HR: 14:50h
AN: A13F-05    [Abstracts]
TI: Patterns and connections between aerosols, clouds and vegetation in the Amazon as seen by the twin MODIS sensors aboard Terra and Aqua
AU: * Meskhidze, N
EM: nmeskhidze@ncsu.edu
AF: Marine Earth and Atmospheric Sciences, North Carolina State University, 5134 Jordan Hall, Raleigh, NC 27613, United States
AU: Negrón Juárez, R
EM: rjuarez@tulane.edu
AF: Ecology and Evolutionary Biology, Tulane University, 6823 St. Charles Ave., New Orleans, LA 70118, United States
AU: Remer, L
EM: Lorraine.A.Remer@nasa.gov
AF: NASA Goddard Space Flight Center, code 613.2 Laboratory for Atmospheres, Greenbelt, MD 20771, United States
AU: Platnick, S
EM: steven.platnick@nasa.gov
AF: NASA Goddard Space Flight Center, code 613.2 Laboratory for Atmospheres, Greenbelt, MD 20771, United States
AU: Aiyyer, A
EM: aaiyyer@ncsu.edu
AF: Marine Earth and Atmospheric Sciences, North Carolina State University, 5134 Jordan Hall, Raleigh, NC 27613, United States
AB: In this study, twin Moderate Resolution Imaging Spectroradiometer (MODIS) sensors aboard NASA's Terra and Aqua satellites are used for characterization of cloud development and identification of processes affecting cloud formation. We find that much of the development of microphysical properties of water clouds over the Brazilian Legal Amazon can be characterized by the simple difference between those properties observed at the two times of MODIS overpass, only 3 hours apart. The time window is small enough that observed differences in cloud properties are primarily associated with the local events; therefore, it is ideal for exploring the effects of plant transpiration, biomass burning and Secondary Organic Aerosol (SOA) formation on regional cloud properties. In this region we find that the effective cloud droplet radius observed in the afternoon by Aqua-MODIS is systematically higher than the effective radii observed in the morning by Terra-MODIS. The difference corresponds to the invigoration of convection in the afternoon with the corresponding growth of droplet size. The monthly mean difference is 1 to 2 um, depending on season, but the overall pattern of the difference prevails throughout the Amazon, is repeated over other tropical rain forest regions globally, and is strikingly different from other types of cloud systems around the globe. Furthermore, we find that the effective radius difference found in the Amazon is inversely correlated to measures of evapotranspiration and all-sky solar radiation at the surface, but is not well-correlated to precipitation. The picture that emerges is a complex one that intertwines a light- limited forest, aerosols (both biogenic and anthropogenic) and cloud development.
DE: 0305 Aerosols and particles (0345, 4801, 4906)
DE: 0315 Biosphere/atmosphere interactions (0426, 1610)
DE: 3305 Climate change and variability (1616, 1635, 3309, 4215, 4513)
DE: 3311 Clouds and aerosols
DE: 3359 Radiative processes
SC: Atmospheric Sciences [A]
MN: 2007 Fall Meeting