Improved assimilation of data from China's FY-3A microwave temperature sounder

Abstract

The FY-3A microwave temperature sounder (MWTS) suffers from nonlinearities in the calibration of the radiometer and uncertainties in the radiometer passbands. Corrections have been developed and are assessed here by comparing recalibrated MWTS data with equivalent advanced microwave sounding unit-A (AMSU-A) observations. The corrections are effective in improving the first guess departure statistics for MWTS, relative to the original uncorrected data, to values close to those for AMSU-A equivalent channels. In observing system experiments, MWTS observations improve the first guess fits for AMSU-A observations. Forecast verification shows a systematic improvement by using the recalibrated data, e.g. forecasts of 200 hPa geopotential are improved to Day 3 in the SH by approximately 1%. © 2011 Royal Meteorological Society.