Analysis of the MTVZA-GYa Microwave Imager/Sounder Measurements over the Arctic Sea Ice and Sea Water

Variability of the sea ice vertically and horizontally polarized microwave radiation at four frequencies in winter 2020 is studied on the basis of the Russian satellite passive microwave instrument MTVZA-GYa measurements from the Meteor-M N2-2 satellite. Physical modeling of the microwave radiation transfer in the sea-ice-atmosphere system under non-scattering conditions is used to derive the brightness temperatures (BT) of the sea ice microwave radiation at 10.6, 18.7, 23.8 and 36.5 GHz from the MTVZA-GYa measured brightness and profiles of the atmospheric meteorological parameters. Era5 re-analysis data on the profiles of the atmospheric meteorological parameters are explored in the calculations. The sea ice areas are selected on the basis of the sea ice maps of the Arctic and Antarctic Research Institute (AARI) and sea ice concentration data, derived from the AMSR2 measurements. Era5 data on the sea ice temperature (SIT) are used to downscale the sea ice BTs to the sea ice emissivities at the four MTVZA-GYa frequencies on vertical and horizontal polarization. The time evolution of the sea ice emissivity values is studied for the predefined sea ice types, defined with the AARI sea ice maps.