基于两套资料集的海南岛热带气旋降水特征对比

Characteristics Comparison of Tropical Cyclone Precipitation in Hainan Island Based on Two Datasets

利用2009—2018年两套不同站点数量的降水数据集(CP和TP),对比分析海南岛热带气旋降水特征。结果表明:(1)两套资料统计的最大降水值存在显著差异,且TPmax>CPmax,而站点平均降水值无显著差异,且TPavg<CPavg。(2)近10 a来,CP和TP最大降水值、站点平均降水值一致呈不显著下降趋势,TP的下降幅度比CP大。(3)两套资料的平均降水、极端降水及其出现频率均呈"西高东低"的空间分布特征,但大值中心和强度有所差别。相比TP,CP高估了西部沿海和内陆的平均降水以及西部内陆的极端降水,低估了山区东部和西南部的平均降水以及西部沿海、中部内陆的极端降水。站点密集的东北角、东南沿海、西南沿海是平均降水、极端降水及其频率的低值区,是导致站点平均降水TP<CP的主要原因。(4)热带气旋经过山区以北时易导致TP呈现"西高东低、南少北多"的分布特征,而经过山区或其以南时易造成"南多北少"的分布特征。(5)海南岛热带气旋TP降水与影响时长、强度存在显著正相关,而极端降水与强度的相关性更加显著。

Based on two precipitation datasets from national(CP)and automatic(TP)weather stations with different numbers,the precipitation characteristics of tropical cyclones were compared in Hainan Island.The results are as follows:(1)The maximum precipitation of TP and CP datasets had significant difference in Hainan Island,and the former was greater than the later,while the difference of station-average precipitation between TP and CP wasn’t obvious,and the former was less than the later.(2)The maximum and station-average precipitation of CP and TP decreased consistently from 2009 to 2018,and the decrease of TP was more obvious than that of CP.(3)The average precipitation,extreme precipitation and its occurrence frequency of two datasets were high in the west and low in the east of Hainan Island in space,but the centre location with high value and its intensity of two datasets were different.Compared with TP,the average precipitation in western coastal and inland areas and the extreme precipitation in western inland areas were overestimated by CP,while the average precipitation in eastern and southwestern mountainous region and the extreme precipitation in western coastal and central inland of Hainan Island were underestimated by CP.The low values of average precipitation,extreme precipitation and its occurrence frequency appeared in northeastern edge and southeastern and southwestern coastal of Hainan Island with dense stations,which resulted in station-average precipitation of TP less than that of CP.(4)The precipitation based on TP was more in northern and western and less in southern and eastern part of Hainan Island when the tropical cyclones passed through the north side of the mountainous region.However,when the tropical cyclones crossed the mountainous region or its southern side,the precipitation was likely to form another distribution pattern with more in southern and less in northern part of Hainan.(5)The precipitation of tropical cyclones based on TP data had significantly positive correlation with impacting hours and intensity,and the correlation between extreme precipitation and intensity of tropical cyclone was more significant.