Impact of Elevated Aerosol Layers on Aerosol Optical Depth during TCAP
Authors
Larry Berg — Pacific Northwest National Laboratory
Jerome D Fast — Pacific Northwest National Laboratory
James Barnard — University of Nevada Reno
Sharon P Burton — NASA - Langley Research Center
Duli Chand — Pacific Northwest National Laboratory
Jennifer M. Comstock — Pacific Northwest National Laboratory
Richard A. Ferrare — NASA - Langley Research Center
John W. Hair — NASA - Langley Research Center
Chris A. Hostetler — NASA Langley Research Center
John Hubbe — Pacific Northwest National Laboratory
Celine Delphine Kluzek — Pacific Northwest National Laboratory
Fan Mei — Pacific Northwest National Laboratory
Joseph J. Michalsky — NOAA/Earth System Research Laboratory/Global Monitoring Division & CU-Boulder/Cooperative Institute for Research in Environmental Sciences
Raymond Rogers — NASA - Langley Research Center
Arthur J Sedlacek — Brookhaven National Laboratory
Beat Schmid — Pacific Northwest National Laboratory
John E Shilling — Pacific Northwest National Laboratory
Stephen R. Springston — Brookhaven National Laboratory
Jason Tomlinson — Pacific Northwest National Laboratory
Jacqueline Mary Wilson — Pacific Northwest National Laboratory
Alla Zelenyuk-Imre — Pacific Northwest National Laboratory
Carl M. Berkowitz — Pacific Northwest National Laboratory
Category
Absorbing Aerosol
Description
The Two Column Aerosol Project (TCAP) measured key aerosol and cloud parameters in two atmospheric columns, one located over Cape Cod, Massachusetts and another approximately 200 km from the coast over the Atlantic Ocean. As described in this work, aerosol measurements made during TCAP included size distribution, chemical composition, optical properties and vertical distribution. Cloud properties were measured using one of the research aircraft and a suite of cloud radars. TCAP data will be utilized for evaluating and improving regional and global models of the atmosphere. Several aspects make TCAP unique, including the year-long deployment of the US Department of Energy’s Atmospheric Radiation Measurement (ARM) Climate Research Facility (AMF) and two aircraft intensive operations periods supported by the ARM Airborne Facility, one conducted in July 2012 (Phase 1) and a second in February 2013 (Phase 2). Using data from the AMF and two research aircraft, we document the impact of elevated aerosol layers on the columnar aerosol optical depth (AOD) during Phase 1. The elevated layers were found on virtually all of the days sampled by the research aircraft and contributed as much as 80% of the total AOD, depending on the particular day. These layers had smaller single scattering albedos than aerosol layers near the surface and contained increased amounts of biomass burning aerosol. The impact of the elevated layers is notable for several reasons: it implies that the aerosol absorption is spread over a deeper layer of the atmosphere, it shows that in situ measurements at the surface may not be representative of the entire aerosol population in the atmospheric column, and highlights the importance of long-range transport.Lead PI
Larry Berg — Pacific Northwest National Laboratory