High-latitude surface temperature estimates from thermal satellite data

The surface temperature of the polar regions controls sea ice growth, snow melt, and surface-atmosphere energy exchange. However, our limited knowledge of polar surfaces and atmospheres has hampered the development of methods to estimate surface temperature with satellite data. In this article, clear-sky surface-temperature retrieval algorithms for use with the Advanced Very High Resolution Radiometer (AVHRR) and the Along Track Scanning Radiometer (ATSR) for the Arctic and the Antarctic, over ocean and land, are presented. The methods are similar to those used in estimating sea and land surface temperatures but are developed with data specific to the polar regions. An extensive validation analysis using an annual cycle of surface measurements gives accuracies in the range of 0.3-2.1 K, the larger errors being attributable to the spatially variable surface of the validation area. For homogeneous surfaces the expected accuracy is sufficient for many climate process studies. (C) Elsevier Science Inc., 1997.