Reprint573多波长微波幅射计在降雨临近预报的表现与应用陈柏纬第.PDFVIP

Reprint 573 多波長微波幅射計在降雨臨近預報的表現與應用 陳柏緯 第十九屆粵港澳氣象科技研討會， 中國，廣東陽江，2005 年 3 月1-3 日 降臨 力參量雷暴臨 數 例 數 來 數 兩 不臨 論 年利 流 里 力廓降臨 數 度 度廓 量 度廓數暴 暴不 數 里 數 率良 Performance and Application of a Multi-wavelength Microwave Radiometer in Rain Nowcasting P.W. Chan Hong Kong Observatory Abstract Thermodynamic parameters, such as K-index, are commonly used in the nowcasting of thunderstorms and heavy rain. They are derived from upper-air ascent measurements, which are only available twice a day and not sufficient for nowcasting purpose. This paper discusses the use of a multi-wavelength, ground-based microwave radiometer to provide frequently updated thermodynamic profiles of the troposphere up to 10 km for rain nowcasting during a field experiment in Hong Kong in 2004. The accuracy of the radiometers measurements is first established by comparing with the temperature and humidity profiles of upper-air ascents and the integrated water vapour derived from Global Positioning System (GPS) receivers. The humidity profile and K-index from the radiometer in a number of rainstorm cases are then studied. They are found to give useful indications of the accumulation of water vapour and the increasing degree of instability of the troposphere before the occurrence of the heavy rain. Moreover, the K-index derived from the radiometer measurement