X波段雷达OHP产品在台风降水中的检验评估

Evaluation of X-Band Radar OHP Products during Typhoon Precipitation Events

摘要: 本文通过2024~2025年对台州产生影响的7次台风降水X波段天气雷达的雷达OHP产品和CMPAS逐小时降水产品的检验分析发现：1) 小雨和中雨量级的降水准确率最高，其次是大雨和暴雨，大暴雨准确率最低。2) ETS评分小雨和中雨的降水准确率和TS相似，但是相对于TS评分都有一定程度的下降，尤其是小雨量级，说明小雨量级存在较多空报，大雨和暴雨量级下降却不明显，说明在大雨和暴雨的预报时具有更高的可信度，较少有空报。3) 台风期间，BIAS基本都在1以下，说明雷达OHP产品判断的降水出现频次比实际的降水频次少，尤其是康妮台风对中雨、大风、暴雨估测出现次数严重减少；同时降水量级的估计普遍偏小。4) 通过误差分析，降水估测公式单一、非降水回波以及降水粒子与雷达测量的空间差异都是导致其误差的原因。

Abstract: This paper presents a verification analysis of the X-band weather radar OHP products and CMPAS hourly precipitation products for seven typhoon precipitation events affecting Taizhou from 2024 to 2025. The key findings are as follows: 1) The precipitation detection accuracy is highest for light and moderate rain, followed by heavy rain and torrential rain, with the lowest accuracy observed for exceptionally heavy rain. 2) The ETS scores for light and moderate rain show similar accuracy trends to TS scores but exhibit a certain degree of decline, particularly for light rain, indicating a higher frequency of false alarms at this intensity. In contrast, the decline is less pronounced for heavy and torrential rain, suggesting higher forecast reliability and fewer false alarms for these intensities. 3) During typhoon events, the BIAS is generally below 1, indicating that the frequency of precipitation detected by the radar OHP products is lower than the actual frequency. This underestimation was particularly severe for moderate rain, strong winds, and torrential rain during Typhoon Kong-rey. Concurrently, the estimated precipitation amounts are generally biased low. 4) Error analysis reveals that contributing factors include the singularity of the precipitation estimation formula, non-precipitation echoes, and spatial discrepancies between precipitation particles and radar measurements.