Experimental Research Of The Retrieval Of Cloud Microphysical Parameters By FY-2C Geostationary Satellite Data

The cloud microphysical parameters are important to the research of climate, weather, environment, and weather modification. According to the fact that the reflection function of clouds at a nonabsorbing band in the visible wavelength region is primarily a function of the cloud optical thickness, whereas the reflection function at a water(or ice) absorbing band in the near infrared is primarily a function of cloud particle size, cloud effective particle radius and cloud optical thickness are retrieved from FY-2C geostationary meteorological satellite VIS, IR1 and mid-IR channels based on the radiative transfer module, SBDART. The liquid water path is computed using the two retrieved parameters, and the cloud microphysical parameter product which is applied to our country and is able to real-time run is developed.Algorithms and process for retrieval are presented, the effects of other factors (surface albedo, cloud bottom height, solar zenith angle, satellite zenith angle, relative azimuth angle) on the retrieval results besides cloud effective particle radius and cloud optical thickness are analyzed, and some sensitivity experiments are carded out for special aims, the results show the effects of other factors are smaller than those of cloud effective particle radius and cloud optical thickness on the two channel reflection function respectively.Then, considering the applications of the cloud microphysical parameters in the field of artificial precipitation, a sheet cloud precipitation is selected to do some research. By comparing with the MODIS product, radar data, and Micaps data of the same time level, it shows good consistency validating the feasibility and reliability of retrieval. Furthermore, the probable reasons of error are discussed. Finally, by two cases with different properties of land rain and sea rain, the typical characteristics are showed on the diagrams of cloud effective particle radius and their causes of formation are deeply interpreted. Typhoon is a kind of hazardous weather system that affects the coastal provinces, so the retrieval characteristics of a typhoon case are selected to analyze in sea cases, while the retrieval characteristics of precipitation over a wide-area are selected to analyze in land cases.