117 results on '"Evangeliou, N."'
Search Results
2. An aerosol particle containing enriched uranium encountered in the remote upper troposphere
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Murphy, D.M., Froyd, K.D., Apel, E., Blake, D., Blake, N., Evangeliou, N., Hornbrook, R.S., Peischl, J., Ray, E., Ryerson, T.B., Thompson, C., and Stohl, A.
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- 2018
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3. Atmospheric transport is a major pathway of microplastics to remote regions
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Evangeliou, N., Grythe, H., Klimont, Z., Heyes, C., Eckhardt, S., Lopez-Aparicio, S., and Stohl, A.
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- 2020
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4. Fire evolution in the radioactive forests of Ukraine and Belarus: future risks for the population and the environment
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Evangeliou, N., Balkanski, Y., Cozic, A., Hao, W. M., Mouillot, F., Thonicke, K., Paugam, R., Zibtsev, S., Mousseau, T. A., Wang, R., Poulter, B., Petkov, A., Yue, C., Cadule, P., Koffi, B., Kaiser, J. W., and Møller, A. P.
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- 2015
5. Mortality induced by PM2.5 exposure following the 1783 Laki eruption using reconstructed meteorological fields
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Balkanski, Y., Menut, L., Garnier, E., Wang, R., Evangeliou, N., Jourdain, S., Eschstruth, C., Vrac, M., and Yiou, P.
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- 2018
- Full Text
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6. Drone-vs-Bird Detection Challenge at ICIAP 2021
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Coluccia, A, Fascista, A, Schumann, A, Sommer, L, Dimou, A, Zarpalas, D, Sharma, N, Nalamati, M, Eryuksel, O, Ozfuttu, KA, Akyon, FC, Sahin, K, Buyukborekci, E, Cavusoglu, D, Altinuc, S, Xing, D, Unlu, HU, Evangeliou, N, Tzes, A, Nayak, A, Bouazizi, M, Ahmad, T, Gonçalves, A, Rigault, B, Jain, R, Matsuo, Y, Prendinger, H, Jajaga, E, Rushiti, V, Ramadani, B, Pavleski, D, Coluccia, A, Fascista, A, Schumann, A, Sommer, L, Dimou, A, Zarpalas, D, Sharma, N, Nalamati, M, Eryuksel, O, Ozfuttu, KA, Akyon, FC, Sahin, K, Buyukborekci, E, Cavusoglu, D, Altinuc, S, Xing, D, Unlu, HU, Evangeliou, N, Tzes, A, Nayak, A, Bouazizi, M, Ahmad, T, Gonçalves, A, Rigault, B, Jain, R, Matsuo, Y, Prendinger, H, Jajaga, E, Rushiti, V, Ramadani, B, and Pavleski, D
- Abstract
This paper reports the results of the 5th edition of the “Drone-vs-Bird” detection challenge, organized within the 21st International Conference on Image Analysis and Processing (ICIAP). By taking as input video samples recorded by common cameras, the aim of the challenge is to devise advanced approaches aimed at spotlighting the presence of drones flying in the monitored area, while limiting the number of wrong alarms raised when similar flying entities such as birds suddenly appear in the scene. To this end, a number of important issues such as the dynamic variations in the scene and the background/foreground motion effects should be carefully considered, so as to allow the proposed solutions to correctly identify drones only when they are actually present. The paper summarizes the novel algorithms proposed by the four participating teams that succeeded in providing satisfactory detection performance on the 2022 challenge dataset.
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- 2022
7. Clean air policies are key for successfully mitigating Arctic warming
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von Salzen, K., Whaley, C.H., Anenberg, S.C., Van Dingenen, R., Klimont, Z., Flanner, M.G., Mahmood, R., Arnold, S.R., Beagley, S., Chien, R.-Y., Christensen, J.H., Eckhardt, S., Ekman, A.M.L., Evangeliou, N., Faluvegi, G., Fu, J.S., Gauss, M., Gong, W., Hjorth, J.L., Im, U., Krishnan, S., Kupiainen, K., Kühn, T., Langner, J., Law, K.S., Marelle, L., Olivié, D., Onishi, T., Oshima, N., Paunu, V.-V., Peng, Y., Plummer, D., Pozzoli, L., Rao, S., Raut, J.-C., Sand, M., Schmale, J., Sigmond, M., Thomas, M.A., Tsigaridis, K., Tsyro, S., Turnock, S.T., Wang, M., Winter, B., von Salzen, K., Whaley, C.H., Anenberg, S.C., Van Dingenen, R., Klimont, Z., Flanner, M.G., Mahmood, R., Arnold, S.R., Beagley, S., Chien, R.-Y., Christensen, J.H., Eckhardt, S., Ekman, A.M.L., Evangeliou, N., Faluvegi, G., Fu, J.S., Gauss, M., Gong, W., Hjorth, J.L., Im, U., Krishnan, S., Kupiainen, K., Kühn, T., Langner, J., Law, K.S., Marelle, L., Olivié, D., Onishi, T., Oshima, N., Paunu, V.-V., Peng, Y., Plummer, D., Pozzoli, L., Rao, S., Raut, J.-C., Sand, M., Schmale, J., Sigmond, M., Thomas, M.A., Tsigaridis, K., Tsyro, S., Turnock, S.T., Wang, M., and Winter, B.
- Abstract
A tighter integration of modeling frameworks for climate and air quality is urgently needed to assess the impacts of clean air policies on future Arctic and global climate. We combined a new model emulator and comprehensive emissions scenarios for air pollutants and greenhouse gases to assess climate and human health co-benefits of emissions reductions. Fossil fuel use is projected to rapidly decline in an increasingly sustainable world, resulting in far-reaching air quality benefits. Despite human health benefits, reductions in sulfur emissions in a more sustainable world could enhance Arctic warming by 0.8 °C in 2050 relative to the 1995–2014, thereby offsetting climate benefits of greenhouse gas reductions. Targeted and technically feasible emissions reduction opportunities exist for achieving simultaneous climate and human health co-benefits. It would be particularly beneficial to unlock a newly identified mitigation potential for carbon particulate matter, yielding Arctic climate benefits equivalent to those from carbon dioxide reductions by 2050.
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- 2022
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8. Radioactive pollution in Athens, Greece due to the Fukushima nuclear accident
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Kritidis, P., Florou, H., Eleftheriadis, K., Evangeliou, N., Gini, M., Sotiropoulou, M., Diapouli, E., and Vratolis, S.
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- 2012
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9. Temporal and spatial distribution of 137Cs in Eastern Mediterranean Sea. Horizontal and vertical dispersion in two regions
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Evangeliou, N., Florou, H., Bokoros, P., and Scoullos, M.
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- 2009
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10. Reviews and syntheses: Arctic fire regimes and emissions in the 21st century
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McCarty, J.L., Aalto, J., Paunu, V.-V., Arnold, S.R., Eckhardt, S., Klimont, Z., Fain, J.J., Evangeliou, N., Venäläinen, A., Tchebakova, N.M., Parfenova, E.I., Kupiainen, K., Soja, A.J., Huang, L., Wilson, S., McCarty, J.L., Aalto, J., Paunu, V.-V., Arnold, S.R., Eckhardt, S., Klimont, Z., Fain, J.J., Evangeliou, N., Venäläinen, A., Tchebakova, N.M., Parfenova, E.I., Kupiainen, K., Soja, A.J., Huang, L., and Wilson, S.
- Abstract
In recent years, the pan-Arctic region has experienced increasingly extreme fire seasons. Fires in the northern high latitudes are driven by current and future climate change, lightning, fuel conditions, and human activity. In this context, conceptualizing and parameterizing current and future Arctic fire regimes will be important for fire and land management as well as understanding current and predicting future fire emissions. The objectives of this review were driven by policy questions identified by the Arctic Monitoring and Assessment Programme (AMAP) Working Group and posed to its Expert Group on Short-Lived Climate Forcers. This review synthesizes current understanding of the changing Arctic and boreal fire regimes, particularly as fire activity and its response to future climate change in the pan-Arctic have consequences for Arctic Council states aiming to mitigate and adapt to climate change in the north. The conclusions from our synthesis are the following. (1) Current and future Arctic fires, and the adjacent boreal region, are driven by natural (i.e. lightning) and human-caused ignition sources, including fires caused by timber and energy extraction, prescribed burning for landscape management, and tourism activities. Little is published in the scientific literature about cultural burning by Indigenous populations across the pan-Arctic, and questions remain on the source of ignitions above 70∘ N in Arctic Russia. (2) Climate change is expected to make Arctic fires more likely by increasing the likelihood of extreme fire weather, increased lightning activity, and drier vegetative and ground fuel conditions. (3) To some extent, shifting agricultural land use and forest transitions from forest–steppe to steppe, tundra to taiga, and coniferous to deciduous in a warmer climate may increase and decrease open biomass burning, depending on land use in addition to climate-driven biome shifts. However, at the country and landscape scales, these relationships are n
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- 2021
11. Aerosol carbonaceous, elemental and ionic composition variability and origin at the Siberian High Arctic, Cape Baranova
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Manousakas, M., primary, Popovicheva, O., additional, Evangeliou, N., additional, Diapouli, E., additional, Sitnikov, N., additional, Shonija, N., additional, and Eleftheriadis, K., additional
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- 2020
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12. Source apportionment of circum-Arctic atmospheric black carbon from isotopes and modeling
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Winiger, Patrik, Barrett, T. E., Sheesley, R. J., Huang, L., Sharma, S., Barrie, Leonard A., Yttri, K. E., Evangeliou, N., Eckhardt, S., Stohl, A., Klimont, Z., Heyes, C., Semiletov, I. P., Dudarev, O., Charkin, A., Shakhova, N., Holmstrand, Henry, Andersson, August, Gustafsson, Örjan, Winiger, Patrik, Barrett, T. E., Sheesley, R. J., Huang, L., Sharma, S., Barrie, Leonard A., Yttri, K. E., Evangeliou, N., Eckhardt, S., Stohl, A., Klimont, Z., Heyes, C., Semiletov, I. P., Dudarev, O., Charkin, A., Shakhova, N., Holmstrand, Henry, Andersson, August, and Gustafsson, Örjan
- Abstract
Black carbon (BC) contributes to Arctic climate warming, yet source attributions are inaccurate due to lacking observational constraints and uncertainties in emission inventories. Year-round, isotope-constrained observations reveal strong seasonal variations in BC sources with a consistent and synchronous pattern at all Arctic sites. These sources were dominated by emissions from fossil fuel combustion in the winter and by biomass burning in the summer. The annual mean source of BC to the circum-Arctic was 39 +/- 10% from biomass burning. Comparison of transport-model predictions with the observations showed good agreement for BC concentrations, with larger discrepancies for (fossil/biomass burning) sources. The accuracy of simulated BC concentration, but not of origin, points to misallocations of emissions in the emission inventories. The consistency in seasonal source contributions of BC throughout the Arctic provides strong justification for targeted emission reductions to limit the impact of BC on climate warming in the Arctic and beyond.
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- 2019
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13. Perfluorocyclobutane (PFC-318, c-C4F8) in the global atmosphere
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Mühle, J, Mühle, J, Trudinger, CM, Western, LM, Rigby, M, Vollmer, MK, Park, S, Manning, AJ, Say, D, Ganesan, A, Paul Steele, L, Ivy, DJ, Arnold, T, Li, S, Stohl, A, Harth, CM, Salameh, PK, McCulloch, A, O'Doherty, S, Park, MK, Ok Jo, C, Young, D, Stanley, KM, Krummel, PB, Mitrevski, B, Hermansen, O, Lunder, C, Evangeliou, N, Yao, B, Kim, J, Hmiel, B, Buizert, C, Petrenko, VV, Arduini, J, Maione, M, Etheridge, DM, Michalopoulou, E, Czerniak, M, Severinghaus, JP, Reimann, S, Simmonds, PG, Fraser, PJ, Prinn, RG, Weiss, RF, Mühle, J, Mühle, J, Trudinger, CM, Western, LM, Rigby, M, Vollmer, MK, Park, S, Manning, AJ, Say, D, Ganesan, A, Paul Steele, L, Ivy, DJ, Arnold, T, Li, S, Stohl, A, Harth, CM, Salameh, PK, McCulloch, A, O'Doherty, S, Park, MK, Ok Jo, C, Young, D, Stanley, KM, Krummel, PB, Mitrevski, B, Hermansen, O, Lunder, C, Evangeliou, N, Yao, B, Kim, J, Hmiel, B, Buizert, C, Petrenko, VV, Arduini, J, Maione, M, Etheridge, DM, Michalopoulou, E, Czerniak, M, Severinghaus, JP, Reimann, S, Simmonds, PG, Fraser, PJ, Prinn, RG, and Weiss, RF
- Abstract
We reconstruct atmospheric abundances of the potent greenhouse gas span classCombining double low line inline-formula span classCombining double low line inline-formula perfluorocyclobutane, perfluorocarbon PFC-318) from measurements of in situ, archived, firn, and aircraft air samples with precisions of span classCombining double low line inline-formula reported on the SIO-14 gravimetric calibration scale. Combined with inverse methods, we found near-zero atmospheric abundances from the early 1900s to the early 1960s, after which they rose sharply, reaching 1.66ppt (parts per trillion dry-air mole fraction) in 2017. Global span classCombining double low line inline-formula span classCombining double low line inline-formula emissions rose from near zero in the 1960s to span classCombining double low line inline-formula (1span classCombining double low line inline-formula gyrspan classCombining double low line inline-formula in the late 1970s to late 1980s, then declined to span classCombining double low line inline-formula classCombining double low line inline-formula in the mid-1990s to early 2000s, followed by a rise since the early 2000s to span classCombining double low line inline-formula 2.20±0.05 Ggyrspan classCombining double low line inline-formula in 2017. These emissions are significantly larger than inventory-based emission estimates. Estimated emissions from eastern Asia rose from 0.36Ggyrspan classCombining double low line inline-formula in 2010 to 0.73Ggyrspan classCombining double low line inline-formula in 2016 and 2017, 31% of global emissions, mostly from eastern China. We estimate emissions of 0.14Ggyrspan classCombining double low line inline-formula from northern and central India in 2016 and find evidence for significant emissions from Russia. In contrast, recent emissions from northwestern Europe and Australia are estimated to be small (span classCombining double low line inline-formula % each). We suggest that emissions from China, India, an
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- 2019
14. Source apportionment of circum-Arctic atmospheric black carbon from isotopes and modeling
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Winiger, P., Barrett, T. E., Sheesley, R. J., Huang, L., Sharma, S., Barrie, L. A., Yttri, K. E., Evangeliou, N., Eckhardt, S., Stohl, A., Klimont, Z., Heyes, C., Semiletov, I. P., Dudarev, O. V., Charkin, A., Shakhova, N., Holmstrand, H., Andersson, A., Gustafsson, Ö., Winiger, P., Barrett, T. E., Sheesley, R. J., Huang, L., Sharma, S., Barrie, L. A., Yttri, K. E., Evangeliou, N., Eckhardt, S., Stohl, A., Klimont, Z., Heyes, C., Semiletov, I. P., Dudarev, O. V., Charkin, A., Shakhova, N., Holmstrand, H., Andersson, A., and Gustafsson, Ö.
- Abstract
Black carbon (BC) contributes to Arctic climate warming, yet source attributions are inaccurate due to lacking observational constraints and uncertainties in emission inventories. Year-round, isotope-constrained observations reveal strong seasonal variations in BC sources with a consistent and synchronous pattern at all Arctic sites. These sources were dominated by emissions from fossil fuel combustion in the winter and by biomass burning in the summer. The annual mean source of BC to the circum-Arctic was 39 ± 10% from biomass burning. Comparison of transport-model predictions with the observations showed good agreement for BC concentrations, with larger discrepancies for (fossil/biomass burning) sources. The accuracy of simulated BC concentration, but not of origin, points to misallocations of emissions in the emission inventories. The consistency in seasonal source contributions of BC throughout the Arctic provides strong justification for targeted emission reductions to limit the impact of BC on climate warming in the Arctic and beyond.
- Published
- 2019
15. Large Circulation Patterns Strongly Modulate Long‐Term Variability of Arctic Black Carbon Levels and Areas of Origin.
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Stathopoulos, V. K., Evangeliou, N., Stohl, A., Vratolis, S., Matsoukas, C., and Eleftheriadis, K.
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CARBON-black , *NORTH Atlantic oscillation , *ARCTIC climate , *ABSORPTION coefficients , *ATMOSPHERIC circulation , *SOOT - Abstract
Black Carbon (BC) aerosol is a major climate forcer in the Arctic. Here, we present 15 years (2001–2015) of surface observations of the aerosol absorption coefficient babs (corresponding to Equivalent BC), obtained at the Zeppelin Observatory, Ny Ålesund, Svalbard, coupled with backward transport modeling with Flexpart in order to calculate the Potential Source Contribution Function (PSCF) for BC. The observed long‐term variability superimposed on a strong annual cycle is studied as a function of large‐scale circulation patterns represented by monthly index values for the North Atlantic Oscillation (NAO) and the Scandinavian pattern (SCAN). We find a 35% increase of babs values at Zeppelin during the SCAN− phase in the winter half‐year compared to the SCAN+ phase but no significant difference in babs values between the NAO index phases. Both NAO and SCAN induce significant regional variability on the areas of origin of babs, mainly Siberia, Europe, and North America. Plain Language Summary: Here, we investigate the effect of the most important large circulation patterns for the European Arctic, namely the North Atlantic Oscillation (NAO) and Scandinavian (SCAN) patterns on the light absorbing carbon aerosol reaching the highly important area experiencing the effects of climate change as found before. We report important first time findings for an extended observation record of 15 years of aerosol light absorbing carbon, which was never been employed before as a continuous long record, and we performed the first rigorous assessment of the impact of large atmospheric circulation patterns like NAO and SCAN on the transport of black carbon aerosol expressed as the climate relevant aerosol absorption coefficient (babs) for the first time. We find a significant 35% increase in babs at Zeppelin during one of the phases of the SCAN. However, a significant regional variability induced by both NAO and SCAN phases is revealed. These findings allow a better quantified estimate of the fate of emissions over the years in the Northern Hemisphere and a better assessment of their influence in the observed BC metrics in the Artic. Key Points: An extended 15 years' observation record of Arctic aerosol light absorbing carbon is employedLarge‐scale circulation patterns appear to induce a long‐term modulation in aerosol absorption coefficient (babs) with regional featuresA 35% increase is found in babs at Zeppelin during the negative Scandinavian pattern (SCAN) phase in the 6‐month cold period compared to the positive SCAN phase [ABSTRACT FROM AUTHOR]
- Published
- 2021
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16. Source apportionment of circum-Arctic atmospheric black carbon from isotopes and modeling
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Winiger, P., primary, Barrett, T. E., additional, Sheesley, R. J., additional, Huang, L., additional, Sharma, S., additional, Barrie, L. A., additional, Yttri, K. E., additional, Evangeliou, N., additional, Eckhardt, S., additional, Stohl, A., additional, Klimont, Z., additional, Heyes, C., additional, Semiletov, I. P., additional, Dudarev, O. V., additional, Charkin, A., additional, Shakhova, N., additional, Holmstrand, H., additional, Andersson, A., additional, and Gustafsson, Ö., additional
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- 2019
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17. An intercontinental hybrid simulation experiment for the purposes of seismic assessment of a three-span R/C bridge
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Sextos A, Bousias S, Taskari O, Evangeliou N, Kwon O. S, Elnashai A. S, Di Sarno L, Palios X., Sextos, A, Bousias, S, Taskari, O, Evangeliou, N, Kwon, O. S., Elnashai, A. S., Di Sarno, L, and Palios, X.
- Subjects
bridge ,hybrid simulation ,testing - Abstract
Hybrid simulation is a promising tool that permits the integration of different laboratories in real time to undertake a set of joint experiments on individual components assembling a structural system. The components studied either analytically or experimentally can be physically distributed and thus potentially located anywhere. The same concept has also been applied for the numerical coordination of distributed sub-structures in the framework of multi-platform simulation (Kwon et al. 2007). The advantage of the hybrid experimentation approach is that it permits the use of multiple facilities and different numerical analysis packages, enabling the experimental investigation of complex physical phenomena and the concurrent numerical use of the most sophisticated constitutive laws, element types and features that each specialized software provides for each individual numerical component. Notwithstanding the major advancements made so far in hybrid experimentation, it is notable that the vast majority of such trans-laboratory campaigns has taken place within the U.S (e.g. Spencer et al. 2004). The scope of this paper therefore, is to present the recent findings and technical challenges encountered in similar hybrid experiments between E.U. and the U.S. for the study of seismic soil-structure interaction effects in bridge structures. This is an interesting case of a five-partner hybrid experimentation located in both sides of the Atlantic. The physical testing of a bearing is also deemed to be an additional challenge. The paper discusses the parameters that were found to affect the efficiency and repeatability of distributed analysis while it investigates the resilience of the procedure in cases of abrupt network failure. For this scope, the seismic response of a 100m long, three span, reinforced concrete bridge is assessed, by sub-structuring into five structural components (modules); four of them being numerically analyzed in computers located in the cities of Thessaloniki (Greece), Naples (Italy), Urbana-Champaign (U.S.), and Toronto (Canada) while the fifth module being tested in Patras (Greece). The results of the hybrid experiment as well as the implications of the parameters involved in the feasibility, robustness and repetitiveness of an intercontinental hybrid simulation are critically discussed.
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- 2014
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18. Wildfires in northern Eurasia affect the budget of black carbon in the Arctic - a 12-year retrospective synopsis (2002-2013)
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Evangeliou, N., Balkanski, Y., Hao, W. M., Petkov, A., Silverstein, R. P., Corley, R., Nordgren, B. L., Urbanski, S. P., Eckhardt, S., Stohl, A., Tunved, Peter, Crepinsek, S., Jefferson, A., Sharma, S., Nojgaard, J. K., Skov, H., Evangeliou, N., Balkanski, Y., Hao, W. M., Petkov, A., Silverstein, R. P., Corley, R., Nordgren, B. L., Urbanski, S. P., Eckhardt, S., Stohl, A., Tunved, Peter, Crepinsek, S., Jefferson, A., Sharma, S., Nojgaard, J. K., and Skov, H.
- Abstract
In recent decades much attention has been given to the Arctic environment, where climate change is happening rapidly. Black carbon (BC) has been shown to be a major component of Arctic pollution that also affects the radiative balance. In the present study, we focused on how vegetation fires that occurred in northern Eurasia during the period of 2002-2013 influenced the budget of BC in the Arctic. For simulating the transport of fire emissions from northern Eurasia to the Arctic, we adopted BC fire emission estimates developed independently by GFED3 (Global Fire Emissions Database) and FEI-NE (Fire Emission Inventory - northern Eurasia). Both datasets were based on fire locations and burned areas detected by MODIS (Moderate resolution Imaging Spectroradiometer) instruments on NASA's (National Aeronautics and Space Administration) Terra and Aqua satellites. Anthropogenic sources of BC were adopted from the MACCity (Monitoring Atmospheric Composition and Climate and megacity Zoom for the Environment) emission inventory. During the 12-year period, an average area of 250aEuro-000aEuro-km(2)aEuro-yr(-1) was burned in northern Eurasia (FEI-NE) and the global emissions of BC ranged between 8.0 and 9.5aEuro-TgaEuro-yr(-1) (FEI-NE+MACCity). For the BC emitted in the Northern Hemisphere (based on FEI-NE+MACCity), about 70aEuro-% originated from anthropogenic sources and the rest from biomass burning (BB). Using the FEI-NE+MACCity inventory, we found that 102aEuro-+/- aEuro-29aEuro-ktaEuro-yr(-1) BC was deposited in the Arctic (defined here as the area north of 67A degrees aEuro-N) during the 12 years simulated, which was twice as much as when using the MACCity inventory (56aEuro-+/- aEuro-8aEuro-ktaEuro-yr(-1)). The annual mass of BC deposited in the Arctic from all sources (FEI-NE in northern Eurasia, MACCity elsewhere) is significantly higher by about 37aEuro-% in 2009 (78 vs. 57aEuro-ktaEuro-yr(-1)) to 181aEuro-% in 2012 (153 vs. 54aEuro-ktaEuro-yr(-1)), compared to the BC
- Published
- 2016
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19. Wildfires in northern Eurasia affect the budget of black carbon in the Arctic – a 12-year retrospective synopsis (2002–2013)
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Evangeliou, N., primary, Balkanski, Y., additional, Hao, W. M., additional, Petkov, A., additional, Silverstein, R. P., additional, Corley, R., additional, Nordgren, B. L., additional, Urbanski, S. P., additional, Eckhardt, S., additional, Stohl, A., additional, Tunved, P., additional, Crepinsek, S., additional, Jefferson, A., additional, Sharma, S., additional, Nøjgaard, J. K., additional, and Skov, H., additional
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- 2016
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20. Resuspension and atmospheric transport of radionuclides due to wildfires near the Chernobyl Nuclear Power Plant in 2015: An impact assessment
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Evangeliou, N., primary, Zibtsev, S., additional, Myroniuk, V., additional, Zhurba, M., additional, Hamburger, T., additional, Stohl, A., additional, Balkanski, Y., additional, Paugam, R., additional, Mousseau, T. A., additional, Møller, A. P., additional, and Kireev, S. I., additional
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- 2016
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21. Evaluation of observed and modelled aerosol lifetimes using radioactive tracers of opportunity and an ensemble of 19 global models
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Kristiansen, N. I., primary, Stohl, A., additional, Olivié, D. J. L., additional, Croft, B., additional, Søvde, O. A., additional, Klein, H., additional, Christoudias, T., additional, Kunkel, D., additional, Leadbetter, S. J., additional, Lee, Y. H., additional, Zhang, K., additional, Tsigaridis, K., additional, Bergman, T., additional, Evangeliou, N., additional, Wang, H., additional, Ma, P.-L., additional, Easter, R. C., additional, Rasch, P. J., additional, Liu, X., additional, Pitari, G., additional, Di Genova, G., additional, Zhao, S. Y., additional, Balkanski, Y., additional, Bauer, S. E., additional, Faluvegi, G. S., additional, Kokkola, H., additional, Martin, R. V., additional, Pierce, J. R., additional, Schulz, M., additional, Shindell, D., additional, Tost, H., additional, and Zhang, H., additional
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- 2016
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22. Supplementary material to "Wildfires in Northern Eurasia affect the budget of black carbon in the Arctic. A 12-year retrospective synopsis (2002–2013)."
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Evangeliou, N., primary, Balkanski, Y., additional, Hao, W. M., additional, Petkov, A., additional, Silverstein, R. P., additional, Corley, R., additional, Nordgren, B. L., additional, Urbanski, S. P., additional, Eckhardt, S., additional, Stohl, A., additional, Tunved, P., additional, Crepinsek, S., additional, Jefferson, A., additional, Sharma, S., additional, Nøjgaard, J. K., additional, and Skov, H., additional
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- 2016
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23. POC and particulate 234Th export fluxes estimated using 234Th/238U disequilibrium in an enclosed Eastern Mediterranean region (Saronikos Gulf and Elefsis Bay, Greece) in seasonal scale
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Evangeliou, N. Florou, H. Scoullos, M.
- Abstract
Activity concentrations of the naturally occurring, short-lived and highly particle-reactive radionuclide tracer 234Th in the dissolved and particulate phase were determined at 7 shallow-water stations (maximum depths: 30 (S.1 and S.2), 65 (S.3), 97 (S.5), 105 (S.6) and 220m (S.4 and S.7) in Saronikos Gulf and Elefsis Bay (central Aegean Sea, Greece) during 3 seasonal cruises (summer 2008, autumn 2008 and winter 2009) to assess the time scales of the dynamics and the depositional fate of particulate matter (POC, particulate 234Th). For that reason, in situ filtrating systems were deployed in several depths of the water column consisting of GF/A disc prefilters to scavenge particulate fraction of 234Th and organic carbon and impregnated cartridges to adsorb dissolved 234Th. The obtained data showed average particulate 234Th activity concentrations of 3.7±0.4Bqm-3 in summer, 2.1±0.2Bqm-3 in autumn and 2.4±0.2Bqm-3 in winter. The respective average dissolved 234Th activity concentrations were 30.1±2.8Bqm-3 in summer, 30.2±2.9Bqm-3 in autumn and 27.4±3.0Bqm-3 in winter. The activity ratios of total 234Th and its long-lived conservative parent 238U were below unity in most of the stations indicating radioactive disequilibrium throughout the water column, thus very dynamic trace-metal scavenging and particle export from the water column. These profiles (234Th and 238U) were used to estimate the export fluxes and scavenging rates of 234Th, as well as their residence times in the water column. The average cumulative export fluxes of particulate 234Th were estimated to be 33±4Bqm-2d-1 in summer, 35±5Bqm-2d-1 in autumn and 45±6Bqm-2d-1 in winter, whereas the respective average cumulative scavenging rates of dissolved 234Th were 39±5, 33±5 and 50±7Bqm-2d-1. Moreover, the cumulative average residence times of 234Th were 25±4d in summer, 45±6d in autumn and 64±7d in winter 2009 for the dissolved fraction and 4±1, 3±1 and 4±1d for the particulate one, respectively. POC/AThp ratio profiles decreased versus depth showing a variety of marine processes, such as loss of POC due to dissolution after biological activity, impact of minerals in particle sinking and microbial remineralization. Average cumulative export fluxes of POC were 162±18mmolm-2d-1 in summer, 107±19mmolm-2d-1 in autumn and 157±25mmolm-2d-1 in winter 2009. The seasonal data of POC fluxes certified the existence of phytoplankton bloom in winter for Saronikos Gulf. In addition, after evaluating the maxima of POC fluxes in Elefsis Bay (a small embayment in northern Saronikos Gulf) during summer, potential bloom of phytoplankton also concluded; this approach is in agreement with previous data of the same area. Finally, the elevated POC concentrations and fluxes in the region certify that the Gulf is still one of the most organic polluted in the Mediterranean Sea. © 2011.
- Published
- 2011
24. Evaluation of observed and modelled aerosol lifetimes using radioactive tracers of opportunity and an ensemble of 19 global models
- Author
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Kristiansen, N. I., primary, Stohl, A., additional, Olivié, D. J. L., additional, Croft, B., additional, Søvde, O. A., additional, Klein, H., additional, Christoudias, T., additional, Kunkel, D., additional, Leadbetter, S. J., additional, Lee, Y. H., additional, Zhang, K., additional, Tsigaridis, K., additional, Bergman, T., additional, Evangeliou, N., additional, Wang, H., additional, Ma, P.-L., additional, Easter, R. C., additional, Rasch, P. J., additional, Liu, X., additional, Pitari, G., additional, Di Genova, G., additional, Zhao, S. Y., additional, Balkanski, Y., additional, Bauer, S. E., additional, Faluvegi, G. S., additional, Kokkola, H., additional, Martin, R. V., additional, Pierce, J. R., additional, Schulz, M., additional, Shindell, D., additional, Tost, H., additional, and Zhang, H., additional
- Published
- 2015
- Full Text
- View/download PDF
25. A preliminary study of particle dynamics in the water column of Saronikos Gulf, Greece, by using Th-234/U-238 disequilibrium approach
- Author
-
Evangeliou, N. Florou, H. Scoullos, M.
- Abstract
In the present study the particle export flux in the water column of 3 sampling stations (one of them near the pipeline outfall of the Waste Water Treatment Plant-WWTP of Psitalia) in the Eastern Saronikos gulf, Central Greece, is investigated based on the disequilibrium ratio of 234Th with its parent 238U. This approach is based on direct measurements of the activity concentrations of 234Th and calculated ones of 238U from the respective salinity measurements. From the derived results, the values of the activity concentrations of particulate and dissolved fraction of 234Th in the surface layer of the studied area range from 2.7 ± 1.4 to 3.8 ± 1.8 Bq m -3 and 13.2 ± 1.4 to 28.2 ± 1.9 Bq m 3 respectively, which educe fluctuation according to the station environmental features. Regarding the vertical distribution of radionuclides, the observed profile curves from the 3 sampling stations follow the same pattern of dispersion in the water column. However, the calculated export flux (sinking rate) of particles associated with 234Th results to a wide range of values depending on the sampling station. From the calculated residence times in the 3 stations, the station near the WWTP shows the longer residence time for the dissolved fraction, which is attributed to the sewage outflow. Besides, total suspended matter (TSM) and dissolved organic carbon (DOC) have been analyzed in the samples and the correlation coefficients with the particulate and dissolved 234Th have been calculated on the basis of the relation of 234Th cycling with particulate matter and organic substances. © 2010 Desalination Publications.
- Published
- 2010
26. Temporal and spatial distribution of 137Cs in Eastern Mediterranean Sea. Horizontal and vertical dispersion in two regions
- Author
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Evangeliou, N. Florou, H. Bokoros, P. Scoullos, M.
- Abstract
Caesium-137 activity concentration in the water columns of the Gulf of Patras (Central Greece) and the North-Eastern Aegean Sea (easterward to Lemnos Island) was investigated in selected sampling stations during the period September 2004-June 2006. The methodology followed was based on the sorption of caesium (Cs) on cotton wound cartridge filters impregnated by Cu2[Fe(CN)6] via in-situ pumping. In terms of the horizontal and vertical records, the activity concentrations of 137Cs in the Gulf of Patras ranged between 1.2 and 6.7 Bq m-3, depending on the sampling period and the prevailing physicochemical regime at the sampling station. The general pattern of the decreased activity concentrations of 137Cs with increasing depth was reversed in the Gulf of Patras during the cold period attributed to the prevailing advective processes of the area. The activity concentrations of 137Cs in the North-Eastern Aegean Sea ranged from 2.6 to 12.8 Bq m-3, whereas significant stratified curves were observed during the warm period and also, in one station during the cold period. In terms of temporal variation, the discharges in the Gulf of Patras resulted in enhanced levels of 137Cs, whereas in the North Aegean Sea the incoming water masses form the Black Sea had an apparent influence throughout the year by increasing the 137Cs levels, hence presenting a weak seasonal variation. Comparing the two studied areas, one could say that the North Aegean Sea, as an open sea environment, presented higher concentrations due to the influence of the Black Sea water masses. The estimated inventories of 137Cs in the Gulf of Patras ranged 0.25 ± 0.03-0.79 ± 0.03 kBq m-2, whereas in the North-Eastern Aegean Sea they ranged 0.33 ± 0.02-0.92 ± 0.03 kBq m-2. © 2009 Elsevier Ltd. All rights reserved.
- Published
- 2009
27. The concentration of 137Cs in the surface of the Greek marine environment
- Author
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Florou, H., Nicolaou, G., and Evangeliou, N.
- Published
- 2010
- Full Text
- View/download PDF
28. Simulations of the transport and deposition of <sup>137</sup>Cs over Europe after the Chernobyl Nuclear Power Plant accident: influence of varying emission-altitude and model horizontal and vertical resolution
- Author
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Evangeliou, N., primary, Balkanski, Y., additional, Cozic, A., additional, and Møller, A. P., additional
- Published
- 2013
- Full Text
- View/download PDF
29. Supplementary material to "Simulations of the transport and deposition of 137Cs over Europe after the Chernobyl NPP accident: influence of varying emission-altitude and model horizontal and vertical resolution"
- Author
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Evangeliou, N., primary, Balkanski, Y., additional, Cozic, A., additional, and Møller, A. P., additional
- Published
- 2013
- Full Text
- View/download PDF
30. Simulations of the transport and deposition of 137Cs over Europe after the Chernobyl NPP accident: influence of varying emission-altitude and model horizontal and vertical resolution
- Author
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Evangeliou, N., primary, Balkanski, Y., additional, Cozic, A., additional, and Møller, A. P., additional
- Published
- 2013
- Full Text
- View/download PDF
31. Erratum to “The concentration of 137Cs in the surface of the Greek marine environment”
- Author
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Florou, H., primary, Nicolaou, G., additional, and Evangeliou, N., additional
- Published
- 2012
- Full Text
- View/download PDF
32. Distribution of low-level natural radioactivity in a populated marine region of the easternMediterranean Sea
- Author
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Evangeliou, N., primary, Florou, H., additional, and Kritidis, P., additional
- Published
- 2012
- Full Text
- View/download PDF
33. Distribution of natural radioactivity in sediment cores from Amvrakikos Gulf (Western Greece) as a part of IAEA's campaign in the Adriatic and Ionian Seas
- Author
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Tsabaris, C., primary, Evangeliou, N., additional, Fillis-Tsirakis, E., additional, Sotiropoulou, M., additional, Patiris, D. L., additional, and Florou, H., additional
- Published
- 2011
- Full Text
- View/download PDF
34. Design and experimental evaluation of an innovative SMA-based tendon-driven redundant endoscopic robotic surgical tool
- Author
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Giataganas, P., primary, Evangeliou, N., additional, Koveos, Y., additional, Kelasidi, E., additional, and Tzes, A., additional
- Published
- 2011
- Full Text
- View/download PDF
35. A preliminary study of particle dynamics in the water column of Saronikos Gulf, Greece, by using Th-234/U-238 disequilibrium approach
- Author
-
Evangeliou, N., primary, Florou, H., additional, and Scoullos, M., additional
- Published
- 2010
- Full Text
- View/download PDF
36. Evaluation of observed and modelled aerosol lifetimes using radioactive tracers of opportunity and an ensemble of 19 global models.
- Author
-
Kristiansen, N. I., Stohl, A., Olivié, D. J. L., Croft, B., Søvde, O. A., Klein, H., Christoudias, T., Kunkel, D., Leadbetter, S. J., Lee, Y. H., Zhang, K., Tsigaridis, K., Bergman, T., Evangeliou, N., Wang, H., Ma, P.-L., Easter, R. C., Rasch, P. J., Liu, X., and Pitari, G.
- Abstract
Aerosols have important impacts on air quality and climate, but the processes affecting their removal from the atmosphere are not fully understood and are poorly constrained by observations. This makes modelled aerosol lifetimes uncertain. In this study, we make use of an observational constraint on aerosol lifetimes provided by radionuclide measurements and investigate the causes of differences within a set of global models. During the Fukushima Dai-Ichi nuclear power plant accident of March 2011, the radioactive isotopes cesium-137 (
137 Cs) and xenon-133 (133 Xe) were released in large quantities. Cesium attached to particles in the ambient air, approximately according to their available aerosol surface area.137 Cs size distribution measurements taken close to the power plant suggested that accumulation-mode (AM) sulphate aerosols were the main carriers for the cesium. Hence,137 Cs can be used as a proxy tracer for the AM sulphate aerosol's fate in the atmosphere. In contrast, the noble gas133 Xe behaves almost like a passive transport tracer. Global surface measurements of the two radioactive isotopes taken over several months after the release allow the derivation of a lifetime of the carrier aerosol. We compare this to the lifetimes simulated by 19 different atmospheric transport models initialized with identical emissions of137 Cs that were assigned to an aerosol tracer with each model's default properties of AM sulphate, and133 Xe emissions that were assigned to a passive tracer. We investigate to what extent the modelled sulphate tracer can reproduce the measurements, especially with respect to the observed loss of aerosol mass with time. Modelled37 Cs and133 Xe concentrations sampled at the same location and times as station measurements allow a direct comparison between measured and modelled aerosol lifetime. The e-folding lifetime τe , calculated from station measurement data taken between two and nine weeks after the start of the emissions, is 14.3 days (95% confidence interval 13.1-15.7 days). The equivalent modelled τe lifetimes have a large spread, varying between 4.8 and 26.7 days with a model median of 9.4±2.3 days, indicating too fast removal in most models. Because sufficient measurement data were only available from about two weeks after the release, the estimated lifetimes apply to aerosols that have undergone long-range transport, i.e. not for freshly emitted aerosol. However, modelled instantaneous lifetimes show that the initial removal in the first two weeks was quicker (lifetimes between 1-5 days) due to the emissions occurring at low altitudes and co-location of the fresh plume with strong precipitation. Deviations between measured and modelled aerosol lifetimes are largest for the northernmost stations and at later time periods, suggesting that models do not transport enough of the aerosol towards the Arctic. The models underestimate passive tracer (133 Xe) concentrations in the Arctic as well but to a smaller extent than for the aerosol (137 Cs) tracer. This indicates that in addition to too fast aerosol removal in the models, errors in simulated atmospheric transport towards the Arctic in most models also contribute to the Arctic aerosol underestimates. [ABSTRACT FROM AUTHOR]- Published
- 2015
- Full Text
- View/download PDF
37. Simulations of the transport and deposition of 137Cs over Europe after the Chernobyl Nuclear Power Plant accident: influence of varying emission-altitude and model horizontal and vertical resolution.
- Author
-
Evangeliou, N., Balkanski, Y., Cozic, A., and Møller, A. P.
- Subjects
ATMOSPHERIC radioactivity ,CHERNOBYL Nuclear Accident, Chornobyl, Ukraine, 1986 ,SIMULATION methods & models ,TRANSPORT theory ,ATMOSPHERIC chemistry ,RADIOACTIVE tracers ,ATMOSPHERIC deposition - Abstract
The coupled model LMDZORINCA has been used to simulate the transport, wet and dry deposition of the radioactive tracer
137 Cs after accidental releases. For that reason, two horizontal resolutions were deployed and used in the model, a regular grid of 2.5° × 1.27°, and the same grid stretched over Europe to reach a resolution of 0.66° × 0.51°. The vertical dimension is represented with two different resolutions, 19 and 39 levels respectively, extending up to the mesopause. Four different simulations are presented in this work; the first uses the regular grid over 19 vertical levels assuming that the emissions took place at the surface (RG19L(S)), the second also uses the regular grid over 19 vertical levels but realistic source injection heights (RG19L); in the third resolution the grid is regular and the vertical resolution 39 levels (RG39L) and finally, it is extended to the stretched grid with 19 vertical levels (Z19L). The model is validated with the Chernobyl accident which occurred in Ukraine (ex-USSR) on 26 May 1986 using the emission inventory from Brandt et al. (2002). This accident has been widely studied since 1986, and a large database has been created containing measurements of atmospheric activity concentration and total cumulative deposition for137 Cs from most of the European countries. According to the results, the performance of the model to predict the transport and deposition of the radioactive tracer was efficient and accurate presenting low biases in activity concentrations and deposition inventories, despite the large uncertainties on the intensity of the source released. The best agreement with observations was obtained using the highest horizontal resolution of the model (Z19L run). The model managed to predict the radioactive contamination in most of the European regions (similar to De Cort et al., 1998), and also the arrival times of the radioactive fallout. As regards to the vertical resolution, the largest biases were obtained for the 39 layers run due to the increase of the levels in conjunction with the uncertainty of the source term. Moreover, the ecological half-life of137 Cs in the atmosphere after the accident ranged between 6 and 9 days, which is in good accordance to what previously reported and in the same range with the recent accident in Japan. The high response of LMDZORINCA model for137 Cs reinforces the importance of atmospheric modelling in emergency cases to gather information for protecting the population from the adverse effects of radiation. [ABSTRACT FROM AUTHOR]- Published
- 2013
- Full Text
- View/download PDF
38. Simulations of the transport and deposition of 137Cs over Europe after the Chernobyl NPP accident: influence of varying emission-altitude and model horizontal and vertical resolution.
- Author
-
Evangeliou, N., Balkanski, Y., Cozic, A., and Møller, A. P.
- Abstract
The coupled model LMDzORINCA has been used to simulate the transport, wet and dry deposition of the radioactive tracer
137 Cs after accidental releases. For that reason, two horizontal resolutions were deployed and used in the model, a regular grid of 2.5° x 1.25°, and the same grid stretched over Europe to reach a resolution of 0.45° x 0.51°. The vertical dimension is represented with two different resolutions, 19 and 39 levels, respectively, extending up to mesopause. Four different simulations are presented in this work; the first uses the regular grid over 19 vertical levels assuming that the emissions took place at the surface (RG19L(S)), the second also uses the regular grid over 19 vertical levels but realistic source injection heights (RG19L); in the third resolution the grid is regular and the vertical resolution 39 vertical levels (RG39L) and finally, it is extended to the stretched grid with 19 vertical levels (Z19L). The best choice for the model validation was the Chernobyl accident which occurred in Ukraine (ex-USSR) on 26 May 1986. This accident has been widely studied since 1986, and a large database has been created containing measurements of atmospheric activity concentration and total cumulative deposition for137 Cs from most of the European countries. According to the results, the performance of the model to predict the transport and deposition of the radioactive tracer was efficient and accurate presenting low biases in activity concentrations and deposition inventories, despite the large uncertainties on the intensity of the source released. However, the best agreement with observations was obtained using the highest horizontal resolution of the model (Z19L run). The model managed to predict the radioactive contamination in most of the European regions (similar to Atlas), and also the arrival times of the radioactive fallout. As regards to the vertical resolution, the largest biases were obtained for the 39 layers run due to the increase of the levels in conjunction with the uncertainty of the source term. Moreover, the ecological half-life of137 Cs in the atmosphere after the accident ranged between 6 and 9 days, which is in good accordance to what previously reported and in the same range with the recent accident in Japan. The high response of LMDzORINCA model for137 Cs reinforces the importance of atmospheric modeling in emergency cases to gather information for protecting the population from the adverse effects of radiation. [ABSTRACT FROM AUTHOR]- Published
- 2013
- Full Text
- View/download PDF
39. Distribution of natural radioactivity in sediment cores from Amvrakikos Gulf (Western Greece) as a part of IAEA's campaign in the Adriatic and Ionian Seas.
- Author
-
Tsabaris, C., Evangeliou, N., Fillis-Tsirakis, E., Sotiropoulou, M., Patiris, D. L., and Florou, H.
- Subjects
RADIOACTIVITY ,VERTICAL distribution (Aquatic biology) ,GAMMA ray spectrometry ,GERMANIUM ,NUMERICAL calculations ,DATABASES - Abstract
The vertical distribution of natural radionuclides (232Th decay, 238U decay, 40K and 210Pb) was assessed in sediment cores collected from the Amvrakikos Gulf, (Ionian Sea, Western Greece). Two collection stations were selected, the first at the western part of the Gulf near Preveza Strait (13A station) and the other near the centre of the Gulf (13B station). Activity concentrations were measured by means of gamma-ray spectrometry using high-purity germanium (HPGe) detectors installed at two national laboratories. The activity concentration of 226Ra was found in a range from 10 to 20 Bq kg−1, while the activity concentration of 222Rn daughters (214Pb, 214Bi) ranged from 6 to 20 Bq kg−1. The activity concentration of 228Ac varied from 20 to 28 Bq kg−1, while 220Rn daughters (212Pb, 208Tl) from 7 to 35 Bq kg−1. As concerns 40K and 210Pb, their activities varied from 400 to 830 Bq kg−1 and from 11 to 360 Bq kg−1, respectively. Also, the data of 210Pb were utilised in the calculations of the sedimentation rate along the sediment cores. Both locations were characterised by a consistent pattern with the average rates of 0.55 ± 0.02 and 0.32 ± 0.02 cm y−1, corresponding to 13A and 13B stations, respectively. Finally, the measurements constituted the basis of the first reported database concerning the radiological condition of the Gulf and which can be reclaimed as reference values in future monitoring studies. [ABSTRACT FROM AUTHOR]
- Published
- 2012
- Full Text
- View/download PDF
40. Temporal and spatial distribution of 137Cs in Eastern Mediterranean Sea. Horizontal and vertical dispersion in two regions
- Author
-
Evangeliou, N., Florou, H., Bokoros, P., and Scoullos, M.
- Subjects
- *
CESIUM isotopes , *RADIOISOTOPES & the environment , *SEA water analysis , *ENVIRONMENTAL chemistry - Abstract
Abstract: Caesium-137 activity concentration in the water columns of the Gulf of Patras (Central Greece) and the North-Eastern Aegean Sea (easterward to Lemnos Island) was investigated in selected sampling stations during the period September 2004–June 2006. The methodology followed was based on the sorption of caesium (Cs) on cotton wound cartridge filters impregnated by Cu2[Fe(CN)6] via in-situ pumping. In terms of the horizontal and vertical records, the activity concentrations of 137Cs in the Gulf of Patras ranged between 1.2 and 6.7Bqm−3, depending on the sampling period and the prevailing physicochemical regime at the sampling station. The general pattern of the decreased activity concentrations of 137Cs with increasing depth was reversed in the Gulf of Patras during the cold period attributed to the prevailing advective processes of the area. The activity concentrations of 137Cs in the North-Eastern Aegean Sea ranged from 2.6 to 12.8Bqm−3, whereas significant stratified curves were observed during the warm period and also, in one station during the cold period. In terms of temporal variation, the discharges in the Gulf of Patras resulted in enhanced levels of 137Cs, whereas in the North Aegean Sea the incoming water masses form the Black Sea had an apparent influence throughout the year by increasing the 137Cs levels, hence presenting a weak seasonal variation. Comparing the two studied areas, one could say that the North Aegean Sea, as an open sea environment, presented higher concentrations due to the influence of the Black Sea water masses. The estimated inventories of 137Cs in the Gulf of Patras ranged 0.25±0.03–0.79±0.03kBqm−2, whereas in the North-Eastern Aegean Sea they ranged 0.33±0.02–0.92±0.03kBqm−2. [Copyright &y& Elsevier]
- Published
- 2009
- Full Text
- View/download PDF
41. Fire evolution in the radioactive forests of Ukraine and Belarus: Future risks for the population and the environment
- Author
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Evangeliou, N., Balkanski, Y., Cozic, A., Hao, W. M., Mouillot, F., Thonicke, K., Paugam, R., Zibtsev, S., Mousseau, T. A., Wang, R., Poulter, B., Petkov, A., Yue, C., Cadule, P., Koffi, B., Johannes Kaiser, Møller, A. P., and Classen, A. T.
42. Mortality induced by PM2.5 exposure following the 1783 Laki eruption using reconstructed meteorological fields.
- Author
-
Balkanski, Y., Menut, L., Garnier, E., Wang, R., Evangeliou, N., Jourdain, S., Eschstruth, C., Vrac, M., and Yiou, P.
- Abstract
The 1783-1784 Laki eruption provides a natural experiment to evaluate the performance of chemistry-transport models in predicting the health impact of air particulate pollution. There are few existing daily meteorological observations during the second part of the 18
th century. Hence, creating reasonable climatological conditions for such events constitutes a major challenge. We reconstructed meteorological fields for the period 1783-1784 based on a technique of analogues described in the Methods. Using these fields and including detailed chemistry we describe the concentrations of sulphur (SO2 /SO4 ) that prevail over the North Atlantic, the adjoining seas and Western Europe during these 2 years. To evaluate the model, we analyse these results through the prism of two datasets contemporary to the Laki period: • The date of the first appearance of ‘dry fogs’ over Europe, • The excess mortality recorded in French parishes over the period June-September 1783. The sequence of appearances of the dry fogs is reproduced with a very-high degree of agreement to the first dataset. High concentrations of SO2 /SO4 are simulated in June 1783 that coincide with a rapid rise of the number of deceased in French parishes records. We show that only a small part of the deceased of the summer of 1783 can be explained by the present-day relationships between PM2.5 and relative risk. The implication of this result is that other external factors such as the particularly warm summer of 1783, and the lack of health care at the time, must have contributed to the sharp increase in mortality over France recorded from June to September 1783. [ABSTRACT FROM AUTHOR]- Published
- 2018
- Full Text
- View/download PDF
43. The concentration of 137Cs in the surface of the Greek marine environment
- Author
-
Florou, H., Nicolaou, G., and Evangeliou, N.
- Subjects
- *
CESIUM isotopes , *SURFACE chemistry , *MARINE ecology , *CHERNOBYL Nuclear Accident, Chornobyl, Ukraine, 1986 , *BACKGROUND radiation , *TRANSPORT theory - Abstract
Abstract: The radiological status of the Greek marine environment, prior to the Chernobyl accident, was characterized mainly by the fallout from nuclear weapon tests. However, the release of radioactivity into the environment from the accident in the Chernobyl Nuclear Power Plant and its deposition in the Greek marine environment resulted in an increase of the 137Cs activity concentration by approximately one order of magnitude. In addition, the direct transport of radiocaesium into the North Aegean Sea has been further influenced by the late impact of the Chernobyl accident on the Greek marine environment, related to the transfer of 137Cs, mainly through the Dnieper but also the Danube rivers, to the Black Sea and further to the North Aegean Sea through the Straits of Dardanelles. The aim of this work is to provide a present day picture of the geographic variation of the concentration of 137Cs in the surface layer of the Greek marine environment and hence, to evaluate the annual committed effective dose delivered to humans through the ingestion pathway from marine sources. [Copyright &y& Elsevier]
- Published
- 2010
- Full Text
- View/download PDF
44. Intercontinental Hybrid Simulation for the Assessment of a Three-Span R/C Highway Overpass
- Author
-
Stathis Bousias, Olympia Taskari, Luigi Di Sarno, Nikos Evangeliou, Anastasios Sextos, Oh-Sung Kwon, Amr S. Elnashai, Bousias, S., Sextos, A., Kwon, O. -S., Taskari, O., Elnashai, A., Evangeliou, N., Di Sarno, L., Bousias, S, Sextos, A, Kwon, O, Taskari, O, Elnashai, A, and Evangeliou, N
- Subjects
021110 strategic, defence & security studies ,Engineering ,business.industry ,Hybrid testing ,Testing ,0211 other engineering and technologies ,020101 civil engineering ,02 engineering and technology ,Building and Construction ,Structural engineering ,Seismic Assessment ,Geotechnical Engineering and Engineering Geology ,Span (engineering) ,Bridge (interpersonal) ,Bridges ,0201 civil engineering ,Seismic assessment ,business ,Bridge ,Hybrid Testing ,Simulation ,Civil and Structural Engineering - Abstract
This paper presents hybrid simulations of a three-span R/C bridge among EU, US, and Canada. The tests involved partners located on both sides of the Atlantic with each one assigned a numerical or a physical module of the substructured bridge. Despite the network latency in linking remote sites located on the two sides of the Atlantic the intercontinental hybrid simulation was accomplished and repeated successfully, highlighting the efficiency, and repetitiveness of the approach. Adaptations, challenges, and limitations are discussed, focusing on the implications of network communication latency, the insensitivity of the sub-structuring arrangement, and the accuracy of the results obtained.
- Published
- 2019
45. Changes in black carbon emissions over Europe due to COVID-19 lockdowns
- Author
-
N. Evangeliou, S. M. Platt, S. Eckhardt, C. Lund Myhre, P. Laj, L. Alados-Arboledas, J. Backman, B. T. Brem, M. Fiebig, H. Flentje, A. Marinoni, M. Pandolfi, J. Yus-Dìez, N. Prats, J. P. Putaud, K. Sellegri, M. Sorribas, K. Eleftheriadis, S. Vratolis, A. Wiedensohler, A. Stohl, Institute for Atmospheric and Earth System Research (INAR), European Commission, Pandolfi, Marco, Pandolfi, Marco [0000-0002-7493-7213], 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 ), Université Grenoble Alpes (UGA), Laboratoire de Météorologie Physique (LaMP), Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Clermont Auvergne (UCA), Evangeliou, N. [0000-0001-7196-1018], Eckhardt, S. [0000-0001-6958-5375], Lund Myhre, C. [0000-0003-3587-5926], Alados Arboledas, L. [0000-0003-3576-7167], Backman, J. [0000-0002-4444-8777], Brem, B. T. [0000-0001-6211-2815], Fiebig, M. [0000-0002-3380-3470], Marinoni, A. [0000-0002-6580-7126], Yus Díez, J. [0000-0002-8124-1492], Sorribas, M. [0000-0003-2131-9021], Eleftheriadis, K. [0000-0003-2265-4905], Wiedensohler, A. [0000-0001-8298-491X], Stohl, A. [0000-0002-2524-5755], Research Council of Norway, and European Commission (EC)
- Subjects
Atmospheric Science ,Coronavirus disease 2019 (COVID-19) ,010504 meteorology & atmospheric sciences ,Pollutant emissions ,Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) ,Black carbon emissions ,010501 environmental sciences ,050905 science studies ,114 Physical sciences ,01 natural sciences ,7. Clean energy ,World health ,lcsh:Chemistry ,Black carbon ,REANALYSIS ,Bayesian inversion ,EAST-ASIA ,COVID-19 lockdowns ,Effective treatment ,China ,Socioeconomics ,Air quality index ,1172 Environmental sciences ,Carbon emissions ,0105 earth and related environmental sciences ,TREND ,Pandemic ,SARS-CoV-2 ,05 social sciences ,ATTRIBUTION ,COVID-19 ,LIGHT-ABSORPTION ,lcsh:QC1-999 ,TRANSPORT ,3. Good health ,Europe ,Geography ,lcsh:QD1-999 ,[SDU]Sciences of the Universe [physics] ,13. Climate action ,Air quality ,0509 other social sciences ,lcsh:Physics ,PARTICLE DISPERSION MODEL - Abstract
This study has been supported by the Research Council of Norway (project ID: 275407, COMBAT - Quantification of Global Ammonia Sources constrained by a Bayesian Inversion Technique). Nikolaos Evangeliou and Sabine Eckhardt received funding from the Arctic Monitoring & Assessment Programme (AMAP). John Backman was supported by the Academy of Finland project Novel Assessment of Black Carbon in the Eurasian Arctic: From Historical Concentrations and Sources to Future Climate Impacts (NABCEA; project no. 296302), the Academy of Finland Centre of Excellence programme (project no. 307331) and COST Action CA16109 Chemical On-Line cOmpoSition and Source Apportionment of fine aerosoL, COLOSSAL. The research leading to the ACTRIS measurements has received funding from the European Union's Horizon 2020 Research And Innovation programme (grant agreement no. 654109) and the Cloudnet project (European Union contract EVK2-2000-00611)., All measurement data and model outputs used for the present publication are publicly available and can be downloaded from https://doi.org/10.21336/gen.b5vj-sn33 (Evangeliou et al., 2020) or upon request to the corresponding author. All prior emission datasets are also available for download. ECLIPSE emissions can be obtained from http://www.iiasa.ac.at/web/home/research/researchPrograms/air/Global_emissions.html (Klimont et al., 2017), EDGAR version HTAP_V2.2 from http://edgar.jrc.ec.europa.eu/methodology.php# (Janssens-Maenhout et al., 2015), ACCMIP version 5 from http://accent.aero.jussieu.fr/ACCMIP_metadata.php (Lamarque et al., 2010) and PKU from http://inventory.pku.edu.cn (Peking University, 2021). FLEXPART is publicly available and can be downloaded from https://www.flexpart.eu (Pisso et al., 2019) and FLEXINVERT+ from https://flexinvert.nilu.no (Thompson and Stohl, 2014). MERRA-2 reanalysis data can be obtained from https://disc.gsfc.nasa.gov (NASA Earth Data, 2021) and AERONET measurements from https://aeronet.gsfc.nasa.gov (Holben et al., 1998)., The supplement related to this article is available online at: https://doi.org/10.5194/acp-21-2675-2021-supplement., Following the emergence of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) responsible for COVID-19 in December 2019 in Wuhan (China) and its spread to the rest of the world, the World Health Organization declared a global pandemic in March 2020. Without effective treatment in the initial pandemic phase, social distancing and mandatory quarantines were introduced as the only available preventative measure. In contrast to the detrimental societal impacts, air quality improved in all countries in which strict lockdowns were applied, due to lower pollutant emissions. Here we investigate the effects of the COVID-19 lockdowns in Europe on ambient black carbon (BC), which affects climate and damages health, using in situ observations from 17 European stations in a Bayesian inversion framework. BC emissions declined by 23 kt in Europe (20 % in Italy, 40 % in Germany, 34 % in Spain, 22 % in France) during lockdowns compared to the same period in the previous 5 years, which is partially attributed to COVID-19 measures. BC temporal variation in the countries enduring the most drastic restrictions showed the most distinct lockdown impacts. Increased particle light absorption in the beginning of the lockdown, confirmed by assimilated satellite and remote sensing data, suggests residential combustion was the dominant BC source. Accordingly, in central and Eastern Europe, which experienced lower than average temperatures, BC was elevated compared to the previous 5 years. Nevertheless, an average decrease of 11 % was seen for the whole of Europe compared to the start of the lockdown period, with the highest peaks in France (42 %), Germany (21 %), UK (13 %), Spain (11 %) and Italy (8 %). Such a decrease was not seen in the previous years, which also confirms the impact of COVID-19 on the European emissions of BC., Research Council of Norway, rctic Monitoring & Assessment Programme (AMAP)., Academy of Finland project Novel Assessment of Black Carbon in the Eurasian Arctic: From Historical Concentrations and Sources to Future Climate Impacts (NABCEA) 296302, Academy of Finland 307331, European Cooperation in Science and Technology (COST) CA16109, European Union's Horizon 2020 Research And Innovation programme 654109, Cloudnet project European Union EVK2-2000-00611
- Published
- 2021
46. Erratum to “The concentration of 137Cs in the surface of the Greek marine environment”
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Florou, H., Nicolaou, G., and Evangeliou, N.
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- 2012
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47. Rapid decline of carbon monoxide emissions in the Fenwei Plain in China during the three-year Action Plan on defending the blue sky.
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Jia M, Jiang F, Evangeliou N, Eckhardt S, Huang X, Ding A, and Stohl A
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- Carbon Monoxide, Bayes Theorem, China, Air Pollution prevention & control, Air Pollution analysis, Air Pollutants analysis
- Abstract
The Fenwei Plain is one of China's most polluted regions, with poor atmospheric dispersion conditions and an outdated energy structure. After implementing multiple policies in recent years, significant reductions in air pollutant concentrations were observed. In this study, based on the Lagrangian-Bayesian inversion framework FLEXINVERT, we constructed a variable resolution inversion system focusing on the Fenwei Plain and inferred the carbon monoxide (CO) emissions using in-situ atmospheric CO observations from April 2014 to March 2020. We analyzed the spatiotemporal variations of the CO emissions and discussed their causes, especially the effect of the "Three-year Action Plan on Defending the Blue Sky" (TAPDBS). Before the policy, CO emissions temporarily increased, and the overall decrease in CO emissions per unit of Gross Domestic Product (GDP) slowed down. When the policy was implemented, CO emission fluxes declined sharply, with an average drop of 28%, accompanied by an even higher 37% decrease of CO emission per GDP. The reasons for the decline in CO emissions in Shanxi, Shaanxi and Henan are diverse. The decrease in energy intensity is the reason for CO emission reduction in Shannxi and Henan province but not in Shanxi province. This research fills the gap in emission information in recent years and confirms that TAPDBS has brought a breakthrough in both economic development and air quality protection in the Fenwei Plain., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier Ltd. All rights reserved.)
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- 2023
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48. Occurrence and backtracking of microplastic mass loads including tire wear particles in northern Atlantic air.
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Goßmann I, Herzke D, Held A, Schulz J, Nikiforov V, Georgi C, Evangeliou N, Eckhardt S, Gerdts G, Wurl O, and Scholz-Böttcher BM
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- Plastics chemistry, Environmental Monitoring, Polypropylenes, Microplastics, Water Pollutants, Chemical analysis
- Abstract
Few studies report the occurrence of microplastics (MP), including tire wear particles (TWP) in the marine atmosphere, and little data is available regarding their size or sources. Here we present active air sampling devices (low- and high-volume samplers) for the evaluation of composition and MP mass loads in the marine atmosphere. Air was sampled during a research cruise along the Norwegian coast up to Bear Island. Samples were analyzed with pyrolysis-gas chromatography-mass spectrometry, generating a mass-based data set for MP in the marine atmosphere. Here we show the ubiquity of MP, even in remote Arctic areas with concentrations up to 37.5 ng m
-3 . Cluster of polyethylene terephthalate (max. 1.5 ng m-3 ) were universally present. TWP (max. 35 ng m-3 ) and cluster of polystyrene, polypropylene, and polyurethane (max. 1.1 ng m-3 ) were also detected. Atmospheric transport and dispersion models, suggested the introduction of MP into the marine atmosphere equally from sea- and land-based emissions, transforming the ocean from a sink into a source for MP., (© 2023. The Author(s).)- Published
- 2023
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49. Revised historical Northern Hemisphere black carbon emissions based on inverse modeling of ice core records.
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Eckhardt S, Pisso I, Evangeliou N, Zwaaftink CG, Plach A, McConnell JR, Sigl M, Ruppel M, Zdanowicz C, Lim S, Chellman N, Opel T, Meyer H, Steffensen JP, Schwikowski M, and Stohl A
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- Atmosphere, Soot analysis, Carbon, Fossil Fuels, Climate
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Black carbon emitted by incomplete combustion of fossil fuels and biomass has a net warming effect in the atmosphere and reduces the albedo when deposited on ice and snow; accurate knowledge of past emissions is essential to quantify and model associated global climate forcing. Although bottom-up inventories provide historical Black Carbon emission estimates that are widely used in Earth System Models, they are poorly constrained by observations prior to the late 20th century. Here we use an objective inversion technique based on detailed atmospheric transport and deposition modeling to reconstruct 1850 to 2000 emissions from thirteen Northern Hemisphere ice-core records. We find substantial discrepancies between reconstructed Black Carbon emissions and existing bottom-up inventories which do not fully capture the complex spatial-temporal emission patterns. Our findings imply changes to existing historical Black Carbon radiative forcing estimates are necessary, with potential implications for observation-constrained climate sensitivity., (© 2023. The Author(s).)
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- 2023
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50. Sources and fate of atmospheric microplastics revealed from inverse and dispersion modelling: From global emissions to deposition.
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Evangeliou N, Tichý O, Eckhardt S, Zwaaftink CG, and Brahney J
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- Dust, Environmental Monitoring, Oceans and Seas, Microplastics, Plastics
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We combine observations from Western USA and inverse modelling to constrain global atmospheric emissions of microplastics (MPs) and microfibers (MFs). The latter are used further to model their global atmospheric dynamics. Global annual MP emissions were calculated as 9.6 ± 3.6 Tg and MF emissions as 6.5 ± 2.9 Tg. Global average monthly MP concentrations were 47 ng m
-3 and 33 ng m-3 for MFs, at maximum. The largest deposition of agricultural MPs occurred close to the world's largest agricultural regions. Road MPs mostly deposited in the East Coast of USA, Central Europe, and Southeastern Asia; MPs resuspended with mineral dust near Sahara and Middle East. Only 1.8% of the emitted mass of oceanic MPs was transferred to land, and 1.4% of land MPs to ocean; the rest were deposited in the same environment. Previous studies reported that 0.74-1.9 Tg y-1 of land-based atmospheric MPs/MFs (< 5 mm) are transported to the ocean, while riverine transport is between 3.3 and 14 Tg y-1 . We calculate that 0.418 ± 0.201 Tg y-1 MPs/MFs (size up to 250 and 2500 µm) were transported from the land to ocean (large particles were ignored). Model validation against observations showed that particle removal must be urgently updated in global models., (Copyright © 2022 The Authors. Published by Elsevier B.V. All rights reserved.)- Published
- 2022
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