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3. Investigating halogens and MSA in the Southern Hemisphere: A spatial analysis

Author

École Polytechnique Fédérale de Lausanne, Swiss Polar Institute, Ferring Pharmaceuticals, Natural Environment Research Council (UK), Programma Nazionale per la Ricerca in Antartide, Royal Society (UK), Segato, Delia [0000-0003-3375-3319], Thomas, Elizabeth R. [0000-0002-3010-6493], #NODATA#, Moser, Dorothea Elisabeth [0000-0001-9085-9713], Fernandez, Rafael P. [0000-0002-4114-5500], Spolaor, Andrea [0000-0001-8635-9193], Segato, Delia, Thomas, Elizabeth R., Tetzner, Dieter, Jackson, Sarah, Moser, Dorothea Elisabeth, Turetta, Clara, Fernandez, Rafael P., Saiz-Lopez, A., Pedro, Joel, Markle, Bradley, Spolaor, Andrea, École Polytechnique Fédérale de Lausanne, Swiss Polar Institute, Ferring Pharmaceuticals, Natural Environment Research Council (UK), Programma Nazionale per la Ricerca in Antartide, Royal Society (UK), Segato, Delia [0000-0003-3375-3319], Thomas, Elizabeth R. [0000-0002-3010-6493], #NODATA#, Moser, Dorothea Elisabeth [0000-0001-9085-9713], Fernandez, Rafael P. [0000-0002-4114-5500], Spolaor, Andrea [0000-0001-8635-9193], Segato, Delia, Thomas, Elizabeth R., Tetzner, Dieter, Jackson, Sarah, Moser, Dorothea Elisabeth, Turetta, Clara, Fernandez, Rafael P., Saiz-Lopez, A., Pedro, Joel, Markle, Bradley, and Spolaor, Andrea

Abstract

Sub-Antarctic islands and Antarctic coastal regions provide valuable sites for investigating environmental processes in the Southern Ocean. The fact that these sites are situated within the sea ice zone underscores their significance in investigating the impact of sea ice on the chemical composition of the boundary layer. In this study we report multi-year average levels of marine aerosols, including bromine, sodium, methanesulphonic acid and iodine, measured in five firn cores collected from sub-Antarctic Islands and coastal Antarctic sites. The records are compared with published Antarctic records to explore the spatial distribution of these species in the Antarctic region and their relationship with sea ice variability. Being mainly sourced from sea-salt aerosols, sodium and bromine exhibit the largest concentrations in the sub-Antarctic region, with progressively reduced deposition from the coast towards the central Antarctic plateau. Due to its gas-phase chemistry, bromine is depleted with respect to sodium in the sub-Antarctic sites. Bromine emitted in the form of sea-salt aerosols undergoes multi-phase recycling in the lower troposphere and, together with gas-phase bromine emitted from sea ice, is likely to be transported away from the source, depositing in enriched concentrations in the plateau compared to the Br/Na sea-water mass ratio. Similarly to bromine and sodium, methanesulphonic acid and iodine are found in higher concentrations in the sub-Antarctic sites, especially where the ocean is sea ice-covered during spring as primary production is stronger than in the ice-free ocean. Sea-salt mediated recycling of gas-phase iodine enhances its atmospheric lifetime, delivering enriched iodine depositions to the Antarctic plateau. Depicting the spatial distribution of these elements is of great importance for understanding the processes delivering these impurities around Antarctica.

Published
2024

4. 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

Author

Cairns, Warren RL., Turetta, Clara, Maffezzoli, Niccolò, Magand, Olivier, Araujo, Beatriz Ferreira, Angot, Hélène, Segato, Delia, Cristofanelli, Paolo, Sprovieri, Francesca, Scarchilli, Claudio, Grigioni, Paolo, Ciardini, Virginia, Barbante, Carlo, Dommergue, Aurélien, and Spolaor, Andrea

Published
2021
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5. An annually resolved chronology for the Mount Brown South ice cores, East Antarctica

Author

Vance, Tessa R., Abram, Nerilie J., Criscitiello, Alison S., Crockart, Camilla K., Decampo, Aylin, Favier, Vincent, Gkinis, Vasileios, Harlan, Margaret, Jackson, Sarah L., Kjær, Helle A., Long, Chelsea A., Nation, Meredith K., Plummer, Christopher T., Segato, Delia, Spolaor, Andrea, Vallelonga, Paul T., Vance, Tessa R., Abram, Nerilie J., Criscitiello, Alison S., Crockart, Camilla K., Decampo, Aylin, Favier, Vincent, Gkinis, Vasileios, Harlan, Margaret, Jackson, Sarah L., Kjær, Helle A., Long, Chelsea A., Nation, Meredith K., Plummer, Christopher T., Segato, Delia, Spolaor, Andrea, and Vallelonga, Paul T.

Published
2024

6. Arctic mercury flux increased through the Last Glacial Termination with a warming climate

Author

A.P. Moller Foundation, University of Copenhagen, National Science Foundation (US), Alfred Wegener Institute Helmholtz Centre for Polar and Marine Research (Germany), National Institute of Polar Research (Japan), University of Bergen, Swiss National Science Foundation, Institut Polaire Français Paul Emile Victor, Institut des Géosciences de l'Environnement (France), University of Manitoba, Chinese Academy of Sciences, Beijing Normal University, European Commission, Ministry of Earth Sciences (India), Canada Research Chairs, Oeschger Centre for Climate Change Research (Switzerland), Aarhus University Research Foundation, Segato, Delia [0000-0003-3375-3319], Saiz-Lopez, A. [0000-0002-0060-1581], Mahajan, Anoop Sharad `[0000-0002-2909-5432], Wang, Feiyue [0000-0001-5297-0859], Corella, Juan Pablo [0000-0001-5127-9011], Cuevas, Carlos A. [0000-0002-9251-5460], Erhardt, Tobias [0000-0002-6683-6746], Zeppenfeld, Chantal [0000-0002-6340-5836], Kjær, Helle Astrid [0000-0002-3781-9509], Turetta, Clara [0000-0003-3130-2901], Cairns, Warren Raymond Lee [0000-0002-7128-7753], Barbante, Carlo [0000-0003-4177-2288], Spolaor, Andrea [0000-0001-8635-9193], Segato, Delia, Saiz-Lopez, A., Mahajan, Anoop Sharad, Wang, Feiyue, Corella, Juan Pablo, Cuevas, Carlos A., Erhardt, Tobias, Jensen, Camilla Marie, Zeppenfeld, Chantal, Kjær, Helle Astrid, Turetta, Clara, Cairns, Warren Raymond Lee, Barbante, Carlo, Spolaor, Andrea, A.P. Moller Foundation, University of Copenhagen, National Science Foundation (US), Alfred Wegener Institute Helmholtz Centre for Polar and Marine Research (Germany), National Institute of Polar Research (Japan), University of Bergen, Swiss National Science Foundation, Institut Polaire Français Paul Emile Victor, Institut des Géosciences de l'Environnement (France), University of Manitoba, Chinese Academy of Sciences, Beijing Normal University, European Commission, Ministry of Earth Sciences (India), Canada Research Chairs, Oeschger Centre for Climate Change Research (Switzerland), Aarhus University Research Foundation, Segato, Delia [0000-0003-3375-3319], Saiz-Lopez, A. [0000-0002-0060-1581], Mahajan, Anoop Sharad `[0000-0002-2909-5432], Wang, Feiyue [0000-0001-5297-0859], Corella, Juan Pablo [0000-0001-5127-9011], Cuevas, Carlos A. [0000-0002-9251-5460], Erhardt, Tobias [0000-0002-6683-6746], Zeppenfeld, Chantal [0000-0002-6340-5836], Kjær, Helle Astrid [0000-0002-3781-9509], Turetta, Clara [0000-0003-3130-2901], Cairns, Warren Raymond Lee [0000-0002-7128-7753], Barbante, Carlo [0000-0003-4177-2288], Spolaor, Andrea [0000-0001-8635-9193], Segato, Delia, Saiz-Lopez, A., Mahajan, Anoop Sharad, Wang, Feiyue, Corella, Juan Pablo, Cuevas, Carlos A., Erhardt, Tobias, Jensen, Camilla Marie, Zeppenfeld, Chantal, Kjær, Helle Astrid, Turetta, Clara, Cairns, Warren Raymond Lee, Barbante, Carlo, and Spolaor, Andrea

Abstract

Mercury is a pollutant of global concern, especially in the Arctic, where high levels are found in biota despite its remote location. Mercury is transported to the Arctic via atmospheric, oceanic and riverine long-range pathways, where it accumulates in aquatic and terrestrial ecosystems. While present-day mercury deposition in the Arctic from natural and anthropogenic emissions is extensively studied, the control of past climate changes on natural mercury variability remains unknown. Here we present an Arctic mercury record covering the Last Glacial Termination to the early Holocene epoch (15.7–9.0 thousand years before 2000 ce), collected as part of the East Greenland Ice-Core Project. We find a threefold increase in mercury depositional fluxes from the Last Glacial Termination into the early Holocene, which coincided with abrupt regional climate warming. Atmospheric chemistry modelling, combined with available sea-ice proxies, indicates that oceanic mercury evaporation and atmospheric bromine drove the increase in mercury flux during this climatic transition. Our results suggest that environmental changes associated with climate warming may contribute to increasing mercury levels in Arctic ecosystems.

Published
2023

7. 200-year ice core bromine reconstruction at Dome C (Antarctica): observational and modelling results

Author

European Commission, Programma Nazionale di Ricerche in Antartide, Royal Society (UK), Centre National de la Recherche Scientifique (France), Burgay, François [0000-0002-2657-6900], Fernández, Rafael Pedro [0000-0002-4114-5500], Segato, Delia [0000-0003-3375-3319], Turetta, Clara [0000-0003-3130-2901], Rhodes, Rachael H. [0000-0001-7511-1969], Scarchilli, Claudio [0000-0002-2414-2439], Barbante, Carlo [0000-0003-4177-2288], Saiz-Lopez, A. [0000-0002-0060-1581], Spolaor, Andrea [0000-0001-8635-9193], Burgay, François, Fernández, Rafael P., Segato, Delia, Turetta, Clara, Blaszczak-Boxe, Christopher S., Rhodes, Rachael H., Scarchilli, Claudio, Ciardini, Virginia, Barbante, Carlo, Saiz-Lopez, A., Spolaor, Andrea, European Commission, Programma Nazionale di Ricerche in Antartide, Royal Society (UK), Centre National de la Recherche Scientifique (France), Burgay, François [0000-0002-2657-6900], Fernández, Rafael Pedro [0000-0002-4114-5500], Segato, Delia [0000-0003-3375-3319], Turetta, Clara [0000-0003-3130-2901], Rhodes, Rachael H. [0000-0001-7511-1969], Scarchilli, Claudio [0000-0002-2414-2439], Barbante, Carlo [0000-0003-4177-2288], Saiz-Lopez, A. [0000-0002-0060-1581], Spolaor, Andrea [0000-0001-8635-9193], Burgay, François, Fernández, Rafael P., Segato, Delia, Turetta, Clara, Blaszczak-Boxe, Christopher S., Rhodes, Rachael H., Scarchilli, Claudio, Ciardini, Virginia, Barbante, Carlo, Saiz-Lopez, A., and Spolaor, Andrea

Abstract

Bromine enrichment (Brenr) has been proposed as an ice core proxy for past sea-ice reconstruction. Understanding the processes that influence bromine preservation in the ice is crucial to achieve a reliable interpretation of ice core signals and to potentially relate them to past sea-ice variability. Here, we present a 210 years bromine record that sheds light on the main processes controlling bromine preservation in the snow and ice at Dome C, East Antarctic plateau. Using observations alongside a modelling approach, we demonstrate that the bromine signal is preserved at Dome C and it is not affected by the strong variations in ultraviolet radiation reaching the Antarctic plateau due to the stratospheric ozone hole. Based on this, we investigate whether the Dome C Brenr record can be used as an effective tracer of past Antarctic sea ice. Due to the limited time window covered by satellite measurements and the low sea-ice variability observed during the last 30 years in East Antarctica, we cannot fully validate Brenr as an effective proxy for past sea-ice reconstructions at Dome C.

Published
2023

8. An annually resolved chronology for the Mount Brown South ice cores, East Antarctica.

Author

Vance, Tessa R., Abram, Nerilie J., Criscitiello, Alison S., Crockart, Camilla K., DeCampo, Aylin, Favier, Vincent, Gkinis, Vasileios, Harlan, Margaret, Jackson, Sarah L., Kjær, Helle A., Long, Chelsea A., Nation, Meredith K., Plummer, Christopher T., Segato, Delia, Spolaor, Andrea, and Vallelonga, Paul T.

Subjects
ICE cores, ATMOSPHERIC transport, CHEMICAL species, METEOROLOGY, SEASONS
Abstract

Climate reconstructions of the last millennium rely on networks of high-resolution and well-dated proxy records. This study presents age-at-depth data and preliminary results from the new Mount Brown South (MBS) ice cores, collected at an elevation of 2084 m on the boundary of Princess Elizabeth Land and Kaiser Wilhelm II Land in East Antarctica. We show an initial analysis of the site meteorology, mean annual chemical species concentrations and seasonal cycles, including the identification of a seasonal cycle in fluoride concentrations. The annually resolved chronologies were developed from the chemistry data using a site-specific layer-counting methodology that employed seasonally varying trace chemical species and stable water isotopic ratios, combined with alignment to known volcanic horizons. The uncertainty in the determination of annual horizons via layer counting was also quantified. The chronologies developed include the "Main" 295 m record spanning 1137 years (873–2009 CE) and three surface cores spanning the most recent 39–52 years up to the surface age at the time of drilling (austral summer 2017/2018). Mean annual trace chemical concentrations are compared to the Law Dome ice core (located 1130 km east of the Mount Brown South site) and discussed in terms of atmospheric transport. The MBS chronologies presented here – named MBS2023 – will underpin the development of new palaeoclimate records spanning the past millennium from this under-represented region of East Antarctica. [ABSTRACT FROM AUTHOR]

Published
2024
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9. An annually resolved chronology for the Mount Brown South ice cores, East Antarctica

Author

Vance, Tessa R., primary, Abram, Nerilie J., additional, Criscitiello, Alison S., additional, Crockart, Camilla K., additional, DeCampo, Aylin, additional, Favier, Vincent, additional, Gkinis, Vasileios, additional, Harlan, Margaret, additional, Jackson, Sarah L., additional, Kjær, Helle A., additional, Long, Chelsea A., additional, Nation, Meredith K., additional, Plummer, Chris T., additional, Segato, Delia, additional, Spolaor, Andrea, additional, and Vallelonga, Paul T., additional

Published
2023
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10. High-resolution aerosol data from the top 3.8 kyr of the East Greenland Ice coring Project (EGRIP) ice core

Author

Erhardt, Tobias, Jensen, Camilla Marie, Adolphi, Florian, Kjær, Helle Astrid, Dallmayr, Remi, Twarloh, Birthe, Behrens, Melanie, Hirabayashi, Motohiro, Fukuda, Kaori, Ogata, Jun, Burgay, François, Scoto, Federico, Crotti, Ilaria, Spagnesi, Azzurra, Maffezzoli, Niccoló, Segato, Delia, Paleari, Chiara, Mekhaldi, Florian, Muscheler, Raimund, Darfeuil, Sophie, Fischer, Hubertus, Erhardt, Tobias, Jensen, Camilla Marie, Adolphi, Florian, Kjær, Helle Astrid, Dallmayr, Remi, Twarloh, Birthe, Behrens, Melanie, Hirabayashi, Motohiro, Fukuda, Kaori, Ogata, Jun, Burgay, François, Scoto, Federico, Crotti, Ilaria, Spagnesi, Azzurra, Maffezzoli, Niccoló, Segato, Delia, Paleari, Chiara, Mekhaldi, Florian, Muscheler, Raimund, Darfeuil, Sophie, and Fischer, Hubertus

Published
2023

11. High resolution aerosol data from the top 3.8 ka of the EGRIP ice core

Author

Erhardt, Tobias, Jensen, Camilla Marie, Adolphi, Florian, Kjær, Helle Astrid, Dallmayr, Remi, Twarloh, Birthe, Behrens, Melanie, Hirabayashi, Motohiro, Fukuda, Kaori, Ogata, Jun, Burgay, François, Scoto, Federico, Crotti, Ilaria, Spagnesi, Azzurra, Maffezzoli, Niccoló, Segato, Delia, Paleari, Chiara, Mekhaldi, Florian, Muscheler, Raimund, Darfeuil, Sophie, and Fischer, Hubertus

Abstract

Here we present the high-resolution CFA data from the top 479 m of the East Greenland Ice coring Project (EGRIP) ice core covering the past 3.8 thousand years. The data consists of 1 mm-depth-resolution profiles of calcium, sodium, am- monium, nitrate and electrolytic conductivity as well as decadal averages of these profiles. Alongside the data we provide a description of the measurement setup, procedures, the relevant references for the specific methods as well as an assessment of the precision of the measurements, the sample to depth assignment and the depth and temporal resolution of the data set. The nominally 1-mm data represents an oversampling of the record as the true resolution is limited by the analytical setup to approximately 1 cm. The error of absolute depth assignment of the data may be on the order of 1 cm, however relative depth offsets be- tween the records of the individual species is only on the order of 1 mm. The presented data has sub-annual resolution over the entire depth range and has already formed part of the data for an annually layer-counted time scale for the EGRIP ice core used to improve and revise the multi-core Greenland ice-core chronology (GICC05) to a new version,GICC21 (Sinnl et al., 2021). The data is available in full 1-mm resolution and decadal averages on PANGAEA (https://doi.org/10.1594/PANGAEA.945293 (Erhardt et al., 2022b))

Published
2023

12. 200-year ice core bromine reconstruction at Dome C (Antarctica): observational and modelling results

Author

Burgay, François, primary, Fernández, Rafael Pedro, additional, Segato, Delia, additional, Turetta, Clara, additional, Blaszczak-Boxe, Christopher S., additional, Rhodes, Rachael H., additional, Scarchilli, Claudio, additional, Ciardini, Virginia, additional, Barbante, Carlo, additional, Saiz-Lopez, Alfonso, additional, and Spolaor, Andrea, additional

Published
2023
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13. An annually resolved chronology for the Mount Brown South ice cores, East Antarctica.

Author

Vance, Tessa R., Abram, Nerilie J., Criscitiello, Alison S., Crockart, Camilla K., DeCampo, Aylin, Favier, Vincent, Gkinis, Vasileios, Harlan, Margaret, Jackson, Sarah L., Kjær, Helle A., Long, Chelsea A., Nation, Meredith, Plummer, Chris T., Segato, Delia, Spolaor, Andrea, and Vallelonga, Paul T.

Abstract

Climate reconstructions of the last millennium rely on networks of high resolution and well-dated proxy records. This study presents age-at-depth data and preliminary results from the new Mount Brown South ice cores, collected at an elevation of 2,084 metres on the boundary of Princess Elizabeth and Kaiser Wilhelm II Land in East Antarctica. We show an initial analysis of the site meteorology, mean annual chemical species concentrations, and seasonal cycles including analysis of a seasonal cycle in fluoride concentrations with a potential link to sea ice formation. The annually resolved chronologies were developed from this data using a site-specific layer-counting methodology which employed seasonally varying trace chemical species and water isotope ratios, combined with a volcanic horizon alignment approach. The chronologies developed include the 'Main' 295 m record spanning 1,137 years (873-2009 CE), and three surface cores spanning the most recent 39-52 years up to the surface age at the time of drilling (austral summer 2017/2018). Mean annual trace chemical concentrations are compared to the Law Dome ice core further to the east and discussed in terms of atmospheric transport, and the uncertainty in the determination of annual horizons via layer counting is quantified. The MBS chronologies presented here - named MBS2023 - will underpin the development of new palaeoclimate records spanning the past millennium from this under-represented region of East Antarctica. [ABSTRACT FROM AUTHOR]

Published
2023
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14. Supplementary material to "200-years ice core bromine reconstruction at Dome C (Antarctica): observational and modelling results"

Author

Burgay, François, primary, Fernández, Rafael Pedro, additional, Segato, Delia, additional, Turetta, Clara, additional, Blaszczak-Boxe, Christopher S., additional, Rhodes, Rachael H., additional, Scarchilli, Claudio, additional, Ciardini, Virginia, additional, Barbante, Carlo, additional, Saiz-Lopez, Alfonso, additional, and Spolaor, Andrea, additional

Published
2022
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15. 200-years ice core bromine reconstruction at Dome C (Antarctica): observational and modelling results

Author

Burgay, François, primary, Fernández, Rafael Pedro, additional, Segato, Delia, additional, Turetta, Clara, additional, Blaszczak-Boxe, Christopher S., additional, Rhodes, Rachael H., additional, Scarchilli, Claudio, additional, Ciardini, Virginia, additional, Barbante, Carlo, additional, Saiz-Lopez, Alfonso, additional, and Spolaor, Andrea, additional

Published
2022
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18. Five thousand years of fire history in the high North Atlantic region: natural variability and ancient human forcing

Author

Segato, Delia, primary, Villoslada Hidalgo, Maria Del Carmen, additional, Edwards, Ross, additional, Barbaro, Elena, additional, Vallelonga, Paul, additional, Kjær, Helle Astrid, additional, Simonsen, Marius, additional, Vinther, Bo, additional, Maffezzoli, Niccolò, additional, Zangrando, Roberta, additional, Turetta, Clara, additional, Battistel, Dario, additional, Vésteinsson, Orri, additional, Barbante, Carlo, additional, and Spolaor, Andrea, additional

Published
2021
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19. An age scale for the first shallow (sub-)Antarctic ice core from Young Island, Northwest Ross Sea

Author

Moser, Dorothea Elisabeth, Jackson, Sarah, Kjær, Helle Astrid, Markle, Bradley, Ngoumtsa, Estelle, Pedro, Joel B., Segato, Delia, Spolaor, andrea, Tetzner, Dieter, Vallelonga, Paul, Thomas, Elizabeth R., Moser, Dorothea Elisabeth, Jackson, Sarah, Kjær, Helle Astrid, Markle, Bradley, Ngoumtsa, Estelle, Pedro, Joel B., Segato, Delia, Spolaor, andrea, Tetzner, Dieter, Vallelonga, Paul, and Thomas, Elizabeth R.

Abstract

The climate of the sub-Antarctic is important in understanding the environmental conditions of Antarctica and the Southern Ocean. However, regional climate proxy records from this region are scarce. In this study, we present the stable water isotopes, major ion chemistry, and dust records from the first ice core from the (sub-)Antarctic Young Island. We present and discuss various dating approaches based on commonly used ice core proxies, such as stable water isotopes and seasonally deposited ions, together with site-specific characteristics such as melt layers. The dating approaches are compared with estimated precipitation rates from reanalysis data (ERA5) and volcanic cryptotephra shards likely presenting an absolute tie point from a 2001 CE eruption on neighboring Sturge Island. The resulting ice core age scale spans the period 2016 to 1995, with an uncertainty of ±2 years.

Published
2021

20. Five thousand years of fire history in the high North Atlantic region:natural variability and ancient human forcing

Author

Segato, Delia, Villoslada Hidalgo, Maria Del Carmen, Edwards, Ross, Barbaro, Elena, Vallelonga, Paul, Kjaer, Helle Astrid, Simonsen, Marius, Vinther, Bo, Maffezzoli, Niccolo, Zangrando, Roberta, Turetta, Clara, Battistel, Dario, Vesteinsson, Orri, Barbante, Carlo, Spolaor, Andrea, Segato, Delia, Villoslada Hidalgo, Maria Del Carmen, Edwards, Ross, Barbaro, Elena, Vallelonga, Paul, Kjaer, Helle Astrid, Simonsen, Marius, Vinther, Bo, Maffezzoli, Niccolo, Zangrando, Roberta, Turetta, Clara, Battistel, Dario, Vesteinsson, Orri, Barbante, Carlo, and Spolaor, Andrea

Abstract

Biomass burning influences global atmospheric chemistry by releasing greenhouse gases and climate-forcing aerosols. There is controversy about the magnitude and timing of Holocene changes in biomass burning emissions from millennial to centennial timescales and, in particular, about the possible impact of ancient civilizations. Here we present a 5 kyr record of fire activity proxies levoglucosan, black carbon, and ammonium measured in the RECAP (Renland ice cap) ice core, drilled in coastal eastern Greenland, and therefore affected by processes occurring in the high North Atlantic region. Levoglucosan and ammonium fluxes are high from 5 to 4.5 kyr BP (thousand years before 2000 CE) followed by an abrupt decline, possibly due to monotonic decline in Northern Hemisphere summer insolation. Levoglucosan and black carbon show an abrupt decline at 1.1 kyr BP, suggesting a decline in the wildfire regime in Iceland due to the extensive land clearing caused by Viking colonizers. All fire proxies reach a minimum during the second half of the last century, after which levoglucosan and ammonium fluxes increase again, in particular over the last 200 years. We find that the fire regime reconstructed from RECAP fluxes seems mainly related to climatic changes; however over the last mil-lennium human activities might have influenced wildfire frequency/occurrence substantially.

Published
2021

21. 200-years ice core bromine reconstruction at Dome C (Antarctica): observational and modelling results.

Author

Burgay, François, Fernandez, Rafael P., Segato, Delia, Turetta, Clara, Blaszczak-Boxe, Christopher S., Rhodes, Rachael. H., Scarchilli, Claudio, Ciardini, Virginia, Barbante, Carlo, Saiz-Lopez, Alfonso, and Spolaor, Andrea

Abstract

Bromine enrichment (Brenr) has been proposed as an ice core proxy for past sea-ice reconstruction. Understanding the processes that influence bromine preservation in the ice is crucial to achieve a reliable interpretation of ice core signals and to potentially relate them to past sea-ice variability. Here, we present a 210-years bromine record that sheds light on the main processes controlling bromine preservation in the snow and ice at Dome C, East Antarctic plateau. Using observations alongside a modelling approach, we demonstrate that the bromine signal is preserved at Dome C, and it is not affected by the strong variations in ultraviolet radiation reaching the Antarctic plateau due to the stratospheric ozone hole. Based on this, we investigate whether the Dome C Brenr record can be used as an effective tracer of past Antarctic sea-ice. Due to the limited time window covered by satellite measurements and the low sea-ice variability observed during the last 30 years in East Antarctica, at this stage we cannot fully validate Brenr as an effective proxy for past sea-ice reconstructions at Dome C. [ABSTRACT FROM AUTHOR]

Published
2022
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22. 5 kyr of fire history in the High North Atlantic Region: natural variability and ancient human forcing

Author

Segato, Delia, primary, Villoslada Hidalgo, Maria Del Carmen, additional, Edwards, Ross, additional, Barbaro, Elena, additional, Vallelonga, Paul, additional, Kjær, Helle Astrid, additional, Simonsen, Marius, additional, Vinther, Bo, additional, Maffezzoli, Niccolò, additional, Zangrando, Roberta, additional, Turetta, Clara, additional, Battistel, Dario, additional, Vésteinsson, Orri, additional, Barbante, Carlo, additional, and Spolaor, Andrea, additional

Published
2021
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23. Supplementary material to "5 kyr of fire history in the High North Atlantic Region: natural variability and ancient human forcing"

Author

Segato, Delia, primary, Villoslada Hidalgo, Maria Del Carmen, additional, Edwards, Ross, additional, Barbaro, Elena, additional, Vallelonga, Paul, additional, Kjær, Helle Astrid, additional, Simonsen, Marius, additional, Vinther, Bo, additional, Maffezzoli, Niccolò, additional, Zangrando, Roberta, additional, Turetta, Clara, additional, Battistel, Dario, additional, Vésteinsson, Orri, additional, Barbante, Carlo, additional, and Spolaor, Andrea, additional

Published
2021
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24. A shift to predominant multi-year sea ice conditions in the Baffin Bay and North Atlantic Ocean during the Holocene-Glacial transition inferred from the EGRIP ice core

Author

Segato, Delia, primary, Burgay, Francois, additional, Maffezzoli, Niccolò, additional, Spagnesi, Azzurra, additional, Turetta, Clara, additional, Scoto, Federico, additional, Dallo, Federico, additional, Zannoni, Daniele, additional, Erhardt, Tobias, additional, Jensen, Camilla Marie, additional, Saiz-Lopez, Alfonso, additional, Kjær, Helle Astrid, additional, Dahl-Jensen, Dorthe, additional, Barbante, Carlo, additional, and Spolaor, Andrea, additional

Published
2021
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25. 5 kyr of fire history in the High North Atlantic Region: natural variability and ancient human forcing.

Author

Segato, Delia, Hidalgo, Maria Del Carmen Villoslada, Edwards, Ross, Barbaro, Elena, Vallelonga, Paul, Kjær, Helle Astrid, Simonsen, Marius, Vinther, Bo, Maffezzoli, Niccolò, Zangrando, Roberta, Turetta, Clara, Battistel, Dario, Vésteinsson, Orri, Barbante, Carlo, and Spolaor, Andrea

Abstract

Biomass burning influences global atmospheric chemistry by releasing greenhouse gases and climate-forcing aerosols. There is controversy about the magnitude and timing of Holocene changes in biomass burning emissions from millennial to centennial time scales and, in particular, on the possible impact of ancient civilizations. Here we present a 5 kyr record of fire activity proxies levoglucosan, black carbon and ammonium measured in the RECAP ice core, drilled in the coastal East Greenland and therefore affected by processes occurring in the High North Atlantic Region. Levoglucosan and ammonium fluxes show high levels from 5 to 4.5 kyr followed by an abrupt decline, possibly due to monotonic decline in Northern Hemisphere summer insolation. Levoglucosan and black carbon show an abrupt decline at 1.1 kyr BP (before 2000 AD), suggesting a decline in wildfire regime in the Icelandic territory due to the extensive land clearing caused by Viking colonizers. A minimum is reached at 0.5 kyr BP for all fire proxies, after which levoglucosan and ammonium fluxes increase again, in particular over the last 200 years. We find that the fire regime reconstructed from RECAP fluxes seems mainly related to climatic changes, however over the last millennium human activities might have had a substantial influence controlling the occurrence of fire. [ABSTRACT FROM AUTHOR]

Published
2021
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26. Arctic mercury flux increased through the Last Glacial Termination with a warming climate

Author

Delia Segato, Alfonso Saiz-Lopez, Anoop Sharad Mahajan, Feiyue Wang, Juan Pablo Corella, Carlos Alberto Cuevas, Tobias Erhardt, Camilla Marie Jensen, Chantal Zeppenfeld, Helle Astrid Kjær, Clara Turetta, Warren Raymond Lee Cairns, Carlo Barbante, Andrea Spolaor, A.P. Moller Foundation, University of Copenhagen, National Science Foundation (US), Alfred Wegener Institute Helmholtz Centre for Polar and Marine Research (Germany), National Institute of Polar Research (Japan), University of Bergen, Swiss National Science Foundation, Institut Polaire Français Paul Emile Victor, Institut des Géosciencies de l'Environnement, University of Manitoba, Chinese Academy of Sciences, Beijing Normal University, European Commission, Ministry of Earth Sciences (India), Canada Research Chairs, Oeschger Centre for Climate Change Research, Aarhus University Research Foundation, Segato, Delia, Saiz-Lopez, A., Mahajan, Anoop Sharad `, Wang, Feiyue, Corella, Juan Pablo, Cuevas, Carlos A., Erhardt, Tobias, Zeppenfeld, Chantal, Kjær, Helle Astrid, Turetta, Clara, Cairns, Warren Raymond Lee, Barbante, Carlo, and Spolaor, Andrea

Subjects
General Earth and Planetary Sciences
Abstract

9 pags., 3 figs., Mercury is a pollutant of global concern, especially in the Arctic, where high levels are found in biota despite its remote location. Mercury is transported to the Arctic via atmospheric, oceanic and riverine long-range pathways, where it accumulates in aquatic and terrestrial ecosystems. While present-day mercury deposition in the Arctic from natural and anthropogenic emissions is extensively studied, the control of past climate changes on natural mercury variability remains unknown. Here we present an Arctic mercury record covering the Last Glacial Termination to the early Holocene epoch (15.7–9.0 thousand years before 2000 ce), collected as part of the East Greenland Ice-Core Project. We find a threefold increase in mercury depositional fluxes from the Last Glacial Termination into the early Holocene, which coincided with abrupt regional climate warming. Atmospheric chemistry modelling, combined with available sea-ice proxies, indicates that oceanic mercury evaporation and atmospheric bromine drove the increase in mercury flux during this climatic transition. Our results suggest that environmental changes associated with climate warming may contribute to increasing mercury levels in Arctic ecosystems., It is supported by funding agencies and institutions in Denmark (A. P. Møller Foundation, University of Copenhagen), USA (US National Science Foundation, Office of Polar Programs), Germany (Alfred Wegener Institute, Helmholtz Centre for Polar and Marine Research), Japan (National Institute of Polar Research and Arctic Challenge for Sustainability), Norway (University of Bergen and Trond Mohn Foundation), Switzerland (Swiss National Science Foundation), France (French Polar Institute Paul-Emile Victor, Institute for Geosciences and Environmental research), Canada (University of Manitoba) and China (Chinese Academy of Sciences and Beijing Normal University). A.S. acknowledges the ‘Programma di Ricerca in Artico’ (PRA, project number PRA2019-0011, Sentinel) for supporting this work. A.S.-L. received funding from the European Research Council Executive Agency under the European Union’s Horizon 2020 Research and Innovation Programme (project ERC-2016-COG 726349 CLIMAHAL). This work represents a contribution to CSIC Thematic Interdisciplinary Platform PTI POLARCSIC. A.S.M. acknowledges the Indian Institute of Tropical Meteorology (IITM), funded by the Ministry of Earth Sciences (MOES), Government of India (GOI). F.W. received funding from the Canada Research Chairs Program. T.E., C.M.J. and C.Z. acknowledge the long-term support of ice-core research by the Swiss National Science Foundation (SNSF) under the project numbers 200020_172506, 200020B_200328 and 20FI21_164190 as well as the Oeschger Center for Climate Change Research. H.A.K. received funding from the DFF Inge Lehmann grant 1131-00007B ‘Holocene sea ice variability in the Arctic’. ELGA LabWater, High Wycombe, UK, supplied the pure-water system used in this study.

Published
2023

27. 200-year ice core bromine reconstruction at Dome C (Antarctica): observational and modelling results

Author

François Burgay, Rafael Pedro Fernández, Delia Segato, Clara Turetta, Christopher S. Blaszczak-Boxe, Rachael H. Rhodes, Claudio Scarchilli, Virginia Ciardini, Carlo Barbante, Alfonso Saiz-Lopez, Andrea Spolaor, European Commission, Programma Nazionale di Ricerche in Antartide, Royal Society (UK), Centre National de la Recherche Scientifique (France), Burgay, François, Fernández, Rafael Pedro, Segato, Delia, Turetta, Clara, Rhodes, Rachael H., Scarchilli, Claudio, Barbante, Carlo, Saiz-Lopez, A., and Spolaor, Andrea

Subjects
Earth-Surface Processes, Water Science and Technology
Abstract

15 pags., 4 figs., 2 tabs., Bromine enrichment (Brenr) has been proposed as an ice core proxy for past sea-ice reconstruction. Understanding the processes that influence bromine preservation in the ice is crucial to achieve a reliable interpretation of ice core signals and to potentially relate them to past sea-ice variability. Here, we present a 210 years bromine record that sheds light on the main processes controlling bromine preservation in the snow and ice at Dome C, East Antarctic plateau. Using observations alongside a modelling approach, we demonstrate that the bromine signal is preserved at Dome C and it is not affected by the strong variations in ultraviolet radiation reaching the Antarctic plateau due to the stratospheric ozone hole. Based on this, we investigate whether the Dome C Brenr record can be used as an effective tracer of past Antarctic sea ice. Due to the limited time window covered by satellite measurements and the low sea-ice variability observed during the last 30 years in East Antarctica, we cannot fully validate Brenr as an effective proxy for past sea-ice reconstructions at Dome C., This research has been supported by the Horizon 2020 (Beyond EPICA; grant no. 815384), by the Programma Nazionale per la Ricerca in Antartide (PNRA; project no. PNRA16_00295), and by the bilateral international exchange award Royal Society (UK)-CNR, titled “Antarctic sea-ice history: developing robust ice core proxies” (grant no. IEC/R2/202110), awarded to Rachael H. Rhodes and Andrea Spolaor.

Published
2023

28. An age scale for the first shallow (Sub-)antarctic ice core from young island, northwest ross sea

Author

Helle Astrid Kjær, Dieter Tetzner, B. R. Markle, Joel B Pedro, Delia Segato, Dorothea Elisabeth Moser, Sarah Jackson, Andrea Spolaor, Elizabeth R. Thomas, Paul Vallelonga, Estelle Ngoumtsa, Moser, Dorothea Elisabeth [0000-0001-9085-9713], Segato, Delia [0000-0003-3375-3319], Thomas, Elizabeth R. [0000-0002-3010-6493], and Apollo - University of Cambridge Repository

Subjects
QE1-996.5, geography, geography.geographical_feature_category, melting, shallow ice core, Geology, (sub-)Antarctic island, proxies, Sub antarctic, age scale, Volcano, Ice core, Settore GEO/08 - Geochimica e Vulcanologia, Period (geology), General Earth and Planetary Sciences, Physical geography, Precipitation, Scale (map)
Abstract

The climate of the sub-Antarctic is important in understanding the environmental conditions of Antarctica and the Southern Ocean. However, regional climate proxy records from this region are scarce. In this study, we present the stable water isotopes, major ion chemistry, and dust records from the first ice core from the (sub-)Antarctic Young Island. We present and discuss various dating approaches based on commonly used ice core proxies, such as stable water isotopes and seasonally deposited ions, together with site-specific characteristics such as melt layers. The dating approaches are compared with estimated precipitation rates from reanalysis data (ERA5) and volcanic cryptotephra shards likely presenting an absolute tie point from a 2001 CE eruption on neighboring Sturge Island. The resulting ice core age scale spans the period 2016 to 1995, with an uncertainty of ±2 years.

Published
2021
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29. PRA Melting-ICE Project: Svalbard 2022 Expeditions Report.

Author

Montemagno F, Cascone M, Cardellini C, Pasotti J, Manini E, Baldrighi E, Maiero E, Segato D, Cerrato R, Mazzola M, Vardè M, Cordone A, Caliro S, Rudnik I, Cramm M, Bradley J, and Giovannelli D

Abstract

Arctic regions are among the fastest warming areas of the planet. Increasing average temperatures over the last five decades have deepened the thawing of the upper-most layer of permafrost across the Arctic, which contains significant amounts of organic carbon. The progressive deepening of seasonal thawing releases carbon that is used by active microorganisms which also produce greenhouse gases, potentially onsetting a positive feedback on global warming. Despite their importance in controlling organic matter degradation and greenhouse gas fluxes to the atmosphere, there is a lack of data on activity and dynamics of microbial communities in High Arctic soils in response to seasonal thaw. This report describes three specific expeditions performed on the Svalbard archipelago, carried out within the framework of the PRA (Italian Arctic Research Program) project Melting-ICE, performed between February and October 2022, reporting site characteristics and samples collected. The project aims to investigate the diversity and activity of active layer microbial communities across a full season thaw cycle, correlating microbial diversity with gas fluxes and composition. During these expeditions, a total of eight different sites were selected to investigate the microbiology and geochemistry of soils, as well as to estimate the gas fluxes from the soil to the atmosphere. The data collected in the field, combined with the results obtained in the laboratory, will provide a snapshot of the seasonal activity of the microbial communities present in the permafrost's active layer. The three campaigns will provide data to estimate the impact of permafrost melting on the carbon cycle and the role of microorganisms in the release of greenhouse gases., Competing Interests: No competing interests were disclosed., (Copyright: © 2024 Montemagno F et al.)

Published
2024
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