Surface Temperature from ERS-1 ATSR Infrared Thermal Satellite Data in Polar Regions

Abstract

The relationship between Along Track Scanning Radiometer (ATSR) thermal radiances and snow surface temperature for the Greenland ice sheet is examined through forward calculations of the LOWTRAN 7 radiative transfer model. Inputs to the model include in situ radiosonde profile measurements of temperature, pressure and humidity, surface temperatures, and cloud observations for spring-summer 1990 and 1991 from the ETH-CU research camp, located at 69°34?N, 49°18?W on the Greenland ice sheet. Atmospheric correction coefficients were determined through a statistical analysis of daily clear-sky profiles for three different combinations of the ATSR thermal infrared (TIR) channels. Using all available ATSR TIR information, the 11- and 12-?m channels in both the nadir and forward views showed the smallest rms error of less than 0.2 K in the estimated surface temperature. This dual-view algorithm was found to be least sensitive to changes in concentrations of atmospheric constituents, in contrast to the standard ?split-window? technique. Assuming accurate surface emissivities can be obtained, the dual-view algorithm is recommended for applications in polar regions where the variety of atmospheric conditions can be large.