HR: 0800h
AN: A51B-02    [Abstracts]
TI: Characterization of Fine and Coarse Modes of Atmospheric Aerosols Using MFRSR Measurements
AU: * Alexandrov, M D
EM: malexandrov@giss.nasa.gov
AF: Columbia University, 2880 Broadway, New York, NY 10025, United States
AU: * Alexandrov, M D
EM: malexandrov@giss.nasa.gov
AF: NASA Goddard Institute for Space Studies, 2880 Broadway, New York, NY 10025, United States
AU: Lacis, A A
EM: alacis@giss.nasa.gov
AF: NASA Goddard Institute for Space Studies, 2880 Broadway, New York, NY 10025, United States
AU: Carlson, B E
EM: bcarlson@giss.nasa.gov
AF: NASA Goddard Institute for Space Studies, 2880 Broadway, New York, NY 10025, United States
AU: Cairns, B
EM: bcairns@giss.nasa.gov
AF: Columbia University, 2880 Broadway, New York, NY 10025, United States
AU: Cairns, B
EM: bcairns@giss.nasa.gov
AF: NASA Goddard Institute for Space Studies, 2880 Broadway, New York, NY 10025, United States
AB: Ground-based sun-photometry provides an important source of information for characterization of atmospheric aerosols, as well as a validation tool for global satellite aerosol retrievals. While Multi-Filter Rotating Shadow- band Radiometers (MFRSRs) are widely used for measurements of aerosol optical thickness (AOT), the information content of MFRSR data is substantially larger. Our recently updated MFRSR data analysis algorithm allows us also to partition the spectral AOT into fine and coarse modes and to retrieve the fine mode effective radius. Our sensitivity study demonstrated that for a typical accuracy 0.01 of AOT measurements the trade-offs between the spectral aerosol extinction in visible range and NO₂absorption effectively prevent conclusive estimation of NO₂column from MFRSR data, and may bias aerosol size retrievals. This prompted us to adopt a constrained retrieval technique which relies on climatological amounts of NO₂and uses ozone columns from TOMS satellite measurements. To demonstrate geographical and seasonal variability of aerosol properties we present the results of application of the described algorithm to a multi-year dataset from the local MFRSR network at the Southern Great Plains (SGP) site operated by the U.S. Department of Energy Atmospheric Radiation Measurement (ARM) Program. The network consists of 21 instruments located at SGP's Central and Extended Facilities and covers the area of approximately 3 by 4 degrees in northern Oklahoma and southern Kansas. We also present a detailed inter-comparison of our retrievals of total, fine, and coarse AOT, and fine mode effective radius with the correlative AERONET almucantar scan analysis results (Version 2) derived from a CIMEL sun-photometer co-located with two MFRSRs at the SGP's Central Facility.
DE: 0305 Aerosols and particles (0345, 4801, 4906)
DE: 0360 Radiation: transmission and scattering
DE: 0394 Instruments and techniques
DE: 0478 Pollution: urban, regional and global (0345, 4251)
DE: 0480 Remote sensing
SC: Atmospheric Sciences [A]
MN: 2007 Joint Assembly