abstract
The Arctic is a climatically sensitive region that has experienced warming at almost 3 times the global average rate in recent decades, leading to an increase in Arctic greenness and a greater abundance of plants that emit biogenic volatile organic compounds (BVOCs). These changes in atmospheric emissions are expected to significantly modify the overall oxidative chemistry of the region and lead to changes in VOC composition and abundance, with implications for atmospheric processes. Nonetheless, observations needed to constrain our current understanding of these issues in this critical environment are sparse. This work presents novel atmospheric in situ proton-transfer-reaction time-of-flight mass spectrometry (PTR-ToF-MS) measurements of VOCs at Toolik Field Station (TFS; 68∘38′ N, 149∘36' W), in the Alaskan Arctic tundra during May–June 2019. We employ a custom nested grid version of the GEOS-Chem chemical transport model (CTM), driven with MEGANv2.1 (Model of Emissions of Gases and Aerosols from Nature version 2.1) biogenic emissions for Alaska at 0.25∘ × 0.3125∘ resolution, to interpret the observations in terms of their constraints on BVOC emissions, total reactive organic carbon (ROC) composition, and calculated OH reactivity (OHr) in this environment. We find total ambient mole fraction of 78 identified VOCs to be 6.3 ± 0.4 ppbv (10.8 ± 0.5 ppbC), with overwhelming (> 80 %) contributions are from short-chain oxygenated VOCs (OVOCs) including methanol, acetone and formaldehyde. Isoprene was the most abundant terpene identified. GEOS-Chem captures the observed isoprene (and its oxidation products), acetone and acetaldehyde abundances within the combined model and observation uncertainties (±25 %), but underestimates other OVOCs including methanol, formaldehyde, formic acid and acetic acid by a factor of 3 to 12. The negative model bias for methanol is attributed to underestimated biogenic methanol emissions for the Alaskan tundra in MEGANv2.1. Observed formaldehyde mole fractions increase exponentially with air temperature, likely reflecting its biogenic precursors and pointing to a systematic model underprediction of its secondary production. The median campaign-calculated OHr from VOCs measured at TFS was 0.7 s−1, roughly 5 % of the values typically reported in lower-latitude forested ecosystems. Ten species account for over 80 % of the calculated VOC OHr, with formaldehyde, isoprene and acetaldehyde together accounting for nearly half of the total. Simulated OHr based on median-modeled VOCs included in GEOS-Chem averages 0.5 s−1 and is dominated by isoprene (30 %) and monoterpenes (17 %). The data presented here serve as a critical evaluation of our knowledge of BVOCs and ROC budgets in high-latitude environments and represent a foundation for investigating and interpreting future warming-driven changes in VOC emissions in the Alaskan Arctic tundra.
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- 2022
22. Atmospheric mercury sources in a coastal-urban environment: a case study in Boston, Massachusetts, USA
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M. R. Sargent, Steven C. Wofsy, Emma Rutkowski, Hélène Angot, Daniel Obrist, Dean Howard, Lucy R. Hutyra, and Noelle E. Selin
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010504 meteorology & atmospheric sciences ,Range (biology) ,Oceans and Seas ,Atmospheric mercury ,chemistry.chemical_element ,010501 environmental sciences ,Management, Monitoring, Policy and Law ,Atmospheric sciences ,01 natural sciences ,Wind speed ,Human health ,Humans ,Environmental Chemistry ,0105 earth and related environmental sciences ,Air Pollutants ,Public Health, Environmental and Occupational Health ,Northern Hemisphere ,Mercury ,General Medicine ,Metropolitan area ,Mercury (element) ,Massachusetts ,chemistry ,13. Climate action ,Environmental science ,Urban environment ,Boston ,Environmental Monitoring - Abstract
Mercury (Hg) is an environmental toxicant dangerous to human health and the environment. Its anthropogenic emissions are regulated by global, regional, and local policies. Here, we investigate Hg sources in the coastal city of Boston, the third largest metropolitan area in the Northeastern United States. With a median of 1.37 ng m-3, atmospheric Hg concentrations measured from August 2017 to April 2019 were at the low end of the range reported in the Northern Hemisphere and in the range reported at North American rural sites. Despite relatively low ambient Hg concentrations, we estimate anthropogenic emissions to be 3-7 times higher than in current emission inventories using a measurement-model framework, suggesting an underestimation of small point and/or nonpoint emissions. We also test the hypothesis that a legacy Hg source from the ocean contributes to atmospheric Hg concentrations in the study area; legacy emissions (recycling of previously deposited Hg) account for ∼60% of Hg emitted annually worldwide (and much of this recycling takes place through the oceans). We find that elevated concentrations observed during easterly oceanic winds can be fully explained by low wind speeds and recirculating air allowing for accumulation of land-based emissions. This study suggests that the influence of nonpoint land-based emissions may be comparable in size to point sources in some regions and highlights the benefits of further top-down studies in other areas.
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- 2021
23. Biogenic volatile organic compound ambient mixing ratios and emission rates in the Alaskan Arctic tundra
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Detlev Helmig, Kaixin Cui, Jacques Hueber, Jacob Moss, Catherine Wielgasz, Damien Ketcherside, M. Syndonia Bret-Harte, Dylan B. Millet, Lu Hu, Tyler Milligan, Katelyn McErlean, and Hélène Angot
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0106 biological sciences ,010504 meteorology & atmospheric sciences ,lcsh:Life ,Growing season ,Atmospheric sciences ,01 natural sciences ,Atmosphere ,chemistry.chemical_compound ,lcsh:QH540-549.5 ,Volatile organic compound ,Ecology, Evolution, Behavior and Systematics ,Isoprene ,0105 earth and related environmental sciences ,Earth-Surface Processes ,chemistry.chemical_classification ,lcsh:QE1-996.5 ,Taiga ,15. Life on land ,Tundra ,lcsh:Geology ,lcsh:QH501-531 ,chemistry ,Arctic ,Boreal ,13. Climate action ,Environmental science ,lcsh:Ecology ,010606 plant biology & botany - Abstract
Rapid Arctic warming, a lengthening growing season, and the increasing abundance of biogenic volatile-organic-compound-emitting shrubs are all anticipated to increase atmospheric biogenic volatile organic compounds (BVOCs) in the Arctic atmosphere, with implications for atmospheric oxidation processes and climate feedbacks. Quantifying these changes requires an accurate understanding of the underlying processes driving BVOC emissions in the Arctic. While boreal ecosystems have been widely studied, little attention has been paid to Arctic tundra environments. Here, we report terpenoid (isoprene, monoterpenes, and sesquiterpenes) ambient mixing ratios and emission rates from key dominant vegetation species at Toolik Field Station (TFS; 68∘38′ N, 149∘36′ W) in northern Alaska during two back-to-back field campaigns (summers of 2018 and 2019) covering the entire growing season. Isoprene ambient mixing ratios observed at TFS fell within the range of values reported in the Eurasian taiga (0–500 parts per trillion by volume – pptv), while monoterpene and sesquiterpene ambient mixing ratios were respectively close to and below the instrumental quantification limit (∼2 pptv). Isoprene surface emission rates ranged from 0.2 to 2250 µgC m−2 h−1 (mean of 85 µgC m−2 h−1) and monoterpene emission rates remained, on average, below 1 µgC m−2 h−1 over the course of the study. We further quantified the temperature dependence of isoprene emissions from local vegetation, including Salix spp. (a known isoprene emitter), and compared the results to predictions from the Model of Emissions of Gases and Aerosols from Nature version 2.1 (MEGAN2.1). Our observations suggest a 180 %–215 % emission increase in response to a 3–4 ∘C warming, and the MEGAN2.1 temperature algorithm exhibits a close fit with observations for enclosure temperatures in the 0–30 ∘C range. The data presented here provide a baseline for investigating future changes in the BVOC emission potential of the under-studied Arctic tundra environment.
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- 2020
24. Evidence that Pacific tuna mercury levels are driven by marine methylmercury production and anthropogenic inputs
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Anaïs Médieu, David Point, Takaaki Itai, Hélène Angot, Pearse J. Buchanan, Valérie Allain, Leanne Fuller, Shane Griffiths, David P. Gillikin, Jeroen E. Sonke, Lars-Eric Heimbürger-Boavida, Marie-Maëlle Desgranges, Christophe E. Menkes, Daniel J. Madigan, Pablo Brosset, Olivier Gauthier, Alessandro Tagliabue, Laurent Bopp, Anouk Verheyden, Anne Lorrain, Laboratoire des Sciences de l'Environnement Marin (LEMAR) (LEMAR), Institut de Recherche pour le Développement (IRD)-Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER)-Université de Brest (UBO)-Institut Universitaire Européen de la Mer (IUEM), Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Brest (UBO)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Brest (UBO)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS), Géosciences Environnement Toulouse (GET), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire Midi-Pyrénées (OMP), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Centre National de la Recherche Scientifique (CNRS), Department of Earth and Planetary Science [Tokyo], Graduate School of Science [Tokyo], The University of Tokyo (UTokyo)-The University of Tokyo (UTokyo), Extreme Environments Research Laboratory (EERL), Ecole Polytechnique Fédérale de Lausanne (EPFL), Department of Earth Ocean and Ecological Sciences [Liverpool], University of Liverpool, Communauté du Pacifique/Pacific Community, Inter-American Tropical Tuna Commission (IATTC), Union College, Institut méditerranéen d'océanologie (MIO), Institut de Recherche pour le Développement (IRD)-Aix Marseille Université (AMU)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Toulon (UTLN)-Centre National de la Recherche Scientifique (CNRS), Ecologie marine tropicale dans les Océans Pacifique et Indien (ENTROPIE [Réunion]), Institut de Recherche pour le Développement (IRD)-Université de La Réunion (UR)-Centre National de la Recherche Scientifique (CNRS), University of Windsor [Ca], Dynamique et durabilité des écosystèmes : de la source à l’océan (DECOD), Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE), Laboratoire de Météorologie Dynamique (UMR 8539) (LMD), Institut national des sciences de l'Univers (INSU - CNRS)-École polytechnique (X)-École des Ponts ParisTech (ENPC)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Département des Géosciences - ENS Paris, École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL), Institut de Recherche pour le Développement (IRD), ANR-17-CE34-0010 MERTOX, ANR-17-EURE-0015,ISBlue,Interdisciplinary Graduate School for the Blue planet(2017), ANR-17-CE34-0010,MERTOX,Découvrir l'origine de la toxine methylmercure dans les écosystèmes marins(2017), Observatoire Midi-Pyrénées (OMP), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France, Oceanic Fisheries Programme, INSU Division Technique de l'INSU [Site de Brest], Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), University of Windsor, Windsor, ON, N9B 3P4, Canada, Université de Brest (UBO), and PacificFundVACOPA Project (spatial VAriations of COntaminants levels in PAcificoceantrophic webs)
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Geologic Sediments ,Asia ,Food Chain ,010504 meteorology & atmospheric sciences ,[SDV]Life Sciences [q-bio] ,[SDE.MCG]Environmental Sciences/Global Changes ,skipjack tuna ,010501 environmental sciences ,01 natural sciences ,Sustainability Science ,Methylation ,atmospheric inputs ,spatial modeling ,biogeochemistry ,Animals ,Humans ,Seawater ,Water Pollutants ,14. Life underwater ,0105 earth and related environmental sciences ,[SDU.OCEAN]Sciences of the Universe [physics]/Ocean, Atmosphere ,Multidisciplinary ,Pacific Ocean ,Ecology ,Tuna ,food and beverages ,methylmercury ,Methylmercury ,Mercury ,Biological Sciences ,Methylmercury Compounds ,Models, Theoretical ,Europe ,Seafood ,13. Climate action ,North America ,[SDE]Environmental Sciences ,[SDE.BE]Environmental Sciences/Biodiversity and Ecology ,human activities ,Environmental Sciences ,Water Pollutants, Chemical ,Environmental Monitoring - Abstract
Significance Humans are exposed to toxic methylmercury mainly by consuming marine fish. New environmental policies under the Minamata Convention rely on a yet-poorly-known understanding of how mercury emissions translate into fish methylmercury levels. Here, we provide the first detailed map of mercury concentrations from skipjack tuna across the Pacific. Our study shows that the natural functioning of the global ocean has an important influence on tuna mercury concentrations, specifically in relation to the depth at which methylmercury concentrations peak in the water column. However, mercury inputs originating from anthropogenic sources are also detectable, leading to enhanced tuna mercury levels in the northwestern Pacific Ocean that cannot be explained solely by oceanic processes., Pacific Ocean tuna is among the most-consumed seafood products but contains relatively high levels of the neurotoxin methylmercury. Limited observations suggest tuna mercury levels vary in space and time, yet the drivers are not well understood. Here, we map mercury concentrations in skipjack tuna across the Pacific Ocean and build generalized additive models to quantify the anthropogenic, ecological, and biogeochemical drivers. Skipjack mercury levels display a fivefold spatial gradient, with maximum concentrations in the northwest near Asia, intermediate values in the east, and the lowest levels in the west, southwest, and central Pacific. Large spatial differences can be explained by the depth of the seawater methylmercury peak near low-oxygen zones, leading to enhanced tuna mercury concentrations in regions where oxygen depletion is shallow. Despite this natural biogeochemical control, the mercury hotspot in tuna caught near Asia is explained by elevated atmospheric mercury concentrations and/or mercury river inputs to the coastal shelf. While we cannot ignore the legacy mercury contribution from other regions to the Pacific Ocean (e.g., North America and Europe), our results suggest that recent anthropogenic mercury release, which is currently largest in Asia, contributes directly to present-day human mercury exposure.
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- 2022
25. Mercury in the Cryosphere
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Hélène Angot, Lars-Eric Heimbürger-Boavida, Ashu Dastoor, Alexandre J. Poulain, Aurélien Dommergue, Alexandra Steffen, Daniel Obrist, Institut méditerranéen d'océanologie (MIO), and Institut de Recherche pour le Développement (IRD)-Aix Marseille Université (AMU)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Toulon (UTLN)-Centre National de la Recherche Scientifique (CNRS)
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chemistry ,Environmental chemistry ,[SDE]Environmental Sciences ,Cryosphere ,chemistry.chemical_element ,Environmental science ,ComputingMilieux_MISCELLANEOUS ,Mercury (element) - Abstract
International audience
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- 2022
26. Overview of the MOSAiC expedition- Atmosphere
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Matthew D. Shupe, Markus Rex, Byron Blomquist, P. Ola G. Persson, Julia Schmale, Taneil Uttal, Dietrich Althausen, Hélène Angot, Stephen Archer, Ludovic Bariteau, Ivo Beck, John Bilberry, Silvia Bucci, Clifton Buck, Matt Boyer, Zoé Brasseur, Ian M. Brooks, Radiance Calmer, John Cassano, Vagner Castro, David Chu, David Costa, Christopher J. Cox, Jessie Creamean, Susanne Crewell, Sandro Dahlke, Ellen Damm, Gijs de Boer, Holger Deckelmann, Klaus Dethloff, Marina Dütsch, Kerstin Ebell, André Ehrlich, Jody Ellis, Ronny Engelmann, Allison A. Fong, Markus M. Frey, Michael R. Gallagher, Laurens Ganzeveld, Rolf Gradinger, Jürgen Graeser, Vernon Greenamyer, Hannes Griesche, Steele Griffiths, Jonathan Hamilton, Günther Heinemann, Detlev Helmig, Andreas Herber, Céline Heuzé, Julian Hofer, Todd Houchens, Dean Howard, Jun Inoue, Hans-Werner Jacobi, Ralf Jaiser, Tuija Jokinen, Olivier Jourdan, Gina Jozef, Wessley King, Amelie Kirchgaessner, Marcus Klingebiel, Misha Krassovski, Thomas Krumpen, Astrid Lampert, William Landing, Tiia Laurila, Dale Lawrence, Michael Lonardi, Brice Loose, Christof Lüpkes, Maximilian Maahn, Andreas Macke, Wieslaw Maslowski, Christopher Marsay, Marion Maturilli, Mario Mech, Sara Morris, Manuel Moser, Marcel Nicolaus, Paul Ortega, Jackson Osborn, Falk Pätzold, Donald K. Perovich, Tuukka Petäjä, Christian Pilz, Roberta Pirazzini, Kevin Posman, Heath Powers, Kerri A. Pratt, Andreas Preußer, Lauriane Quéléver, Martin Radenz, Benjamin Rabe, Annette Rinke, Torsten Sachs, Alexander Schulz, Holger Siebert, Tercio Silva, Amy Solomon, Anja Sommerfeld, Gunnar Spreen, Mark Stephens, Andreas Stohl, Gunilla Svensson, Janek Uin, Juarez Viegas, Christiane Voigt, Peter von der Gathen, Birgit Wehner, Jeffrey M. Welker, Manfred Wendisch, Martin Werner, ZhouQing Xie, Fange Yue, Institut des Géosciences de l’Environnement (IGE), Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP ), and Université Grenoble Alpes (UGA)
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[SDU.OCEAN]Sciences of the Universe [physics]/Ocean, Atmosphere ,Atmospheric Science ,Environmental Engineering ,WIMEK ,Ecology ,Atmosphere ,Geology ,clouds ,Luchtkwaliteit ,Geotechnical Engineering and Engineering Geology ,Oceanography ,Air Quality ,MOSAIC ,Arctic ,Field campaign ,arctic ,[SDU.STU.GL]Sciences of the Universe [physics]/Earth Sciences/Glaciology - Abstract
International audience; With the Arctic rapidly changing, the needs to observe, understand, and model the changes are essential. To support these needs, an annual cycle of observations of atmospheric properties, processes, and interactions were made while drifting with the sea ice across the central Arctic during the Multidisciplinary drifting Observatory for the Study of Arctic Climate (MOSAiC) expedition from October 2019 to September 2020. An international team designed and implemented the comprehensive program to document and characterize all aspects of the Arctic atmospheric system in unprecedented detail, using a variety of approaches, and across multiple scales. These measurements were coordinated with other observational teams to explore cross-cutting and coupled interactions with the Arctic Ocean, sea ice, and ecosystem through a variety of physical and biogeochemical processes. This overview outlines the breadth and complexity of the atmospheric research program, which was organized into 4 subgroups: atmospheric state, clouds and precipitation, gases and aerosols, and energy budgets. Atmospheric variability over the annual cycle revealed important influences from a persistent large-scale winter circulation pattern, leading to some storms with pressure and winds that were outside the interquartile range of past conditions suggested by long-term reanalysis. Similarly, the MOSAiC location was warmer and wetter in summer than the reanalysis climatology, in part due to its close proximity to the sea ice edge. The comprehensiveness of the observational program for characterizing and analyzing atmospheric phenomena is demonstrated via a winter case study examining air mass transitions and a summer case study examining vertical atmospheric evolution. Overall, the MOSAiC atmospheric program successfully met its objectives and was the most comprehensive atmospheric measurement program to date conducted over the Arctic sea ice. The obtained data will support a broad range of coupled-system scientific research and provide an important foundation for advancing multiscale modeling capabilities in the Arctic.
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- 2022
27. What are the likely changes in mercury concentration in the Arctic atmosphere and ocean under future emissions scenarios?
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Amina T. Schartup, Anne L. Soerensen, Hélène Angot, Katlin Bowman, and Noelle E. Selin
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Environmental Engineering ,Arctic Regions ,Atmosphere ,Oceans and Seas ,Environmental Chemistry ,Water ,Mercury ,Pollution ,Waste Management and Disposal ,Environmental Monitoring - Abstract
Arctic mercury (Hg) concentrations respond to changes in anthropogenic Hg emissions and environmental change. This manuscript, prepared for the 2021 Arctic Monitoring and Assessment Programme Mercury Assessment, explores the response of Arctic Ocean Hg concentrations to changing primary Hg emissions and to changing sea-ice cover, river inputs, and net primary production. To do this, we conduct a model analysis using a 2015 Hg inventory and future anthropogenic Hg emission scenarios. We model future atmospheric Hg deposition to the surface ocean as a flux to the surface water or sea ice using three scenarios: No Action, New Policy (NP), and Maximum Feasible Reduction (MFR). We then force a five-compartment box model of Hg cycling in the Arctic Ocean with these scenarios and literature-derived climate variables to simulate environmental change. No Action results in a 51% higher Hg deposition rate by 2050 while increasing Hg concentrations in the surface water by 22% and9% at depth. Both "action" scenarios (NP and MFR), implemented in 2020 or 2035, result in lower Hg deposition ranging from 7% (NP delayed to 2035) to 30% (MFR implemented in 2020) by 2050. Under this last scenario, ocean Hg concentrations decline by 14% in the surface and 4% at depth. We find that the sea-ice cover decline exerts the strongest Hg reducing forcing on the Arctic Ocean while increasing river discharge increases Hg concentrations. When modified together the climate scenarios result in a ≤5% Hg decline by 2050 in the Arctic Ocean. Thus, we show that the magnitude of emissions-induced future changes in the Arctic Ocean is likely to be substantial compared to climate-induced effects. Furthermore, this study underscores the need for prompt and ambitious action for changing Hg concentrations in the Arctic, since delaying less ambitious reduction measures-like NP-until 2035 may become offset by Hg accumulated from pre-2035 emissions.
- Published
- 2021
28. Supplementary material to 'Temporary pause in the growth of atmospheric ethane and propane in 2015–2018'
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Hélène Angot, Connor Davel, Christine Wiedinmyer, Gabrielle Pétron, Jashan Chopra, Jacques Hueber, Brendan Blanchard, Ilann Bourgeois, Isaac Vimont, Stephen A. Montzka, Ben R. Miller, James W. Elkins, and Detlev Helmig
- Published
- 2021
29. Atmospheric oil and natural gas hydrocarbon trends in the Northern Colorado Front Range are notably smaller than inventory emissions reductions
- Author
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B. D. Hall, Molly Crotwell, Edward J. Dlugokencky, C. Siso, Arlyn E. Andrews, Detlev Helmig, Benjamin R. Miller, Russell C. Schnell, Stephen A. Montzka, Pieter P. Tans, J. Kofler, Sonja Wolter, Samuel J. Oltmans, Gabrielle Pétron, Hélène Angot, and Lucy Cheadle
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chemistry.chemical_classification ,Atmospheric Science ,Environmental Engineering ,010504 meteorology & atmospheric sciences ,Ecology ,business.industry ,Range (biology) ,Front (oceanography) ,Geology ,010501 environmental sciences ,Geotechnical Engineering and Engineering Geology ,Oceanography ,Mole fraction ,01 natural sciences ,Methane ,chemistry.chemical_compound ,Hydrocarbon ,chemistry ,Natural gas ,Propane ,TRACER ,Environmental chemistry ,Environmental science ,business ,0105 earth and related environmental sciences - Abstract
From 2008 to mid-2016, there was more than a 7-fold increase in oil production and nearly a tripling of natural gas production in the Colorado Denver–Julesburg Basin (DJB). This study utilized air samples collected at the Boulder Atmospheric Observatory (BAO) tower in southwestern Weld County in the DJB to investigate atmospheric mole fraction trends of methane and volatile organic compounds (VOCs). Elevated methane and propane mole fractions and low values (
- Published
- 2021
30. A top-down emissions estimation in the Boston urban region suggests an underestimation of small point and/or non-point mercury emissions
- Author
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Steven C. Wofsy, Hélène Angot, M. R. Sargent, Dean Howard, Daniel Obrist, Lucy R. Hutyra, Noelle E. Selin, and Emma Rutkowski
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Urban region ,Estimation ,chemistry ,Environmental science ,chemistry.chemical_element ,Point (geometry) ,Atmospheric sciences ,Mercury (element) - Published
- 2021
31. Seasonal Variation of Mercury and Its Isotopes in Atmospheric Particles at the Coastal Zhongshan Station, Eastern Antarctica
- Author
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Minghu Ding, Shichang Kang, Wang Zheng, Chuanjin Li, Jiubin Chen, Hélène Angot, Dahe Qin, Xiangyu Ma, Guitao Shi, Qianggong Zhang, Jiawen Ren, Cunde Xiao, and Zhiheng Du
- Subjects
Katabatic wind ,Isotope ,chemistry.chemical_element ,Antarctic Regions ,General Chemistry ,Fractionation ,Mercury ,010501 environmental sciences ,Seasonality ,medicine.disease ,01 natural sciences ,Mercury (element) ,Mercury Isotopes ,chemistry ,Isotopes ,Environmental chemistry ,medicine ,Environmental Chemistry ,Particulate mercury ,Environmental science ,Trace metal ,Seasons ,Cycling ,0105 earth and related environmental sciences ,Environmental Monitoring - Abstract
Mercury (Hg) is a globally spread trace metal due to its long atmospheric residence time. Yet, our understanding of atmospheric processes (e.g., redox reactions and deposition) driving Hg cycling is still limited, especially in polar regions. The Antarctic continent, by virtue of its remoteness, is the perfect location to investigate Hg atmospheric processes in the absence of significant local anthropogenic impact. Here, we present the first 2 year record (2016-2017) of total suspended particulate mercury (PHg) concentrations along with a year-round determination of an Hg stable isotopic composition in particles collected at Zhongshan Station (ZSS), eastern Antarctic coast. The mean PHg concentration is 21.8 ± 32.1 pg/m3, ranging from 0.9 to 195.6 pg/m3, and peaks in spring and summer. The negative mass-independent fractionation of odd Hg isotopes (odd-MIF, average -0.38 ± 0.12‰ for Δ199Hg) and the slope of Δ199Hg/Δ201Hg with 0.91 ± 0.12 suggest that the springtime isotope variation of PHg is likely caused by in situ photo-oxidation and reduction reactions. On the other hand, the increase of PHg concentrations and the observed odd-MIF values in summer are attributed to the transport by katabatic winds of divalent species derived from the oxidation of elemental Hg in the inland Antarctic Plateau.
- Published
- 2020
32. Atmospheric mercury in the southern hemisphere – Part 1: Trend and inter-annual variations of atmospheric mercury at Cape Point, South Africa, in 2007–2017, and on Amsterdam Island in 2012–2017
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Franz Slemr, Lynwill Martin, Casper Labuschagne, Thumeka Mokolo, Hélène Angot, Olivier Magand, Aurélien Dommergue, Philippe Garat, Michel Ramonet, and Johannes Bieser
- Abstract
The Minamata Convention on mercury (Hg) entered into force in 2017, committing its 116 parties (as of January 2019) to curb anthropogenic emissions. Monitoring of atmospheric concentrations and trends is an important part of the effectiveness evaluation of the Convention. A few years ago (in 2017) we reported an increasing trend of atmospheric Hg concentrations at the Cape Point Global Atmospheric Watch (GAW) station in South Africa (34°21' S, 18°29' E) for the 2007–2015 period. With 2 more years of measurements at Cape Point and the 2012–2017 data from Amsterdam Island (37°48' S, 77°34' E) in the remote southern Indian Ocean, a more complex picture emerges: at Cape Point the upward trend for the 2007–2017 period is still significant but none or slightly downward trend was detected for the period 2012–2017 both at Cape Point and Amsterdam Island. The upward trend at Cape Point is thus driven mainly by the 2007–2014 data. Using ancillary data on 222Rn, CO, O3, CO2, and CH4 from Cape Point and Amsterdam Island the possible reasons for the trend and its change are investigated. In a companion paper this analysis is extended for the Cape Point station by calculations of source and sink regions using backward trajectory analysis.
- Published
- 2020
33. Supplementary material to 'Atmospheric mercury in the southern hemisphere – Part 1: Trend and inter-annual variations of atmospheric mercury at Cape Point, South Africa, in 2007–2017, and on Amsterdam Island in 2012–2017'
- Author
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Franz Slemr, Lynwill Martin, Casper Labuschagne, Thumeka Mokolo, Hélène Angot, Olivier Magand, Aurélien Dommergue, Philippe Garat, Michel Ramonet, and Johannes Bieser
- Published
- 2020
34. Mercury in precipitated and surface snow at Dome C and a first estimate of mercury depositional fluxes during the Austral summer on the high Antarctic plateau
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Clara Turetta, Paolo Cristofanelli, Claudio Scarchilli, Olivier Magand, Paolo Grigioni, Virginia Ciardini, Beatriz Ferreira Araujo, Francesca Sprovieri, Niccolò Maffezzoli, Warren Rl. Cairns, Delia Segato, Andrea Spolaor, Carlo Barbante, Aurélien Dommergue, Hélène Angot, Cairns, W. R., Turetta, C., Maffezzoli, N., Magand, O., Araujo, B. F., Angot, H., Segato, D., Cristofanelli, P., Sprovieri, F., Scarchilli, C., Grigioni, P., Ciardini, V., Barbante, C., Dommergue, A., and Spolaor, A.
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Atmospheric Science ,High resolution sampling ,chemistry.chemical_element ,Snowpack ,Atmospheric sciences ,Snow ,Mercury (element) ,Snow scavenging factor ,Atmosphere ,Deposition (aerosol physics) ,Flux (metallurgy) ,chemistry ,Environmental science ,Atmospheric conditions ,Settore CHIM/01 - Chimica Analitica ,Snow sublimation ,Mercury cycle ,Scavenging ,General Environmental Science - Abstract
The role of deposition fluxes on the mercury cycle at Concordia station, on the high Antarctic plateau have been investigated over the Austral summer between December 2017 to January 2018. Wet/frozen deposition was collected daily from specially sited tables, simultaneously with the collection of surface (0-3 cm) and subsurface (3-6 cm) snow and the analysis of Hg-0 in the ambient air. Over the course of the experiment the atmospheric Hg-0 concentrations ranged from 0.58 +/- 0.19 to 1.00 +/- 0.33 ng m(-3), surface snow Hg concentrations varied between (0-3 cm) 0.006 +/- 0.003 to 0.001 +/- 0.001 ng cm(-3) and subsurface snow (3-6 cm) concentrations varied between 0.001 +/- 0.001 to 0.003 +/- 0.002 ng cm(-3). The maximum daily wet deposition flux was found to be 23 ng m(-2) d(-)(1). Despite the low temporal resolution of our measurements combined with their potential errors, the linear regression of the Hg deposition fluxes against the snow accumulation rates allowed us to estimate the mean dry deposition rate from the intercept of the graph as -0.005 +- 0.008 ng m(-2) d(-1). From this analysis, we conclude that wet deposition accounts for the vast majority of the Hg deposition fluxes at Concordia Station. The number of snow events, together with the continuous GEM measurements have allowed us to make a first estimation of the mean snow scavenging factor at Dome C. Using the slope of the regression of mercury flux on snow accumulation we obtained a snow scavenging factor that ranges from 0.21 to 0.22 +/- 0.02 (ng(Hg)/g (snow))/(ng(Hg)/m(3) (air)). Our data indicate that the boundary layer height and local meteorological effects influence Hg-0 reemission from the top of (0-3 cm) the snowpack into the atmosphere and into the deeper snowpack layer (3-6 cm). These data will help constrain numerical models on the behaviour of mercury in Antarctica.
- Published
- 2021
35. Impact of dam flushing operations on sediment dynamics and quality in the upper Rhône River, France
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Hugo Lepage, Olivier Radakovitch, M. Launay, Marina Coquery, Jérôme Le Coz, Hélène Angot, Stéphanie Gairoard, Cecile Miege, PSE-ENV/SRTE/LRTA, Institut de Radioprotection et de Sûreté Nucléaire (IRSN), UR Hydrologie-Hydraulique, Institut de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA), UR Riverly, Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA), University of Colorado [Boulder], CEREGE, Centre national de la recherche scientifique, Université Aix-Marseille, Institut de recherche pour le développement (CNRS, AMU, IRD), Laboratoire de recherche sur les transferts des radionucléides dans les écosystèmes aquatiques (IRSN/PSE-ENV/SRTE/LRTA), Service de recherche sur les transferts et les effets des radionucléides sur les écosystèmes (IRSN/PSE-ENV/SRTE), Institut de Radioprotection et de Sûreté Nucléaire (IRSN)-Institut de Radioprotection et de Sûreté Nucléaire (IRSN), RiverLy - Fonctionnement des hydrosystèmes (RiverLy), Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE), Centre européen de recherche et d'enseignement des géosciences de l'environnement (CEREGE), Institut de Recherche pour le Développement (IRD)-Aix Marseille Université (AMU)-Collège de France (CdF (institution))-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE), ANR-11-LABX-0010,DRIIHM / IRDHEI,Dispositif de recherche interdisciplinaire sur les Interactions Hommes-Milieux(2011), and Riverly (Riverly)
- Subjects
Geologic Sediments ,Environmental Engineering ,0208 environmental biotechnology ,02 engineering and technology ,010501 environmental sciences ,Management, Monitoring, Policy and Law ,01 natural sciences ,Flux (metallurgy) ,Rivers ,medicine ,Trace metal ,Polycyclic Aromatic Hydrocarbons ,Waste Management and Disposal ,0105 earth and related environmental sciences ,Hydrology ,Baseflow ,Flood myth ,OBSERVATOIRE OSR ,Sediment ,General Medicine ,Contamination ,Particulates ,6. Clean water ,020801 environmental engineering ,13. Climate action ,[SDE]Environmental Sciences ,Environmental science ,Flushing ,France ,ZABR ,medicine.symptom ,Water Pollutants, Chemical ,Environmental Monitoring - Abstract
The Rhone River (France) has been used for energy production for decades and 21 dams have been built. To avoid problems due to sediment storage, dam flushing operations are periodically organized. The impacts of such operations on suspended particulate matter (SPM) dynamics (resuspension and fluxes) and quality (physico-chemical characteristics and contamination), were investigated during a flushing operation performed in June 2012 on 3 major dams from the Upper Rhone River. The concentrations of major hydrophobic organic contaminants (polychlorinated biphenyls, polycyclic aromatic hydrocarbons - PAHs, bis(2-ethylhexyl)phthalate [DEHP] and 4-n-nonylphenol), trace metal elements, particulate organic carbon (POC) and particle size distribution were measured on SPM samples collected during this event as well as on those obtained from 2011 to 2016 at a permanent monitoring station (150 km downstream). This allows to compare the SPM and contaminant concentrations and fluxes during the 2012 dam flushing operations with those during flood events and baseflow regime. At equal water discharge, mean SPM concentrations during flushing were on average 6–8 times higher than during flood events recorded from 2011 to 2016. While of short duration (19 days), the flushing operations led to the resuspension of SPM and contributed to a third of the mean annual SPM flux. The SPM contamination was generally lower during flushing than during baseflow or flood, probably due to the fact that flushing transports SPM only issued from resuspended sediment, with no autochtonous particles nor eroded soil. The only exception are PAHs and DEHP with higher concentrations during flushing, which must be issued from the resuspension of legacy-contaminated sediments stored behind the dams before the implementation of emission regulations. During flushing, the variations of POC and contaminant concentrations are also mostly driven by particle size. Finally, we propose a list of recommendations for the design of an adequate monitoring network to evaluate the impact of dam flushing operations on large river systems.
- Published
- 2019
36. Diurnal cycle of iodine and mercury concentrations in Svalbard surface snow
- Author
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Andrea Spolaor, Elena Barbaro, David Cappelletti, Clara Turetta, Mauro Mazzola, Fabio Giardi, Mats P. Björkman, Federico Lucchetta, Federico Dallo, Katrine Aspmo Pfaffhuber, Hélène Angot, Aurelien Dommergue, Marion Maturilli, Alfonso Saiz-Lopez, Carlo Barbante, and Warren R. L. Cairns
- Abstract
Sunlit snow is highly photochemically active and plays an important role in the exchange of gas-phase species between the cryosphere to the atmosphere. Here, we investigate the behaviour of two selected species in surface snow: mercury (Hg) and iodine (I). Hg can deposit year-round and accumulate in the snowpack. However, photo-induced re-emission of gas phase Hg from the surface has been widely reported. Iodine is active in atmosphere new particle formation, especially in the marine boundary layer, and in the destruction of atmospheric ozone. It can also undergo photochemical re-emission. Although previous studies indicate possible post-depositional processes, little is known about the diurnal behaviour of these two species and their interaction in surface snow. The mechanisms are still poorly constrained and no field experiments have been performed in different seasons to investigate the magnitude of re-emission processes. Three high temporal resolution (hourly samples) 3 days long sampling campaign were carried out near Ny-Ålesund (Svalbard) to study the behaviour of mercury and iodine in surface snow under different sunlight and environmental conditions (24 h-darkness, 24 h-sunlight and day/night cycles). Our results indicate a clearly different behaviour of Hg and I in surface snow during the different campaign. The day/night experiments demonstrate the existence of a diurnal cycle in surface snow for Hg and iodine, indicating that these species are indeed influenced by the daily solar radiation cycle. Differently bromine did not show any diurnal cycle. The diurnal cycle disappeared also for Hg and iodine during the 24 h-sunlight period and during 24 h-darkness experiments supporting the idea of the occurrence (absence) of a continuous recycling/exchange at the snow-air interface. These results demonstrate that this surface snow recycling is seasonally dependent, through sunlight. They also highlight the non-negligible role that snowpack emissions have on ambient air concentrations and potentially on iodine-induced atmospheric nucleation processes.
- Published
- 2019
37. Global and local impacts of delayed mercury mitigation efforts
- Author
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Hélène Angot, Noel R. Urban, Noelle E. Selin, Amanda Giang, Colin P. Thackray, Nicholas Hoffman, and Ashley N. Hendricks
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010504 meteorology & atmospheric sciences ,Extramural ,Fishes ,chemistry.chemical_element ,General Chemistry ,Limiting ,Mercury ,010501 environmental sciences ,01 natural sciences ,Article ,Mercury (element) ,Lakes ,chemistry ,Environmental protection ,Environmental monitoring ,Environmental Chemistry ,Environmental science ,Animals ,Ecosystem ,0105 earth and related environmental sciences ,Mercury deposition ,Environmental Monitoring - Abstract
Mercury (Hg) is emitted to air by natural and anthropogenic sources, transports and deposits globally, and bioaccumulates to toxic levels in food webs. It is addressed under the global 2017 Minamata Convention, for which periodic effectiveness evaluation is required. Previous analyses have estimated the impact of different regulatory strategies for future mercury deposition. However, analyses using atmospheric models traditionally hold legacy emissions (recycling of previously deposited Hg) constant, and do not account for their possible future growth. Here, using an integrated modeling approach, we investigate how delays in implementing emissions reductions and the associated growing legacy reservoir affect deposition fluxes to ecosystems in different global regions. Assuming nearly constant yearly emissions relative to 2010, each 5-year delay in peak emissions defers by additional extra ca. 4 years the return to year 2010 global deposition. On a global average, each 5-year delay leads to a 14% decrease in policy impacts on local-scale Hg deposition. We also investigate the response of fish contamination in remote lakes to delayed action. We quantify the consequences of delay for limiting the Hg burden of future generations and show that traditional analyses of policy impacts provide best-case estimates.
- Published
- 2018
38. Multi-year record of atmospheric mercury at Dumont d'Urville, East Antarctic coast: continental outflow and oceanic influences
- Author
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Michel Legrand, Olivier Magand, Hélène Angot, Iris Dion, Aurélien Dommergue, Nicolas Vogel, Laboratoire de glaciologie et géophysique de l'environnement (LGGE), Observatoire des Sciences de l'Univers de Grenoble (OSUG), Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA)-Centre National de la Recherche Scientifique (CNRS), Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Observatoire des Sciences de l'Univers de Grenoble (OSUG ), Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut national des sciences de l'Univers (INSU - CNRS)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019]), Observatoire des Sciences de l'Univers de Grenoble (OSUG ), and Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut national des sciences de l'Univers (INSU - CNRS)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut national des sciences de l'Univers (INSU - CNRS)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Centre National de la Recherche Scientifique (CNRS)
- Subjects
[SDU.OCEAN]Sciences of the Universe [physics]/Ocean, Atmosphere ,[PHYS.PHYS.PHYS-AO-PH]Physics [physics]/Physics [physics]/Atmospheric and Oceanic Physics [physics.ao-ph] ,Atmospheric Science ,Katabatic wind ,010504 meteorology & atmospheric sciences ,chemistry.chemical_element ,Pelagic zone ,010501 environmental sciences ,Snow ,01 natural sciences ,lcsh:QC1-999 ,Latitude ,Mercury (element) ,lcsh:Chemistry ,Oceanography ,chemistry ,lcsh:QD1-999 ,13. Climate action ,Environmental science ,Ecosystem ,Outflow ,14. Life underwater ,Sea level ,lcsh:Physics ,0105 earth and related environmental sciences - Abstract
Under the framework of the Global Mercury Observation System (GMOS) project, a 3.5-year record of atmospheric gaseous elemental mercury (Hg(0)) has been gathered at Dumont d'Urville (DDU, 66°40′ S, 140°01′ E, 43 m above sea level) on the East Antarctic coast. Additionally, surface snow samples were collected in February 2009 during a traverse between Concordia Station located on the East Antarctic plateau and DDU. The record of atmospheric Hg(0) at DDU reveals particularities that are not seen at other coastal sites: a gradual decrease of concentrations over the course of winter, and a daily maximum concentration around midday in summer. Additionally, total mercury concentrations in surface snow samples were particularly elevated near DDU (up to 194.4 ng L−1) as compared to measurements at other coastal Antarctic sites. These differences can be explained by the more frequent arrival of inland air masses at DDU than at other coastal sites. This confirms the influence of processes observed on the Antarctic plateau on the cycle of atmospheric mercury at a continental scale, especially in areas subject to recurrent katabatic winds. DDU is also influenced by oceanic air masses and our data suggest that the ocean plays a dual role on Hg(0) concentrations. The open ocean may represent a source of atmospheric Hg(0) in summer whereas the sea-ice surface may provide reactive halogens in spring that can oxidize Hg(0). This paper also discusses implications for coastal Antarctic ecosystems and for the cycle of atmospheric mercury in high southern latitudes.
- Published
- 2016
39. Supplementary material to 'Understanding mercury oxidation and air-snow exchange on the East Antarctic Plateau: A modeling study'
- Author
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Shaojie Song, Hélène Angot, Noelle E. Selin, Hubert Gallée, Francesca Sprovieri, Nicola Pirrone, Detlev Helmig, Joël Savarino, Olivier Magand, and Aurélien Dommergue
- Published
- 2018
40. Tracing the Fate of Atmospheric Nitrate in a Subalpine Watershed Using Δ
- Author
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Ilann, Bourgeois, Joël, Savarino, Nicolas, Caillon, Hélène, Angot, Albane, Barbero, Franck, Delbart, Didier, Voisin, and Jean-Christophe, Clément
- Subjects
Nitrates ,Rivers ,Nitrogen ,Prospective Studies ,Ecosystem ,Environmental Monitoring - Abstract
Nitrogen is an essential nutrient for life on Earth, but in excess, it can lead to environmental issues (e.g., N saturation, loss of biodiversity, acidification of lakes, etc.). Understanding the nitrogen budget (i.e., inputs and outputs) is essential to evaluate the prospective decay of the ecosystem services (e.g., freshwater quality, erosion control, loss of high patrimonial-value plant species, etc.) that subalpine headwater catchments provide, especially as these ecosystems experience high atmospheric nitrogen deposition. Here, we use a multi-isotopic tracer (Δ
- Published
- 2018
41. Sampling of suspended particulate matter using particle traps in the Rhône River: Relevance and representativeness for the monitoring of contaminants
- Author
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M. Masson, Aymeric Dabrin, J. Le Coz, M. Launay, Marina Coquery, Cecile Miege, C. Le Bescond, Hélène Angot, RiverLy (UR Riverly), and Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)
- Subjects
Pollution ,sampling ,suspended matter ,Environmental Engineering ,ECHANTILLONNAGE ,010504 meteorology & atmospheric sciences ,media_common.quotation_subject ,chemistry.chemical_element ,Fresh Water ,010501 environmental sciences ,01 natural sciences ,Water column ,contamination ,Rivers ,Environmental Chemistry ,Water Pollutants ,Organic matter ,Waste Management and Disposal ,0105 earth and related environmental sciences ,media_common ,organic matter ,chemistry.chemical_classification ,Total organic carbon ,[SDE.IE]Environmental Sciences/Environmental Engineering ,MATIERE ORGANIQUE ,Particulates ,Contamination ,Polychlorinated Biphenyls ,Carbon ,6. Clean water ,Mercury (element) ,chemistry ,MATIERES EN SUSPENSION ,13. Climate action ,Environmental chemistry ,Particle-size distribution ,Environmental science ,Particulate Matter ,Water Pollutants, Chemical ,Environmental Monitoring - Abstract
International audience; Monitoring hydrophobic contaminants in surface freshwaters requires measuring contaminant concentrations in the particulate fraction (sediment or suspended particulate matter, SPM) of the water column. Particle traps (PTs) have been recently developed to sample SPM as cost-efficient, easy to operate and time-integrative tools. But the representativeness of SPM collected with PTs is not fully understood, notably in terms of grain size distribution and particulate organic carbon (POC) content, which could both skew particulate contaminant concentrations. The aim of this study was to evaluate the representativeness of SPM characteristics (i.e. grain size distribution and POC content) and associated contaminants (i.e. polychlorinated biphenyls, PCBs; mercury, Hg) in samples collected in a large river using PTs for differing hydrological conditions. Samples collected using PTs (n = 74) were compared with samples collected during the same time period by continuous flow centrifugation (CFC). The grain size distribution of PT samples shifted with increasing water discharge: the proportion of very fine silts (2-6 µm) decreased while that of coarse silts (27-74 µm) increased. Regardless of water discharge, POC contents were different likely due to integration by PT of high POC-content phytoplankton blooms or low POC-content flood events. Differences in PCBs and Hg concentrations were usually within the range of analytical uncertainties and could not be related to grain size or POC content shifts. Occasional Hg-enriched inputs may have led to higher Hg concentrations in a few PT samples (n = 4) which highlights the time-integrative capacity of the PTs. The differences of annual Hg and PCB fluxes calculated either from PT samples or CFC samples were generally below 20%. Despite some inherent limitations (e.g. grain size distribution bias), our findings suggest that PT sampling is a valuable technique to assess reliable spatial and temporal trends of particulate contaminants such as PCBs and Hg within a river monitoring network.
- Published
- 2018
42. Characterizing Atmospheric Transport Pathways to Antarctica and the Remote Southern Ocean using Radon-222
- Author
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Ian E. Galbally, Sang-Bum Hong, Alan D. Griffiths, Zoe Loh, Alastair G. Williams, Scott D. Chambers, Jack B Simmons, Paul B. Krummel, Taejin Choi, Ruhi S Humphries, Suzie B. Molloy, Michel Legrand, Jagoda Crawford, Francesca Sprovieri, Hélène Angot, Aurélien Dommergue, Susanne Preunkert, Stephen R. Wilson, Olivier Magand, Rolf Weller, Nicola Pirrone, Laura Tositti, and Chambers S.D., Preunkert S, Weller R, Hong S.-B. , Humphries R.S ., Tositti L., Angot H., Legrand M., Williams A.G., Griffiths A.D., Crawford J., Simmons J., Choi T.J., . Krummel P.B., Molloy S., Loh Z., Galbally I., Wilson S., Magand O., Sprovieri F., Pirrone N. and Dommergue A.
- Subjects
Katabatic wind ,Radon-222, Antarctica, Planetary Boundary Layer ,010504 meteorology & atmospheric sciences ,atmospheric transport ,Antarctic ice sheet ,chemistry.chemical_element ,Radon ,MBL ,010501 environmental sciences ,Atmospheric sciences ,01 natural sciences ,Troposphere ,medicine ,14. Life underwater ,Southern Ocean ,lcsh:Science ,0105 earth and related environmental sciences ,Polar front ,radon ,Seasonality ,medicine.disease ,Trace gas ,chemistry ,troposphere ,13. Climate action ,General Earth and Planetary Sciences ,Environmental science ,Antarctica ,Outflow ,lcsh:Q - Abstract
We discuss remote terrestrial influences on boundary layer air over the Southern Ocean and Antarctica, and the mechanisms by which they arise, using atmospheric radon observations as a proxy. Our primary motivation was to enhance the scientific community’s ability to understand and quantify the potential effects of pollution, nutrient or pollen transport from distant land masses to these remote, sparsely instrumented regions. Seasonal radon characteristics are discussed at 6 stations (Macquarie Island, King Sejong, Neumayer, Dumont d’Urville, Jang Bogo and Dome Concordia) using 1–4 years of continuous observations. Context is provided for differences observed between these sites by Southern Ocean radon transects between 45 and 67°S made by the Research Vessel Investigator. Synoptic transport of continental air within the marine boundary layer (MBL) dominated radon seasonal cycles in the mid-Southern Ocean site (Macquarie Island). MBL synoptic transport, tropospheric injection, and Antarctic outflow all contributed to the seasonal cycle at the sub-Antarctic site (King Sejong). Tropospheric subsidence and injection events delivered terrestrially influenced air to the Southern Ocean MBL in the vicinity of the circumpolar trough (or “Polar Front”). Katabatic outflow events from Antarctica were observed to modify trace gas and aerosol characteristics of the MBL 100–200 km off the coast. Radon seasonal cycles at coastal Antarctic sites were dominated by a combination of local radon sources in summer and subsidence of terrestrially influenced tropospheric air, whereas those on the Antarctic Plateau were primarily controlled by tropospheric subsidence. Separate characterization of long-term marine and katabatic flow air masses at Dumont d’Urville revealed monthly mean differences in summer of up to 5 ppbv in ozone and 0.3 ng m-3 in gaseous elemental mercury. These differences were largely attributed to chemical processes on the Antarctic Plateau. A comparison of our observations with some Antarctic radon simulations by global climate models over the past two decades indicated that: (i) some models overestimate synoptic transport to Antarctica in the MBL, (ii) the seasonality of the Antarctic ice sheet needs to be better represented in models, (iii) coastal Antarctic radon sources need to be taken into account, and (iv) the underestimation of radon in subsiding tropospheric air needs to be investigated.
- Published
- 2018
43. The superstatistical nature and interoccurrence time of atmospheric mercury concentration fluctuations
- Author
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Antonio G. Bruno, Francesco Carbone, Aurélien Dommergue, Olivier Magand, Nicola Pirrone, Matthew S. Landis, Attilio Naccarato, Hélène Angot, Francesca Sprovieri, Katrine Aspmo Pfaffhuber, Katie A. Read, Christian N. Gencarelli, F. De Simone, Lynwill Martin, Ian M. Hedgecock, Henrik Skov, Institut des Géosciences de l’Environnement (IGE), Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP ), and Université Grenoble Alpes (UGA)
- Subjects
Atmospheric Science ,010504 meteorology & atmospheric sciences ,Atmospheric mercury ,universal scaling ,Data series ,Pollution: urban and regional ,heavy and fat-tailed ,01 natural sciences ,superstatistics ,atmospheric turbulence ,Zeppelinobservatoriet ,Earth and Planetary Sciences (miscellaneous) ,Statistical physics ,Physics ,Mesoscopic physics ,interoccurrence times ,Geophysics ,Statistical analysis ,Trollobservatoriet ,Superstatistics ,Exponential distribution ,mercury ,Andøyaobservatoriet ,Probability density function ,Article ,0103 physical sciences ,Scaling: spatial and temporal ,010306 general physics ,0105 earth and related environmental sciences ,Autocorrelation ,Function (mathematics) ,Turbulence ,Probability distributions ,Space and Planetary Science ,[SDU]Sciences of the Universe [physics] - Abstract
International audience; The probability density function (PDF) of the time intervals between subsequent extreme events in atmospheric Hg0 concentration data series from different latitudes has been investigated. The Hg0 dynamic possesses a long-term memory autocorrelation function. Above a fixed threshold Q in the data, the PDFs of the interoccurrence time of the Hg0 data are well described by a Tsallis q-exponential function. This PDF behavior has been explained in the framework of superstatistics, where the competition between multiple mesoscopic processes affects the macroscopic dynamics. An extensive parameter μ, encompassing all possible fluctuations related to mesoscopic phenomena, has been identified. It follows a χ2 distribution, indicative of the superstatistical nature of the overall process. Shuffling the data series destroys the long-term memory, the distributions become independent of Q, and the PDFs collapse on to the same exponential distribution. The possible central role of atmospheric turbulence on extreme events in the Hg0 data is highlighted.
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- 2018
44. Feedback mechanisms between snow and atmospheric mercury: Results and observations from field campaigns on the Antarctic plateau
- Author
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Hélène Angot, Francesca Sprovieri, Claudio Scarchilli, Andrea Spolaor, Carlo Barbante, Olivier Magand, Warren R. L. Cairns, Aurélien Dommergue, Cristiano Varin, Massimo Del Guasta, Michel Legrand, Xanthi Pedeli, Marco Roman, Massimiliano Vardè, and Scarchilli, C.
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Environmental Engineering ,010504 meteorology & atmospheric sciences ,Health, Toxicology and Mutagenesis ,Antartica ,Antarctic Regions ,Atmospheric mercury ,chemistry.chemical_element ,Mercury, Antarctica, Dome C, Halogens, Precipitation, Snow ,Precipitation ,010501 environmental sciences ,Surface concentration ,Atmospheric sciences ,01 natural sciences ,Geochemical cycle ,Halogens ,Snow ,Environmental Chemistry ,Settore CHIM/01 - Chimica Analitica ,Saline Waters ,0105 earth and related environmental sciences ,Dome C ,Air Pollutants ,photochemistry ,Atmosphere ,Public Health, Environmental and Occupational Health ,Concordia Station ,General Medicine ,General Chemistry ,Mercury ,Snowpack ,Pollution ,Mercury (element) ,chemistry ,Halogen ,Environmental science ,Antarctica ,Seasons ,human activities ,Environmental Monitoring ,Mercury deposition ,Antarctic plateau - Abstract
The Antarctic Plateau snowpack is an important environment for the mercury geochemical cycle. We have extensively characterized and compared the changes in surface snow and atmospheric mercury concentrations that occur at Dome C. Three summer sampling campaigns were conducted between 2013 and 2016. The three campaigns had different meteorological conditions that significantly affected mercury deposition processes and its abundance in surface snow. In the absence of snow deposition events, the surface mercury concentration remained stable with narrow oscillations, while an increase in precipitation results in a higher mercury variability. The Hg concentrations detected confirm that snowfall can act as a mercury atmospheric scavenger. A high temporal resolution sampling experiment showed that surface concentration changes are connected with the diurnal solar radiation cycle. Mercury in surface snow is highly dynamic and it could decrease by up to 90% within 4/6 h. A negative relationship between surface snow mercury and atmospheric concentrations has been detected suggesting a mutual dynamic exchange between these two environments. Mercury concentrations were also compared with the Br concentrations in surface and deeper snow, results suggest that Br could have an active role in Hg deposition, particularly when air masses are from coastal areas. This research presents new information on the presence of Hg in surface and deeper snow layers, improving our understanding of atmospheric Hg deposition to the snow surface and the possible role of re-emission on the atmospheric Hg concentration. © 2018 Elsevier Ltd
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- 2018
45. Top-down constraints on atmospheric mercury emissions and implications for global biogeochemical cycling
- Author
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Peter Weiss-Penzias, Aurélien Dommergue, Dennis Wip, Shichang Kang, Olivier Magand, Guey Rong Sheu, Noelle E. Selin, Ernst Günther Brunke, Paul Kelley, Winston T. Luke, Steven Brooks, Katrine Aspmo Pfaffhuber, Hélène Angot, Thorsten Warneke, Shaoije Song, Kohji Marumoto, Anne L. Soerensen, Richard S. Artz, Xinrong Ren, Thomas M. Holsen, Qianggong Zhang, Andreas Weigelt, Gary D. Conley, Franz Slemr, Ralf Ebinghaus, Daniel A. Jaffe, Massachusetts Institute of Technology. Department of Earth, Atmospheric, and Planetary Sciences, Massachusetts Institute of Technology. Engineering Systems Division, Song, Shaojie, Selin, Noelle Eckley, Department of Earth, Atmospheric and Planetary Sciences [MIT, Cambridge] (EAPS), Massachusetts Institute of Technology (MIT), Harvard School of Public Health, Stockholm University, Laboratoire de glaciologie et géophysique de l'environnement (LGGE), Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire des Sciences de l'Univers de Grenoble (OSUG), Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut national des sciences de l'Univers (INSU - CNRS)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS), NOAA Air Resources Laboratory (ARL), National Oceanic and Atmospheric Administration (NOAA), Department of Mechanical, Aerospace and Biomedical Engineering, University of Tennessee Space Institute (UTSI), South African Weather Service (SAWS), Ohio University, GKSS-Forschungszentrum Geesthacht GmbH, Institute for Coastal Research, Clarkson University, University of Washington-Bothell, Chinese Academy of Sciences [Beijing] (CAS), National Institute for Minamata Disease, Norwegian Institute for Air Research (NILU), University of Maryland [College Park], University of Maryland System, National Taiwan University [Taiwan] (NTU), Max-Planck-Institut für Chemie (MPIC), Max-Planck-Gesellschaft, Institute of Environmental Physics [Bremen] (IUP), University of Bremen, University of California [Santa Cruz] (UCSC), University of California, Anton de Kom Universiteit van Suriname - Anton de Kom University of Suriname [Paramaribo] (UVS), Institute of Tibetan Plateau Research, Chinese of Academy of Sciences, Observatoire des Sciences de l'Univers de Grenoble (OSUG), and Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA)-Centre National de la Recherche Scientifique (CNRS)
- Subjects
Atmospheric Science ,Biogeochemical cycle ,010504 meteorology & atmospheric sciences ,Chemical transport model ,Mixed layer ,Atmospheric mercury ,chemistry.chemical_element ,010501 environmental sciences ,Atmospheric sciences ,01 natural sciences ,Sink (geography) ,lcsh:Chemistry ,Zeppelinobservatoriet ,ddc:551 ,14. Life underwater ,0105 earth and related environmental sciences ,geography ,geography.geographical_feature_category ,Chemistry ,Inversion (meteorology) ,15. Life on land ,lcsh:QC1-999 ,Mercury (element) ,lcsh:QD1-999 ,13. Climate action ,Climatology ,[SDE]Environmental Sciences ,Terrestrial ecosystem ,Trollobservatoriet ,lcsh:Physics - Abstract
We perform global-scale inverse modeling to constrain present-day atmospheric mercury emissions and relevant physiochemical parameters in the GEOS-Chem chemical transport model. We use Bayesian inversion methods combining simulations with GEOS-Chem and ground-based Hg[superscript 0] observations from regional monitoring networks and individual sites in recent years. Using optimized emissions/parameters, GEOS-Chem better reproduces these ground-based observations and also matches regional over-water Hg[superscript 0] and wet deposition measurements. The optimized global mercury emission to the atmosphere is ~ 5.8 Gg yr[superscript −1]. The ocean accounts for 3.2 Gg yr[superscript −1] (55% of the total), and the terrestrial ecosystem is neither a net source nor a net sink of Hg[superscript 0]. The optimized Asian anthropogenic emission of Hg[superscript 0] (gas elemental mercury) is 650–1770 Mg yr[superscript −1], higher than its bottom-up estimates (550–800 Mg yr[superscript −1]). The ocean parameter inversions suggest that dark oxidation of aqueous elemental mercury is faster, and less mercury is removed from the mixed layer through particle sinking, when compared with current simulations. Parameter changes affect the simulated global ocean mercury budget, particularly mass exchange between the mixed layer and subsurface waters. Based on our inversion results, we re-evaluate the long-term global biogeochemical cycle of mercury, and show that legacy mercury becomes more likely to reside in the terrestrial ecosystem than in the ocean. We estimate that primary anthropogenic mercury contributes up to 23 % of present-day atmospheric deposition., National Science Foundation (U.S.). Atmospheric Chemistry Program (1053648)
- Published
- 2015
46. Calibrating pollutant dispersion in 1-D hydraulic models of river networks
- Author
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Jean-Baptiste Faure, Hélène Angot, M. Launay, Marina Coquery, J. Le Coz, Guillaume Dramais, C. Walter, Benoît Camenen, Hydrologie-Hydraulique (UR HHLY), Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA), and Milieux aquatiques, écologie et pollutions (UR MALY)
- Subjects
Environmental Engineering ,Hydraulics ,Soil science ,Management, Monitoring, Policy and Law ,law.invention ,DISPERSION ,POLLUTION ,MODELE HYDRAULIQUE ,law ,TRACER ,Dispersion (optics) ,Calibration ,Environmental Chemistry ,Geotechnical engineering ,Shear velocity ,ACOUSTIC DOPPLER CURRENT PROFILER ,Water Science and Technology ,Civil and Structural Engineering ,Mathematical model ,Computer simulation ,6. Clean water ,Moment (mathematics) ,COURS D'EAU ,13. Climate action ,[SDE]Environmental Sciences ,Environmental science - Abstract
International audience; The objective of this article is to investigate the major issues associated with the calibration of the pollutant dispersion in 1-D hydraulic models applied to river networks, especially large, complex, artificializedones where ecological and socio-economical threats are important. Such issues are illustrated and discussedusing the results of five fluorescent tracer experiments conducted in contrasted open-channel systems,ranging from a simple trapezoidal canal to a more complex river network. Experimental dispersion values were quantified using both the change of moment method and a simple fit-by-eye procedure for eight river reaches with homogeneous hydraulic conditions and an achieved tracer mixing and dispersive equilibrium. Since dispersion coefficient values depend on the assumed dispersion model, ideally they should be calibrated using the same model in which they are to be used, as was done in this study. Wealso derived concurrent longitudinal dispersion values using the velocity field measured by hydro-acoustic profilers (ADCP), which appears as a promising and cost-efficient technique for documenting dispersion in large river systems. It appears that the formulae for which the fit was mainly based on the cross-sectional aspect ratio are generally more appropriate for field data than those which are sensitive to the velocity to shear velocity ratio. The interpretation of complex dispersion and mixing processes, along with the selection of relevant dispersion coefficient predictors are key to minimizing errors in the numerical simulation of pollution dynamics in river networks.
- Published
- 2015
47. Five-year records of mercury wet deposition flux at GMOS sites in the Northern and Southern hemispheres
- Author
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Katarina Hansson, María del Carmen Diéguez, Francesca Sprovieri, Francesco D'Amore, Xuewu Fu, Mariantonia Bencardino, Aurélien Dommergue, Carlo Barbante, Ralf Ebinghaus, Martha Ramirez Islas, X. Feng, Andreas Weigelt, Vladimir Obolkin, Hui Zhang, Xu Yang, Hélène Angot, Ulla Hageström, John Munthe, Lynwill Martin, Sara Comero, Milena Horvat, Vernon Somerset, Olivier Magand, Warren R. L. Cairns, Nicola Pirrone, Pia Spandow, Ingvar Wängberg, Flor Arcega-Cabrera, Nikolay Mashyanov, Bernd Manfred Gawlik, Patricia Elizabeth Garcia, Chavon R Walters, E.-G. Brunke, Casper Labuschagne, Jože Kotnik, Thumeka Mkololo, Fabrizio Sena, Massimiliano Vardè, Institut des Géosciences de l’Environnement (IGE), and Institut de Recherche pour le Développement (IRD)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])
- Subjects
Atmospheric Science ,010504 meteorology & atmospheric sciences ,chemistry.chemical_element ,010501 environmental sciences ,Northern and Southern Hemisphere ,Atmospheric sciences ,01 natural sciences ,lcsh:Chemistry ,Sedimentary depositional environment ,Mercury wet deposition flux ,Settore CHIM/01 - Chimica Analitica ,Southern Hemisphere ,Scavenging ,0105 earth and related environmental sciences ,spatial and seasonal trends ,lcsh:QC1-999 ,Mercury (element) ,Deposition (aerosol physics) ,lcsh:QD1-999 ,chemistry ,[SDU]Sciences of the Universe [physics] ,13. Climate action ,Environmental chemistry ,Environmental science ,Cycling ,lcsh:Physics - Abstract
The atmospheric deposition of mercury (Hg) occurs via several mechanisms, including dry and wet scavenging by precipitation events. In an effort to understand the atmospheric cycling and seasonal depositional characteristics of Hg, wet deposition samples were collected for approximately 5 years at 17 selected GMOS monitoring sites located in the Northern and Southern hemispheres in the framework of the Global Mercury Observation System (GMOS) project. Total mercury (THg) exhibited annual and seasonal patterns in Hg wet deposition samples. Interannual differences in total wet deposition are mostly linked with precipitation volume, with the greatest deposition flux occurring in the wettest years. This data set provides a new insight into baseline concentrations of THg concentrations in precipitation worldwide, particularly in regions such as the Southern Hemisphere and tropical areas where wet deposition as well as atmospheric Hg species were not investigated before, opening the way for future and additional simultaneous measurements across the GMOS network as well as new findings in future modeling studies.
- Published
- 2017
48. Multi-model study of mercury dispersion in the atmosphere: Atmospheric processes and model evaluation
- Author
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Nikolay Mashyanov, Olivier Magand, Nicola Pirrone, Ralf Ebinghaus, Shaojie Song, Francesco De Simone, Ramesh Ramachandran, Aurélien Dommergue, Francesca Sprovieri, Katie A. Read, Volker Matthias, Johannes Bieser, Andrei Ryjkov, Dennis Wip, Oleg Travnikov, Noelle E. Selin, Hélène Angot, X. Feng, Mariantonia Bencardino, Ashu Dastoor, Ingvar Wängberg, Francesco D'Amore, Xin Yang, María del Carmen Diéguez, Lynwill Martin, Paulo Artaxo, Christian N. Gencarelli, Fabrizio Sena, Ian M. Hedgecock, Institut des Géosciences de l’Environnement (IGE), Institut de Recherche pour le Développement (IRD)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019]), Massachusetts Institute of Technology. Department of Earth, Atmospheric, and Planetary Sciences, Selin, Noelle E, and Song, Shaojie
- Subjects
Atmospheric Science ,010504 meteorology & atmospheric sciences ,GEOS-Chem ,chemistry.chemical_element ,010501 environmental sciences ,reactive Hg ,Spatial distribution ,Redox ,GLEMOS model ,01 natural sciences ,Ciencias de la Tierra y relacionadas con el Medio Ambiente ,purl.org/becyt/ford/1 [https] ,lcsh:Chemistry ,purl.org/becyt/ford/1.5 [https] ,Complex chemistry ,medicine ,ECHMERIT ,GEM-MACH-Hg model ,Hg wet deposition flux ,0105 earth and related environmental sciences ,Transport Models ,Model study ,Mercury Chemistry ,Northern Hemisphere ,Multi-model ,Seasonality ,medicine.disease ,gaseous elemental Hg ,ATMOSPHERE ,TRENDS ,lcsh:QC1-999 ,GLOBAL CIRCULATION MODELS ,Mercury (element) ,chemistry ,lcsh:QD1-999 ,[SDU]Sciences of the Universe [physics] ,13. Climate action ,Atmospheric chemistry ,Environmental chemistry ,MERCURY ,Meteorología y Ciencias Atmosféricas ,lcsh:Physics ,CIENCIAS NATURALES Y EXACTAS - Abstract
Current understanding of mercury (Hg) behaviour in the atmosphere contains significant gaps. Some key characteristics of Hg processes including anthropogenic and geogenic emissions, atmospheric chemistry, and air-surface exchange are still poorly known. This study provides a complex analysis of processes governing Hg fate in the atmosphere involving both measurement5 data from ground-based sites and simulation results of chemical transport models. A variety of long-term measurements of gaseous elemental Hg (GEM) and reactive Hg (RM) concentration as well as Hg wet deposition flux has been compiled from different global and regional monitoring networks. Four contemporary global-scale transport models for Hg were applied both in their state-of-the-art configurations and for a number of numerical experiments aimed at evaluation of particular processes. Fil: Travnikov, Oleg. Meteorological Synthesizing Centre; Rusia Fil: Angot, Hélène. University Grenoble Alpes; Francia Fil: Artaxo, Paulo. Universidade de Sao Paulo; Brasil Fil: Bencardino, Mariantonia. Consiglio Nazionale delle Ricerche; Italia Fil: Bieser, Johannes. Institute of Coastal Research; Alemania Fil: D'Amore, Francesco. Consiglio Nazionale delle Ricerche; Italia Fil: Dastoor, Ashu. Environment and Climate Change Canada; Canadá Fil: De Simone, Francesco. Consiglio Nazionale delle Ricerche; Italia Fil: Dieguez, Maria del Carmen. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte. Instituto de Investigaciones en Biodiversidad y Medioambiente. Universidad Nacional del Comahue. Centro Regional Universidad Bariloche. Instituto de Investigaciones en Biodiversidad y Medioambiente; Argentina Fil: Dommergue, Aurélien. University Grenoble Alpes; Francia. Laboratoire de Glaciologie et Géophysique de l’Environnement; Francia Fil: Ebinghaus, Ralf. Institute of Coastal Research; Alemania Fil: Feng, Xin Bin. Chinese Academy of Sciences; República de China Fil: Gencarelli, Christian N.. Consiglio Nazionale delle Ricerche; Italia Fil: Hedgecock, Ian M.. Consiglio Nazionale delle Ricerche; Italia Fil: Magand, Olivier. Laboratoire de Glaciologie et Géophysique de l’Environnement; Francia Fil: Martin, Lynwill. South African Weather Service; Sudáfrica Fil: Matthias, Volker. Institute of Coastal Research; Alemania Fil: Mashyanov, Nikolay. St. Petersburg State University; Rusia Fil: Pirrone, Nicola. Consiglio Nazionale delle Ricerche; Italia Fil: Ramachandran, Ramesh. Anna University; India Fil: Read, Katie Alana. University of York; Reino Unido Fil: Ryjkov, Andrei. Environment and Climate Change Canada; Canadá Fil: Selin, Noelle E.. Massachusetts Institute of Technology; Estados Unidos Fil: Sena, Fabrizio. Joint Research Centre; Italia Fil: Song, Shaojie. Massachusetts Institute of Technology; Estados Unidos Fil: Sprovieri, Francesca. Institute of Atmospheric Pollution Research; Italia Fil: Wip, Dennis. University of Suriname; Surinam Fil: Wängberg, Ingvar. Swedish Environmental Research Institute; Suecia Fil: Yang, Xin. British Antarctic Survey; Reino Unido
- Published
- 2017
49. Supplementary material to 'Multi-model study of mercury dispersion in the atmosphere: Atmospheric processes and model evaluation'
- Author
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Oleg Travnikov, Hélène Angot, Paulo Artaxo, Mariantonia Bencardino, Johannes Bieser, Francesco D’Amore, Ashu Dastoor, Francesco De Simone, María del Carmen Diéguez, Aurélien Dommergue, Ralf Ebinghaus, Xin Bin Feng, Christian N. Gencarelli, Ian M. Hedgecock, Olivier Magand, Lynwill Martin, Volker Matthias, Nikolay Mashyanov, Nicola Pirrone, Ramesh Ramachandran, Katie Alana Read, Andrei Ryjkov, Noelle E. Selin, Fabrizio Sena, Shaojie Song, Francesca Sprovieri, Dennis Wip, Ingvar Wängberg, and Xin Yang
- Published
- 2016
50. Wet deposition of Total Mercury: Concentration, Rainfall Depth and Fluxes in the Southern Indian Ocean at Amsterdam Island (38°S): GMOS project
- Author
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Massimiliano Vardè, Alessandro Servidio, Annalisa Rosselli, Franco Cofone, Francesca Sprovieri, Hélène Angot, Aurelien Dommergue, Olivier Magand, and Manuel Barret.
- Subjects
rainfall depth ,Amsterdam Island (FRA) ,wet deposition ,Total mercury ,Hg ,fluxes - Abstract
Mercury (Hg) is a toxic worldwide trace element which due to its volatility once emitted into the atmosphere from both natural and anthropogenic sources, is transported to long distance and transferred to aquatic and terrestrial receptors by wet and dry deposition. Amsterdam Island (AMS) hosts a French Scientific Base were in the framework of the Global Mercury Observation System (GMOS) project scientists performed for the first time measurements of mercury in ambient air and deposition. Rainfall depth and Total Mercury (THg) concentrations and fluxes in wet deposition were determined for all samples collected from March 2013 to December 2014 at this GMOS master site. Weekly, biweekly and monthly-based precipitation samples were collected using automated wet-only precipitation collection system. Samples were treated according to GMOS protocol and analyzed by cold vapor atomic fluorescence spectrometry (CVAFS). This report presents the results of THg concentrations in precipitation. THg concentration in wet deposition samples ranged from 0.6 ng L-1 to 4.6 ng L-1 (September 2013), and the rainfall depth values were 2.9 and 123.9 mm (April 2013). The volume-weighted mean (VWM) concentrations and annual wet deposition fluxes of THg in precipitation were 2.0 ng L-1 and 3.4 micro g m-2 yr-1 respectively. For the entire study THg flux has been estimated to be 5.4 ng m-2 d-1. Annual mean of THg concentrations in rainy samples obtained at Amsterdam Island site during this study was comparable to the mean values observed at rural and remote sites at different latitudes reported in scientific papers and project reports.
- Published
- 2016
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