797 The Impact of Convection in the Tropical Atlantic Ocean on the Processing, Transport and Redistribution of Dust Aerosols

Wednesday, 13 January 2016
Kathryn Sauter, University of Wisconsin , Madison, WI; and T. L'Ecuyer

The distribution of mineral dust aerosols that originate from the Saharan Desert and sweep across the tropical Atlantic Ocean can significantly impact climate processes in the region. The Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observations (CALIPSO) mission was launched in April 2006 as a part of the A-Train constellation in order to gain a better understanding of the role that aerosols and clouds play in the complex climate system [Winker et al., 2006, 2007]. The ability to assess the vertical and spatial transportation of dust across the Atlantic Ocean using CALIPSO aerosol retrievals provides valuable insight into the effects of dust aerosols on the Earth's climate system. This study couples in-situ observations of dust storm events in 2006 with aerosol optical depth from the polar orbiting CALIPSO ground track and the GOES East Pathfinder Atmospheres Extended (PATMOS-x) geostationary cloud dataset to constrain the processing, transport and redistribution of dust aerosols over the tropical Atlantic Ocean before and after the passage of convection. Cloud top temperature, cloud optical thickness, and cloud top size are further used to quantify the sensitivity of wet deposition to the intensity of tropical convection. Identifying the removal impacts from convection on the dust aerosols will allow for the interpretation and understanding of processes that transport and redistribute the dust. Preliminary results provide evidence that convection both reduces downstream dust optical depths and occasionally transports dust to higher altitudes than the main Saharan dust layer. These redistribution and scavenging effects have implications for direct and indirect impacts of dust on radiation balance both locally and downstream of the convection. Further analysis of these complementary datasets may offer new revelations into aerosol-cloud climate interactions.
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