| 摘要: | 研究期間：10108~10207;Heavy rainfall brought by typhoons and mesoscale convective systems (MCSs) are the very important water resources for Taiwan. However these rainfall events often cause floods and mudflows, and then severe causalities. Therefore, an early detection technique to find these heavy rainfall systems is crucial for disaster warning and mitigation. Most typhoons occur over open oceans, making the traditional weather observation data is not enough. Meanwhile, MCSs often develop in a very short period, making the traditional sounding observations can not have a well temporal coverage. Fortunately current satellite techniques can provide wide and good temporal resolution coverage to watch these rainfall systems. Therefore, the aim of this study is to employ satellites to retrieve the air-sea parameters, and further use the parameters to monitoring the rainfall systems in typhoons and MCSs. In typhoons, the air-sea parameters derived from SSM/I, SSMI/S, TMI and AMSR-E microwave data will be analyzed to understand the air-sea interactions under different atmospheric conditions and different typhoon life stages, to find possible typhoon precursors. The wind speed fields from QuikSCAT, ASCAT and Atmospheric Motion Vectors, and the geostationary satellite imagery also will be used. With the satellite-derived thermal and dynamic environmental fields to find the detect the early typhoon formation. In MCSs, the objective optimal index (OPI) (Liu et al., 2002) will be used to retrieve the air-sea parameters (sea surface temperature, near sea surface temperature, humidity and wind speed, latent and sensible heat fluxes) with SSMI/S, TMI, AMSR-E satellite data along with the atmospheric stability index from AMSU and MODIS-derived temperature/humidity profiles, then be assembled to an OPI value to detect the early MCSs and monitor their evolution. |
