西北太平洋热带气旋频数和强度变化趋势初探  

Climatological Characteristics of Tropical Cyclones in the Northwestern Pacific

作　　者：赵珊珊[1] 高歌[1] 孙旭光[2] 杨修群[2] 

机构地区：[1]国家气候中心气候应用与服务室,北京100081 [2]南京大学灾害性天气气候研究所,南京210093

出　　处：《应用气象学报》2009年第5期555-563,共9页Journal of Applied Meteorological Science

基　　金：国家科技支撑计划课题(2007BAC29B02);国家自然科学基金项目(40523001;40730953;40425009;40405010);中国气象局行业专项(GYHY200706010;GYHY200706005)共同资助

摘　　要：利用1951—2006年西北太平洋（含南海）热带气旋资料,研究了不同强度热带气旋的气候变化特征。结果表明：超强台风（近中心最大风速≥58 m/s,简称超强台风Ⅱ）频数、强度和初、终旋日期的变化特征都不同于其他级别热带气旋;西北太平洋热带气旋的总频数有长期减少趋势,主要由热带低压和超强台风Ⅱ的长期减少趋势引起;随着热带气旋强度增强,出现月最大频数的月份逐渐推迟;超强台风月频数最大值发生在秋季;超强台风Ⅱ频数的年变化与除了超强台风Ⅰ（近中心最大风速为51-58 m/s）外的其他级别热带气旋反相关;受超强台风Ⅱ减少影响,热带气旋年平均最大风速有减小的长期趋势;热带气旋的初、终旋日期没有显著的长期变化趋势,但超强台风Ⅱ的初旋日期有推迟趋势,终旋日期有提前趋势,发生时间缩短。Climatological characteristics of tropical cyclones in the Northwestern Pacific during 1951—2006 are investigated based on the tropical cyclone best track data from China Meteorological Administration.Tropical cyclones are classified into 6 different categories to study the long-term variation under the global warming background.From 1951 to 2006,nearly 33.9 tropical cyclones occur in the Northwestern Pacific every year.Tropical depressions contribute 18.8% and super typhoons contribute 17.8%.The total frequency of tropical cyclones in the Northwestern Pacific decreases since 1950s and the decreasing trend is 1.8 times every 10 years.Frequency of tropical cyclones is highest in 1967 and lowest in 1998.The decrease trend of tropical cyclones frequency is mainly caused by tropical depression and super typhoon Ⅱ（maximum wind ≥58 m·s-1,super typhoon Ⅱ for simple）.The decrease trend of super typhoon Ⅱ is most remarkable.Contributions of tropical depression and super typhoon Ⅱ frequencies decrease while contributions of other categories increase.Characteristics of frequency,intensity,the first and last date of super typhoon Ⅱ are different from those of other categories.About 56.3% of tropical cyclones in the Northwestern Pacific appear in summer season,especially in August.The average monthly frequency is 7.9 in August and 0.3 in February.With the growing intensity of tropical cyclone,the maximum frequency postulate from August to October.The maximum frequency of super typhoon appears in autumn while those of other categories appear in August.Monthly frequencies of tropical depression and super typhoon Ⅱ take on decrease trends in autumn while those of other categories don＇t show remarkable trends.The annual variations of super typhoon Ⅱ are negative related with the annual variations of other categories except super typhoon Ⅰ.Yearly mean maximum speed and minimum depression of tropical cyclones show a decrease trend.Yearly maximum speed of tropical cyclones decreases about 6.5 m·s-1 every

关 键 词：热带气旋 超强台风 长期变化趋势 初旋日期 终旋日期 

分 类 号：P444[天文地球—大气科学及气象学]