A223-0019
Where There’s Smoke, There’s Humidity: Exploring the Water Vapor Associated with the Free-Tropospheric Biomass Burning Plume over the Southeast Atlantic Ocean
Wednesday, 16 December 2020
Poster
Kristina Pistone1, Paquita Zuidema2, Rob Wood3, Michael S Diamond4, Pablo E Saide5, Arlindo daSilva6, Gonzalo Andres Ferrada7, James Robert Podolske8, David Noone9, Jens Redemann10, Leonhard Pfister11, Samuel E LeBlanc1, Connor Flynn12, Rei Ueyama8, Ju-Mee Ryoo13, Michal Segal-Rosenhaimer14,15, Meloe S Kacenelenbogen8 and Yohei Shinozuka16, (1)Bay Area Environmental Research Institute, Moffett Field, CA, United States, (2)University of Miami, Miami, FL, United States, (3)University of Washington Seattle Campus, Seattle, WA, United States, (4)University of Washington, Atmospheric Sciences, Seattle, WA, United States, (5)University of California Los Angeles, Atmospheric and Oceanic Sciences, Los Angeles, CA, United States, (6)NASA Goddard Space Flight Center, Greenbelt, MD, United States, (7)University of Iowa, Center for Global and Regional Environmental Research, Iowa City, IA, United States, (8)NASA Ames Research Center, Moffett Field, CA, United States, (9)University of Auckland, Department of Physics, Auckland, New Zealand, (10)University of Oklahoma, School of Meteorology, Norman, OK, United States, (11)NASA, Moffett Field, CA, United States, (12)University of Oklahoma Norman Campus, Norman, United States, (13)NASA Ames Research Center, Atmospheric Sciences Branch, Moffett Field, CA, United States, (14)Bay Area environmental Research Institute, NASA Ames Research Center, Moffett Field, CA, United States, (15)Geophysics Department, School of Earth and environmental Sciences, Tel-Aviv university, Tel-Aviv, Israel, (16)Universities Space Research Association Moffett Field, Moffett Field, CA, United States
Abstract:
In southern Africa, widespread springtime agricultural fires produce substantial biomass burning (BB) emissions over the region. These seasonal smoke plumes are advected westward over the persistent stratocumulus cloud deck in the Southeast Atlantic (SEA) Ocean, resulting in complex interactions between aerosols, clouds, and meteorology. Thus observations in this region offer an excellent opportunity to better understand these interactions. No less important is the question of how the local meteorology may either affect or be affected by the presence of the biomass burning plume, both over the emission region and over the SEA cloud deck.
We will discuss airborne observations of the SEA made in September 2016 during the first field deployment of the NASA ORACLES (ObseRvations of Aerosols above CLouds and their intEractionS) campaign. In observations collected from multiple independent instruments (three measures of water vapor, inlet-based carbon monoxide (CO), and sunphotometer-based column water vapor and aerosol optical depth) from near-surface up to 6-7km, we observe a strongly linear correlation between BB plume indicators and atmospheric water vapor content, seen at all altitudes above the boundary layer.
We then use reanalyses (ERA5 and MERRA-2) and specialized WRF-Chem model outputs to trace the plume-vapor relationship to an initial humid source over the continent, which develops the observed correlation during transport, likely due to mixing with low humidity/low CO air. Our analysis indicates that the initial higher plume water vapor content is independent of the biomass burning emissions. These results have implications for estimations of aerosol radiative effects over the region: the presence of climatological water vapor in the region, and the latent energy it carries, will have radiative and dynamical effects on the local atmosphere. Better understanding of the mechanisms which cause the water vapor to covary with plume strength is important to accurately quantify direct, semi-direct, and indirect aerosol effects in this region.
