Aerosol Properties Over the United Arab Emirates and Arabian Gulf from MISR Multi-angle Satellite Imaging

The MISR instrument aboard NASA's Terra satellite participated in the UAE-2 campaign, August-October 2004. This campaign represented a unique opportunity to study the complex aerosol situation in the Arabian Gulf region, in the context of a first-rate collection of aircraft and surface-based instruments, giving us the opportunity to do some groundbreaking satellite aerosol validation work. We aimed (1) to validate MISR aerosol retrieval results for dust and pollution particles over dark and light surfaces, and (2) to contribute regional maps of aerosol optical thickness (AOT) and particle micro-physical properties, giving spatial context to the field-instrument measurements, and moving toward a satellite-based regional aerosol climatology. The validation effort benefited from the combination of an instrumented aircraft and a regional network of surface-based sun photometers. We obtained high-quality sub-orbital data coincident with MISR overpasses on three days: September 01, 10, and 12, representing a range of dusty and polluted conditions over the Arabian Gulf, and primarily dusty air over the bright desert south of the UAE coast. With these data, we are quantifying MISR sensitivity to column AOT, dust size and shape, pollution particle size and single-scattering albedo (SSA), and dust-pollution mixtures. Using the MISR Research Aerosol Retrieval, preliminary results indicate an ability to distinguish three-to-five size bins from space, and to separate spherical from non-spherical particles over water. In this talk, we plan to present preliminary over-land results as well. Regional maps of AOT, angstrom exponent, and SSA, from the latest version of the MISR Standard Aerosol retrieval will be presented. Once the full set of field measurement analyses is reported and tested against MISR Research Retrieval runs, the results will help us fine-tune the MISR Standard Retrieval, which will then produce refined MISR aerosol products for the entire global, five-plus-year MISR mission, including the UAE-2 events themselves. The MISR work is performed at the Jet Propulsion Laboratory, California Institute of Technology, under contract with the National Aeronautics and Space Administration.

http://uae2.gsfc.nasa.gov/