Extended Abstract (1.3M)P8.10
Seasonal Surface Spectral Emissivity Derived from Terra MODIS Data
Yan Chen, SAIC, Hampton, VA; and S. Sun-Mack, P. Minnis, D. F. Young, and W. L. Smith
Surface emissivity is essential for many remote sensing applications. It is also critical for deriving the surface skin temperature from satellite-based infrared measurements, determining thresholds for cloud detection and for estimating the emission of longwave radiation from the surface, an important component of the energy budget of the surface-abmosphere interface. In this paper, simultaneous data from Terra MODIS (Moderate-resolution Imaging Spectroradiometer) taken at 3.7, 8.4, 10.8,12.0 um are used to simultaneously derive the skin temperature and the surface emissivities at the same wavelengths. The methodology uses separate measurements of the clear sky temperatures in each channel determined by the CERES (Clouds and the Earth's Radiant Energy System) scene classification during the daytime and at night. The relationships between the various channels at night are used duringduring the day when solar reflectance affects the 3.7 um data. A set of simultaneous equations are then solved to derive the emissivities. Global results are derived from Terra MODIS while GOES-8 (Geostationary Operational Environmental Satellite) data are analyzed to examine the diurnal variation of this parameter over a mesoscale domain centered on the Atmospheric Radiation Measurements (ARM) Program Central facility in Northern Oklahoma, USA. Numerical weather analyses are used to provide soundings for correcting the observed radiances for atmospheric absorption. A theoretical sensitivity analysis is used to assess the potential errors in the results.
Poster Session 8, Retrievals and Cloud Products: Part 2
Thursday, 23 September 2004, 2:30 PM-4:30 PM
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