HR: 0800h
AN: A41B-0448    [Abstracts]
TI: Detection and Retrieval of Mineral Dust Aerosols Using AERI Data
AU: * Hansell, R A
EM: rhansell@atmos.ucla.edu
AF: UCLA Department of Atmospheric & Oceanic Sciences, 405 Hilgard Ave, Room 7127 Math Sciences Bldg, Los Angeles, CA 90095, United States
AU: Ou, S
EM: ssou@atmos.ucla.edu
AF: UCLA Department of Atmospheric & Oceanic Sciences, 405 Hilgard Ave, Room 7127 Math Sciences Bldg, Los Angeles, CA 90095, United States
AU: Liou, K
EM: knliou@atmos.ucla.edu
AF: UCLA Department of Atmospheric & Oceanic Sciences, 405 Hilgard Ave, Room 7127 Math Sciences Bldg, Los Angeles, CA 90095, United States
AU: Tsay, S
EM: tsay@climate.gsfc.nasa.gov
AF: Goddard Space Flight Center NASA, Code 613.2, Greenbelt, MD 20771, United States
AU: Ji, Q
EM: ji@climate.gsfc.nasa.gov
AF: University of Maryland, College Park, 2207 Computer and Space Sciences Building (#224), College Park, MD 20742, United States
AU: Reid, J
EM: jeffrey.reid@nrlmry.navy.mil
AF: Naval Research Laboratory, 7 Grace Hopper Ave., Stop 2, Monterey, CA 93943, United States
AB: A dust detection/retrieval method using ground-based Atmospheric Emitted Radiance Interferometer (AERI) brightness temperature spectra has been developed. Taking advantage of the high spectral resolution of AERI, we exploit differences between the spectral absorptive power for dust and cloud in prescribed thermal IR window sub-bands to separate dust from clouds, and to retrieve dust IR optical depths. Dust composition was prescribed using the refractive index datasets for minerals commonly observed around the United Arab Emirates (UAE) region including quartz, kaolinite, kaolinite mixed with hematite and calcium carbonate and for comparison with the individual minerals, the refractive indices of the Volz Saharan dust model were also examined. Five dust microphysical models were constructed using in-situ data from the UAE Unified Aerosol Experiment (UAE²). The single-scattering properties for oblate spheroids and hexagonal plates, two particle geometries routinely interpreted in electron microscopy, were computed using the T-matrix and FDTD programs. Sensitivity of the AERI spectra to dust composition, shape, size, and precipitable water vapor was investigated using the CHARTS radiative transfer program. AERI data for four dust and cirrus cases from the UAE² field campaign were selected to demonstrate the effectiveness of the detection/retrieval approach. The AERI detection/retrieval results compare well with the values determined from coincident and collocated MPLNET micro pulse lidar and AERONET sun-photometer measurements respectively. The AERI retrieved optical depths (scaled from IR to visible) were found to be within 30% of those measured by AERONET. This novel AERI detection/retrieval approach will help detect and track regional dust events, and quantify dust IR radiative forcing parameters for both daytime and nighttime conditions.
DE: 3311 Clouds and aerosols
DE: 3359 Radiative processes
DE: 3360 Remote sensing
DE: 3394 Instruments and techniques
DE: 3399 General or miscellaneous
SC: Atmospheric Sciences [A]
MN: 2007 Fall Meeting