Knowledge of the temperature profile of the atmosphere is of critical importance in climatological and meteorological studies. Data from AMSU-A (Advanced Microwave Sounding Unit-A) radiometer on the new generation polar orbiting satellites of National Oceanic and Atmospheric Administration (NOAA) are well suited for the continuous retrieval of temperature profiles in polar regions. Since in these regions, the surface is highly variable (open water,various ice types), it is essential to approximately know the emissivity for all possible scan angles and window channels of AMSU-A in order to estimate the surface contribution to the brightness temperature measured by the satellite. Here we present an algorithm to calculate the surface emissivities from AMSU-A data and ECMWF data and present results for different test regions and for different months. The angular and spectral dependence of the emissivity is studied. The emissivity sensitivity to errors in the input parameters are examined.