Analyzing the Accuracy of ERA-Interim Data on Total Atmospheric Water Vapor in the Arctic Estimated from AMSR2 Data

The accuracy of the ERA-Interim reanalysis data on total atmospheric water vapor is assessed using the AMSR2 (Advanced Microwave Scanning Radiometer 2) measurements. The values of total column water vapor over the open ocean obtained by applying the improved algorithm to the ASMR2 data are used as reference ones to evaluate the quality of water vapor content reproduced by the reanalysis. The analysis performed for the Arctic region for 2015 and based on the average daily values demonstrated a high accuracy of ERA-Interim data on the Arctic water vapor equal to 1.1 kg/m2, which decreases for the water vapor values above 15 kg/m2. Under such conditions, the ERA-Interim data underestimate the water vapor content by several kg/m2. The accuracy of ERA-Interim total water vapor over the seas of the eastern sector of the Russian Arctic is 30% lower than for the other Arctic regions.