近60年永兴岛热带气旋降水的气候特征分析  

Climatic Features of Rainfall Induced by Tropical Cyclones in Yongxing Island in Recent 60Years

作　　者：周宇 凌芬曼 施晨晓 ZHOU Yu;LING Fenman;SHI Chenxiao(Sansha Metrological Service,Hainan,Sansha 573199;Key Laboratory of South China Sea Meteorological Disaster Prevention and Mitigation of Hainan Province,Haikou 570203;Hainan Meteorological Information Center,Haikou 570203)

机构地区：[1]海南省三沙市气象局,三沙573199 [2]海南省南海气象防灾减灾重点实验室,海口570203 [3]海南省气象信息中心,海口570203

出　　处：《气象科技》2021年第1期69-76,共8页Meteorological Science and Technology

基　　金：海南省气象局青年基金项目(HNQXQN201806)资助。

摘　　要：对1958—2019年期间,进入永兴岛及附近区域(11.5°~21.5°N,101.2°~117.5°E)范围内的热带气旋(Tropical Cyclone,TC)的气候特征进行分析,结果表明:①永兴岛平均每年受9.4个TC影响,TC有显著的下降趋势,以0.68个/10a逐渐减少,趋势系数为-0.406;②永兴岛TC路径分为5类:向西直行偏北类(A类)、向西直行偏南类(B类)、转向东北类(C类)、转向西南类(D类)、从西向东北类(E类),其中A类占比最大,占52.0%;③TC年均降水有显著的下降趋势,其回归系数为-61.76mm/10a,趋势系数为-0.270;④TC活动对永兴岛强降雨贡献最多,达到67.8%,其他天气系统对永兴岛强降雨的贡献仅为32.2%,年均TC强降雨日数为4.1d,非TC强降雨日数为2.8d,TC强降雨对总强降雨的贡献率无明显的趋势变化,其回归系数为0.57/10a,趋势系数为0.055,而TC强降雨日数的贡献率则呈现下降趋势,其回归系数为-4.7/10a,趋势系数为-0.335,通过α=0.01显著性检验。This paper analyzes the climatic characteristics of the tropical cyclone(TC)centers that entered the range of 10°×10°(longitude×latitude)around Yongxing Island from 1958to 2019.The results show that the Yongxing Island is influenced averagely by 9.4TCs in a year,and the TCs show a significant(α=0.01)decreasing trend in 0.67every decade(an trend coefficient of-0.406).This paper divides the TC paths in Yongxing Island into five categories:north-westward moving(A),south-westward moving(B),northeastward turning(C),southwestward turning(D),northeastward turning from west(E),of which Type A accounts for 52.0%.The annual rainfall caused by TCs exhibits a significant(α=0.05)decreasing trend(an regression coefficient of-61.76,an trend coefficient of-0.27).TC activities contribute the most to the heavy rainfall of Yongxing Island,reaching 67.8%,while the contribution of other weather systems is only 32.2%.The annual average number of rain days caused by typhoon is 4.1,while that caused by the others is 2.8days.The contribution of Typhoon Rainstorms to annual storm rainfall shows no obvious variation trend(an regression coefficient of 0.57,an trend coefficient of 0.055),but the contribution of typhoon rainstorm days to annual rainstorm days shows a significant(α=0.01)decreasing trend(a regression coefficient of 4.7,a trend coefficient of-0.33).

关 键 词：永兴岛 气候特征 趋势分析 台风降水 台风路径 

分 类 号：P466[天文地球—大气科学及气象学]