Analysis of Sar Images Obtained in Hurricane Conditions for Estimates of Co2 Atmosphere-Ocean Flux

The research is devoted to the problem of estimations of CO2 fluxes between the hydrosphere and atmosphere. Hurricane-force winds lead to intensive wave breaking, with formation of spray in the air, and bubbles in the water. It strongly intensifies gas flux characterizing by power dependence of the transfer rate on the 10-m height wind speed used for approximation of the empirical results. But available data demonstrate wide variation which leads large confidence limits for coefficients in empirical approximations. On the other hand, there is an obvious problem of obtaining reliable data on the wind speed. Widely used reanalysis data typically underestimate wind speed magnitude, due to the low spatial and temporal resolution. One of the most promising ways to measure near water wind speed is the use of the data of remote sensing. The present study used technique to achieve wind speed based on the processing sea surface images obtained in cross-polarized mode with C-band (5.4 GHz) radar with synthesized aperture (RSA) of Radarsat-2 satellite. To this propose geophysical model function (GMF) which binds values of wind speed and normalized radar cross section in cross-polarized mode was used. This GMF was developed in a special laboratory experiment on the wind-wave flumes for a wide range of wind speeds, including hurricanes. In turn, for parameterization of gas transfer rate results of recent laboratory experiment on high speed wind-wave flume was used.