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Title: Indirect and semi-direct aerosol campaign: The impact of Arctic aerosols on clouds

A comprehensive dataset of microphysical and radiative properties of aerosols and clouds in the boundary layer in the vicinity of Barrow, Alaska, was collected in April 2008 during the Indirect and Semi-Direct Aerosol Campaign (ISDAC). ISDAC's primary aim was to examine the effects of aerosols, including those generated by Asian wildfires, on clouds that contain both liquid and ice. ISDAC utilized the Atmospheric Radiation Measurement Pro- gram's permanent observational facilities at Barrow and specially deployed instruments measuring aerosol, ice fog, precipitation, and radiation. The National Research Council of Canada Convair-580 flew 27 sorties and collected data using an unprecedented 41 stateof- the-art cloud and aerosol instruments for more than 100 h on 12 different days. Aerosol compositions, including fresh and processed sea salt, biomassburning particles, organics, and sulfates mixed with organics, varied between flights. Observations in a dense arctic haze on 19 April and above, within, and below the single-layer stratocumulus on 8 and 26 April are enabling a process-oriented understanding of how aerosols affect arctic clouds. Inhomogeneities in reflectivity, a close coupling of upward and downward Doppler motion, and a nearly constant ice profile in the single-layer stratocumulus suggests that vertical mixing is responsible for its longevity observed duringmore » ISDAC. Data acquired in cirrus on flights between Barrow and Fairbanks, Alaska, are improving the understanding of the performance of cloud probes in ice. Furthermore, ISDAC data will improve the representation of cloud and aerosol processes in models covering a variety of spatial and temporal scales, and determine the extent to which surface measurements can provide retrievals of aerosols, clouds, precipitation, and radiative heating.« less
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  1. Univ. of Illinois at Urbana-Champaign, Urbana, IL (United States)
  2. Pacific Northwest National Lab. (PNNL), Richland, WA (United States)
  3. The Pennsylvania State Univ., University Park, PA (United States)
  4. Environment Canada, Downsview, ON (Canada)
  5. National Research Council of Canada, Ottawa, ON (Canada)
  6. Los Alamos National Lab. (LANL), Los Alamos, NM (United States)
  7. Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)
  8. Stratton Park Engineering Company, Boulder, CO (United States)
  9. Scripps Institution of Oceanography, La Jolla, CA (United States)
  10. National Center for Atmospheric Research, Boulder, CO (United States)
  11. Climate Diagnostic Center, and NOAA/ESRL, Boulder, CO (United States)
  12. Univ. of Wisconsin-Madison, Madison, WI (United States)
  13. Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)
  14. Texas A & M Univ., College Station, TX (United States)
Publication Date:
Report Number(s):
Journal ID: ISSN 0003-0007
Grant/Contract Number:
Accepted Manuscript
Journal Name:
Bulletin of the American Meteorological Society
Additional Journal Information:
Journal Volume: 92; Journal Issue: 2; Journal ID: ISSN 0003-0007
American Meteorological Society
Research Org:
Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)
Sponsoring Org:
Country of Publication:
United States
OSTI Identifier: