北上热带气旋气候特征分析

北上热带气旋是影响我国华北和东北地区的重要天气系统,其带来的大风和暴雨,常常造成我国北方地区的风灾和水灾。利用建国以来56 a的气象资料,对影响我国的北上热带气旋进行气候分析。结果表明:从时间上看,平均每年约有3个北上热带气旋,最早出现在5月下旬,最晚出现在11月中旬,其中以7月和8月为最多;每年6—9月为北上热带气旋登陆季节,7月和8月登陆的热带气旋占85%。从强度上看,能够到达北方的热带气旋一般都是较强的热带气旋,在进入北上热带气旋定义区后,总体强度明显减弱,但在进入黄渤海时仍能够达到台风的强度;与北上热带气旋相比,北上登陆热带气旋的强度更大。统计分析发现,在辽宁和华北登陆的热带气旋,其强度大于在山东半岛登陆的热带气旋。北上登陆热带气旋和北转向、中转向的热带气旋一般均能产生暴雨和大风。

Climatic characteristics of north-going tropical cyclone

North-going tropical cyclone is an important weather system impacting north China and northeast China.It could bring the gale and rainstorm and result in wind disaster and flood disaster in north China.Climatic characteristics of north-going tropical cyclone were analyzed with meteorological data from 1949 to 2004.The results indicated that there were 3 north-going tropical cyclones every year on average.The first one occurred in the last ten-day of May,the last one was in the middle ten-day of November,and most were in July and August.The landing season of north-going tropical cyclone was from June to September.85% of north-going tropical cyclones landed in July and August.The tropical cyclones which could reach north China were relatively strong,and their intensities were weakened obviously after entering the defined area of north-going tropical cyclone.But they were still able to reach the intensities of typhoon when they entered Huang Sea and Bo Sea.The intensity of landing north-going tropical cyclone was stronger than that of north-going tropical cyclone.The intensities of tropical cyclones landing at Liaoning province and north China were stronger than that of landing at Shandong Peninsula in terms of statistical analysis.The landing north-going tropical cyclone,north-turning tropical cyclone and middle-turning tropical cyclone were commonly able to bring about rainstorm and gale.