Comparison of IASI temperature and moisture retrievals with radiosonde measurements and numerical model outputs over East Asia

Temperature and moisture profiles retrieved from Infrared Atmospheric Sounding Interferometer (IASI) were evaluated by using radiosonde observations and model forecasts over East Asia. We used the level 2 products provided by National Oceanic and Atmospheric Administration/National Environmental Satellite, Data, and Information Service (NOAA/NESDIS) for IASI retrievals. Numerical model outputs from Regional Data Assimilation and Prediction System (RDAPS), Korea Weather Research and Forecasting (KWRF), and UK Met Office model (UM) were also matched with the satellite and radiosonde profiles for examining the model performances, in comparison with satellite data. The statistics of temperature and water vapor profiles were calculated by using the collocated radiosonde measurements as a reference. Both of temperature and moisture retrievals from satellite showed degraded performances over land and in dry conditions. Moist bias of the lower-troposphere is significant in dry condition especially over land, whereas dry bias of the mid-troposphere is significant in moist condition both over land and ocean. Based on the validation results, we discuss which factors can contribute to the improvement of the retrieval results over East Asia.