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Title: Seasonality of global and Arctic black carbon processes in the Arctic Monitoring and Assessment Programme models: Global and Arctic Black Carbon Processes

This study quantifies black carbon (BC) processes in three global climate models and one chemistry transport model, with focus on the seasonality of BC transport, emissions, wet and dry deposition in the Arctic. In the models, transport of BC to the Arctic from lower latitudes is the major BC source for this region while Arctic emissions are very small. All models simulated a similar annual cycle of BC transport from lower latitudes to the Arctic, with maximum transport occurring in July. Substantial differences were found in simulated BC burdens and vertical distributions, with CanAM (NorESM) producing the strongest (weakest) seasonal cycle. CanAM also has the shortest annual mean residence time for BC in the Arctic followed by SMHI-MATCH, CESM and NorESM. The relative contribution of wet and dry deposition rates in removing BC varies seasonally and is one of the major factors causing seasonal variations in BC burdens in the Arctic. Overall, considerable differences in wet deposition efficiencies in the models exist and are a leading cause of differences in simulated BC burdens. Results from model sensitivity experiments indicate that scavenging of BC in convective clouds acts to substantially increase the overall efficiency of BC wet deposition in the Arctic,more » which leads to low BC burdens and a more pronounced seasonal cycle compared to simulations without convective BC scavenging. In contrast, the simulated seasonality of BC concentrations in the upper troposphere is only weakly influenced by wet deposition in stratiform (layer) clouds whereas lower tropospheric concentrations are highly sensitive.« less
Authors:
 [1] ;  [2] ;  [3] ;  [4] ;  [5] ;  [6] ;  [7]
  1. School of Earth and Ocean Sciences, University of Victoria, Victoria British Columbia Canada; Department of Meteorology, COMSATS Institute of Information Technology, Islamabad Pakistan
  2. School of Earth and Ocean Sciences, University of Victoria, Victoria British Columbia Canada; Canadian Center for Climate Modelling and Analysis, Environment and Climate Change Canada, University of Victoria, Victoria British Columbia Canada
  3. Department of Atmospheric, Oceanic and Space Sciences, University of Michigan, Ann Arbor Michigan USA
  4. Center for International Climate and Environmental Research-Oslo, Oslo Norway
  5. Swedish Meteorological and Hydrological Institute, Norrköping Sweden
  6. Atmospheric Sciences and Global Change Division, Pacific Northwest National Laboratory, Richland Washington USA
  7. Climate Chemistry Measurements and Research, Environment and Climate Change Canada, Toronto Ontario Canada
Publication Date:
OSTI Identifier:
1324902
Report Number(s):
PNNL-SA-110584
Journal ID: ISSN 2169-897X; KP1703010
DOE Contract Number:
AC05-76RL01830
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Geophysical Research: Atmospheres; Journal Volume: 121; Journal Issue: 12
Publisher:
American Geophysical Union
Research Org:
Pacific Northwest National Laboratory (PNNL), Richland, WA (US)
Sponsoring Org:
USDOE
Country of Publication:
United States
Language:
English