HR: 1340h
AN: A33A-0853    [Abstracts]
TI: Comparison of Aerosol Radiative Forcing Over Arabian Gulf and Tropical Indian Ocean : A Multi-Sensor Study AU: * Patadia, F
EM: falguni@nsstc.uah.edu
AF: Department of Atmospheric Sciences,University of Alabama in Huntsville, 320 Sparkman Drive, NSSTC, Huntsville, AL 35806 United States
AU: Christopher, S A
EM: sundar@nsstc.uah.edu
AF: Department of Atmospheric Sciences,University of Alabama in Huntsville, 320 Sparkman Drive, NSSTC, Huntsville, AL 35806 United States
AU: Reid, J
EM: reidj@nrlmry.navy.mil
AF: Aerosol and Radiation Modeling Section, Marine Meteorology Division,NRL, 7 Grace Hopper Ave., Stop 2, Monterey, CA 93943-5502 United States
AU: Babu, S S
EM: sureshspl@yahoo.co.in
AF: Space Physics Laboratory, Vikram Sarabhai Space Centre, VSSC, Thiruvanantpuram, 695022 India
AU: Satheesh, S K
EM: satheesh@caos.iisc.ernet.in
AF: Centre for Atmospheric and Oceanic Sciences, Indian Institute of Sciences, IISc, Bangalore, 560012 India
AU: Moorthy, K K
EM: k-k-moorthy@eth.net
AF: Centre for Atmospheric and Oceanic Sciences, Indian Institute of Sciences, IISc, Bangalore, 560012 India
AB: Large variations in aerosol radiative forcing can have a significant impact on regional climate changes. Depending on the underlying surface albedo, the aerosol type, amount, shape, size and vertical distribution, the aerosol radiative forcing both at the top of the atmosphere (TOA) and the surface can either be negative or positive. This uncertainty in the sign of aerosol radiative forcing coupled with the uncertainty in its magnitude leads to large uncertainties in determining the climate change due to the aerosol-radiation interactions. An effort to understand how aerosol particles over bright surfaces impact the regional radiation budget and hence the climate was made by the dedicated UAE2 (United Arab Emirates Unified Aerosol Experiment) field experiment conducted over the Arabian Gulf region. Recent data shows that this region is one of the largest confluences of aerosol types in the world. The exceedingly complex meteorology, large amount of emissions, natural dust episodes and transport of smoke from the Indian subcontinent makes it a unique laboratory. The Indian Ocean basin provides a yet another unique laboratory to study aerosols over dark background. In the present study the aerosol radiative forcing over the Arabian Gulf region for the UAE2 time period (August 8 - October 2, 2004) and over the Indian Ocean basin (Bay of Bengal and Arabian Sea) for the entire year of 2003 has been compared in order to understand the aerosol forcing over different backgrounds and its climatic implications. The suite of ground based observations over UAE2 region coupled with observations from CERES (Clouds and Earth's Radiant Energy System), MODIS (Moderate Resolution Imaging Spectroradiometer) and MISR(Multi-angle Imaging Spectroradiometer) satellite sensors over the two study regions, provides unique insights to our basic understanding of the aerosol-radiation interaction. Comparison of satellite based aerosol optical thickness (AOT) observations against extensive collocated measurements made over the Indian Ocean during several ship cruises in 2003 and ground based observations over Arabian Gulf will be presented. Seasonal variation of AOT and radiative forcing both at the TOA and at the surface will be discussed. The transport of aerosols to and from the Indian subcontinent will be investigated. This study is unique in that it uses a combination of a large number of ground and collocated multi-sensor observations to derive the required information.
DE: 0305 Aerosols and particles (0345, 4801, 4906)
DE: 0321 Cloud/radiation interaction
DE: 0360 Radiation: transmission and scattering
DE: 0480 Remote sensing
DE: 4906 Aerosols (0305, 4801)
SC: Atmospheric Sciences [A]
MN: Fall Meeting 2005