The Effects of Long-Range Transport of Agricultural Smoke on AOD in Houston, TX: Insights from NASA SEAC4RS and DISCOVER-AQ

Friday, 19 December 2014
Andreas Joel Beyersdorf1, Luke D Ziemba1, Bruce E Anderson1, Gao Chen2, Chelsea Corr3, Suzanne Crumeyrolle4, Richard Moore1, Kenneth Lee Thornhill II5 and Edward Winstead5, (1)NASA Langley Research Center, Hampton, VA, United States, (2)NASA Langley Research Ctr, Hampton, VA, United States, (3)Oak Ridge Associated Universities Inc., Oak Ridge, TN, United States, (4)Laboratoire d'Optique Atmosphérique (Lille), Villeneuve, France, (5)Science Systems and Applications, Inc. Hampton, Hampton, VA, United States
In September 2013, the NASA P-3B performed systematic in-situ profiles throughout the Houston, TX area as part of the DISCOVER-AQ project. During this campaign, smoke originating from agricultural fires in the Mississippi River Valley contributed up to 80% of the aerosol optical depths (AODs) and thus complicated estimation of ground-level PM2.5 from AOD. Comparison with measurements of fresh agricultural fires during both DISCOVER-AQ and SEAC4RS showed that these lofted layers were considerably aged with higher single scattering albedos and water-uptake potential (f(RH)). This more hygroscopic aged smoke (with f(RH)’s of 1.5) created higher AODs than would be obtained if fresh smoke (f(RH) on the order of 1.1) had been present. In addition, profiling done as part of SEAC4RS throughout the Southeast will be compared to ground-based PM2.5 allowing for determination of background aerosol vertical distributions in the region and the extent of the smoke transport. Historic long-term measurements of AOD (from AERONET) and PM2.5 (from ground-based monitoring sites) will also be addressed to determine the frequency of these long-range transport events.