An AeroCom assessment of black carbon in Arctic snow and sea ice
International audience Though many global aerosols models prognose surface deposition, only a few models have been used to directly simulate the radiative effect from black carbon (BC) deposition to snow and sea ice. Here, we apply aerosol de-position fields from 25 models contributing to two phases...
Published in: | Atmospheric Chemistry and Physics |
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Main Authors: | , , , , , , , , , , , , , , , , , , , , , , , , , , , , |
Other Authors: | , , , , , , , , , , , |
Format: | Article in Journal/Newspaper |
Language: | English |
Published: |
HAL CCSD
2014
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Subjects: | |
Online Access: | https://hal.archives-ouvertes.fr/hal-02872355 https://hal.archives-ouvertes.fr/hal-02872355/document https://hal.archives-ouvertes.fr/hal-02872355/file/Jiao2014_ACP.pdf https://doi.org/10.5194/acp-14-2399-2014 |
Summary: | International audience Though many global aerosols models prognose surface deposition, only a few models have been used to directly simulate the radiative effect from black carbon (BC) deposition to snow and sea ice. Here, we apply aerosol de-position fields from 25 models contributing to two phases of the Aerosol Comparisons between Observations and Models (AeroCom) project to simulate and evaluate within-snow BC concentrations and radiative effect in the Arctic. We accomplish this by driving the offline land and sea ice components of the Community Earth System Model with different deposition fields and meteorological conditions from 2004 to 2009, during which an extensive field campaign of BC measurements in Arctic snow occurred. We find that models generally underestimate BC concentrations in snow in northern Russia and Norway, while overestimating BC amounts elsewhere in the Arctic. Although simulated BC distributions in snow are poorly correlated with measurements , mean values are reasonable. The multi-model mean (range) bias in BC concentrations, sampled over the same grid cells, snow depths, and months of measurements, are −4.4 (−13.2 to +10.7) ng g −1 for an earlier phase of Aero-Com models (phase I), and +4.1 (−13.0 to +21.4) ng g −1 Published by Copernicus Publications on behalf of the European Geosciences Union. 2400 C. Jiao et al.: Black carbon in Arctic snow assessment for a more recent phase of AeroCom models (phase II), compared to the observational mean of 19.2 ng g −1. Factors determining model BC concentrations in Arctic snow include Arctic BC emissions, transport of extra-Arctic aerosols, precipitation , deposition efficiency of aerosols within the Arc-tic, and meltwater removal of particles in snow. Sensitivity studies show that the model-measurement evaluation is only weakly affected by meltwater scavenging efficiency because most measurements were conducted in non-melting snow. The Arctic (60-90 • N) atmospheric residence time for BC in phase II models ranges from 3.7 to 23.2 days, ... |
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