雷达资料提取散度的方法及其对一次暴雨过程的诊断分析

The Method of Extracting Data and its Diagnostic Divergence with the Radar Analysis on a Rainstorm

传统的散度判断方式是从雷达各仰角速度PPI图上分析，很大程度上依赖预报员的经验和主观判断。本文介绍了从雷达基数据中自动提取散度的一种方法和计算过程，并对山西一次暴雨过程进行诊断分析，结论表明：利用雷达基数据提取的散度所表征的动力学特征与大面积降水过程有较好的对应关系，并且提取方法操作简单，识别特征直观准确，在实际业务应用中也能大大节约预报员浏览雷达速度图像的时间，提高工作效率，可以作为其它诊断量和雷达产品的一种补充，有较高的业务推广价值。

Traditional way of divergence judgment is analyzing every elevation angle of the radar velocity PPI chart, which largely depends on the forecaster＇s experience and subjective judgments. This paper introduces a method and calculation process of extracting divergence automatically and it gives diagnostic analysis on a rainstorm oi Shanxi. The conclusion shows that the dynamic characteristics expressed by divergence which extracted by the radar base data has good correspondence with large area rainfall. Because of easy to extract and convenient to identify characteristics directly, it has wide application in actual operation for reducing the time significantly for forecasters to browse the radar velocity image, and can be used as a supplementto other diagnosis and radar products.