Purpose. The purpose of the work is to study the potential for improving the spatial resolution of the Advanced Microwave Scanning Radiometer 2 (AMSR2) on C-band channels using the measurements at 36.5 GHz frequency to analyze the underlying surface parameters of the Arctic seas.

Methods and Results. The results of numerical modeling of the brightness temperature (Тb) of microwave radiation from the sea ice-ocean-atmosphere system under conditions of the non-scattering Arctic atmosphere, as well as the calculations of Тb for the atmospheric and oceanic parameters based on the ERA5 reanalysis data were used. The values of sea ice effective emission coefficients previously calculated for the entire Arctic region were applied in calculations. The Тb sensitivity to atmospheric radiation, surface temperature and underlying surface emission coefficients at the 6.9 and 36.5 GHz measurement channels at the horizontal and vertical polarizations, and also variability of the above parameters in the Arctic were assessed. Depending on the surface type and based on the modeling results, proposed are the formulas for calculating the Тb fields at the 6.9 GHz frequency at the enhanced spatial resolution, in which Тb at the 6.9 GHz frequency of the original resolution and Тb at the 36.5 GHz frequency of the Level 1R satellite product were used.

Conclusions. The developed approach expands the possibilities of using the AMSR2 data for a detailed study of the parameters of Arctic seas partially or completely covered with first-year ice of various types and concentration. For the areas of continuous multi-year consolidate ice, application of the described method to improving the spatial resolution of measurements at 6.9 GHz, especially in vertical polarization, seems impossible. The errors and applicability of the above approach are conditioned by the variability of atmospheric water content parameters in a low spatial resolution pixel of measurements at the 6.9 GHz frequency.