DETERMINATION OF ATMOSPHERIC OPTICAL-PROPERTIES DURING THE 1ST INTERNATIONAL SATELLITE LAND SURFACE CLIMATOLOGY PROJECT FIELD EXPERIMENT

Measurements of solar radiation were acquired with a multiwavelength, airborne, tracking sunphotometer during the First International Satellite Land Surface Climatology Project Field Experiment (FIFE). These measurements will permit the atmospheric correction of remotely sensed data acquired over the FIFE study area in eastern Kansas. Atmospheric optical properties derived from the sunphotometer measurements included total optical depth, aerosol optical depth, aerosol size distribution, aerosol phase function, and aerosol single scattering albedo. Data analyzed from two dates, June 6 and October 11, 1987, indicated the presence of aerosols with markedly different optical properties. Aerosol optical depths for the June 6 measurements exhibited a spectral dependence that peaked at the short wavelengths; whereas optical depths on October 11 decreased monotonically with wavelength and closely followed an Angstrom law wavelength dependence. Subsequent inversion of these data yielded a unimodal aerosol size distribution for June 6 and a power law size distribution (consistent with the Angstrom law wavelength dependence) for October 11. These differences are reflected in plots of the aerosol phase function. Variability of the atmospheric optical properties in both time and space illustrates the need to make sunphotometer measurements at the same time that remotely sensed data are acquired. © 1989 by the American Institute of Aeronautics and Astronautics, Inc.