Near Real‐Time Sensing of PWV from SGCAN and the Application Test in Numerical Weather Forecast
Near Real‐Time Sensing of PWV from SGCAN and the Application Test in Numerical Weather Forecast
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DOI：
10.1002/cjg2.3542
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发表时间：
2004-07
期刊：
影响因子：
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通讯作者：
Shuli Song;Wen-yao Zhu;Jincai Ding;X. Liao;Zhongni Cheng;Q. Ye
中科院分区：
文献类型：
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作者：
Shuli Song;Wen-yao Zhu;Jincai Ding;X. Liao;Zhongni Cheng;Q. Ye
对2002年夏季上海GPS综合应用网（SGCAN）的GPS数据进行了分析。IGS的超高速轨道直接用于实时处理。可靠的可降水量（PWV）系列可以在远程站点的帮助下获得。考虑到海潮的影响，可以提高PWV的精度。GPS/PWV和无线电探空的观测值相差约2mm。MM5与GPS/PWV输出的对比表明，GPS可以作为近实时验证MM5预报的一种手段。整个梅雨季节的连续GPS/PWV序列较详细地反映了2002年夏季长三角梅雨季节前后PWV的变化过程。GPS/PWV的变化表明，梅雨季节从西南向东北开始，在7 ~ 8 h左右结束。梅雨季节雨带在长江三角洲和淮河地区之间来回移动。PWV峰值和一小时雨量的统计说明GPS/PWV短时预报暴雨的能力。采用Cressman方法将GPS/PWV插值到背景场网格点上，优化数值预报模型的湿度条件。提高了数值预报的精度。本文通过一个实例说明GPS/PWV在改进数值预报方面的潜力。
GPS data from Shanghai GPS Comprehensive Application Network (SGCAN) in summer of 2002 are analyzed. The ultra-rapid orbits of IGS (IGU) are used directly in real-time processing. Reliable Precipitable Water Vapor (PWV) series can be obtained with the assistance of remote stations. Considering the effect of ocean tide, the accuracy of PWV can be improved. The difference between GPS/PWV and Radiosonde observations is about 2mm. Comparison between the output of MM5 and GPS/PWV shows that GPS can be regarded as one means to verify the forecast of MM5 in near real time. Continuous GPS/PWV series in the whole Meiyu season reflect the changing processes of PWV in detail before and after the onset of Meiyu Season in Yangtze River Delta in 2002 summer. The variation of GPS/PWV shows that the onset of Meiyu season was from southwest to northeast and completed in about 7–8 hours. Rainband moved back and forth between Yangtze River Delta and Huaihe area in Meiyu season. The statistics of PWV peaks and one-hour rain explains some short-term forecast ability of GPS/PWV for rainstorms. The humidity condition of numerical forecast model is optimized after GPS/PWV being interpolated to the gridpoints of background field using Cressman method. The accuracy of numerical forecast is improved. One example is provided in this paper which shows the potential of GPS/PWV for improving numerical forecast.