Numerical simulation and temporal-spatial resolution analysis of tropical cyclone observation in GEO microwave satellite:a case study of typhoon "Fitow"

Temporal and spatial resolution for tropical cyclone observation play an important role in the design of radiometer used for observing tropical cyclone.In this study, the National Centers for Environmental Prediction (NCEP) final operational global analysis data prepared operationally every six hours was used as the initial field for mesoscale weather research and forecasting model (WRF) and drove the model to output atmospheric parameters such as hydrometeor content, temperature and humidity profiles at different time.The fast radiative transfer model for TOVS (RTTOV) developed by European Center for Medium-Range Weather Forecasts (ECMWF) was used to calculate brightness temperature.Then the simulated brightness temperature maps viewed from geostationary earth orbit at oxygen absorption band and water absorption band for different temporal and spatial resolutions were analyzed.Results indicate that the higher the level of tropical cyclone, the higher the spatial resolution is needed.Sensitivity to spatial resolution is gradually increased among oxygen absorption band, water vapor absorption band and atmospheric window band.In general, for a short observation period, tropical cyclone of lower level needs higher temporal resolution and observation in water vapor absorption band needs higher temporal resolution than that in oxygen absorption band.