Comparison of temperature, pressure and specific humidity derived from Sentinel-6 with ERA5 and radiosonde

Abstract

The temperature, pressure and specific humidity data of Sentinel-6 (S6) products are compared with the ECMWF Reanalysis v5 (ERA5) and radio sounding in 2022. The overall STD of temperature, pressure and specific humidity for S6-ERA5 and S6-Radiosonde are 0.74 ℃, 0.45 hPa, 0.3 g/kg, 1.33 ℃, 0.51 hPa, 0.34 g/kg respectively. The study found that the consistency of these three atmospheric parameters between S6 and ERA5 is better than that between S6 and radiosonde. In the aspect of temporal characteristics, the specific humidity STD of S6-ERA5 decrease successively in summer, autumn, spring and winter. In the aspect of spatial characteristics, S6 has better retrieval ability of temperature values in the troposphere, but the maximum negative bias value of temperature between S6 and ERA5 is −1.57 ℃ at 41.7 km. The pressure bias values of S6 and ERA5 fluctuate greatly below the troposphere. In addition, the STD values of S6-ERA5 and S6-Radiosonde specific humidity data both show the decreasing characteristics in sequence from low to high latitudes.