MISR abstract

Diner, D.J., Fromm, M.D., Torres, O., Logan, J.A., Martonchik, J.V., Kahn, R.A., Moroney, C.M., Mazzoni, D.M., and Averill, C., (2004). New Satellite Observations of Upper Tropospheric/Lower Stratospheric Aerosols: Case Studies over the U.S. and Canada. Eos Trans. AGU, 85(47), Fall Meet. Suppl. 2004, Abstract # A21B-0744

During the past few years, a near-UV aerosol index derived from Total Ozone Mapping Spectrometer (TOMS) data has been used to detect aerosol plumes carried to high altitudes by intense convective activity. Using data from the Terra Multi-angle Imaging SpectroRadiometer (MISR), we can directly measure the heights of certain of these upper tropospheric/lower stratospheric (UTLS) plumes. Stereoscopic height retrievals are performed routinely and globally as part of the MISR data product generation system, using imagery from the instrument's nadir and near-nadir cameras to minimize the computer processing load. On a case-by-case basis, the stereo capability can be enhanced by using very oblique views, thereby increasing aerosol visibility and improving stereo height resolution and plume spatial coverage. In addition, MISR aerosol retrievals provide information on column-integrated particle abundances and microphysical properties such as size distribution and shape. We present case studies of TOMS-MISR observations of UTLS plumes, including an extensive smoke layer originating from the Chisholm fire in Alberta in May 2001, and an aerosol layer identified in TOMS data over the midwestern U.S. in August 2002, and subsequently explored using MISR data. The global prevalence of high-altitude (i.e., above 5 km) smoke- or dust-laden aerosols is unknown. A systematic investigation combining these satellite data sets would lead to new insights regarding plume origins, atmospheric residence times, climatic and environmental significance, and long-range particulate transport.

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