摘要
采用美国联合台风警报中心(JTWC)提供的北印度洋1977-2008年热带气旋资料、NOAA提供的1982-2008年高分辨率合成资料和NCEP提供的1982-2008年全球再分析资料,对北印度洋上167个热带气旋个例进行了统计分析,结果表明:1)北印度洋热带气旋通常发生在阿拉伯海东部和孟加拉湾中部,阿拉伯海上活动的热带气旋要比孟加拉湾的频繁。由于印度半岛地形的影响,阿拉伯海上的热带气旋常常是沿着西高止山脉向西北方向运动,最后在巴基斯坦的南部登陆;孟加拉湾上热带气旋常常在孟加拉国和缅甸的南部登陆。2)小波分析结果表明,北印度洋热带气旋的年际变化具有2～4 a和4～8 a的显著周期。3)通过对热带气旋强度分析可以得出,有20个热带气旋(TC)达到了台风(TY)标准,3个达到强台风(STY)标准,18个达到超强台风(Super TY)标准。4)热带气旋出现频数季节性变化非常明显,春、夏、秋、冬呈现出高-低-高-低的形式,春季和秋季是北印度洋热带气旋高发季节。通过对500 hPa流场分析发现,500 hPa流场上辐合带的北进南退很好地解释了热带气旋的季节性变化。5)海温和季风对热带气旋发生频数有很大的影响,高海温和弱的垂直风切变有利于TC的生成。
Adopting the tropical cyclone（TC） data during 1977-2008 in North Indian Ocean provided by JTWC,high-resolution blended data during 1982-2008 provided by NOAA,global reanalysis data during 1982-2008 provided by NCEP,the paper statistical analyzes 167 tropical cyclone cases in North Indian Ocean and the results show that： 1）The origin area of tropical cyclone was lie in the eastern of Arabian sea and middle of Bengal Bay.The tropical cyclones in Arabian sea was more frequent than that in Bengal Bay,the moved path of tropical cyclones in Arabian sea was often along with the western Ghats and moved toward northwest,landed over south of Pakistan,and the tropical cyclones in Bengal Bay usually landed over Bengal and the south of Burma.2）By using wavelet analysis,we found that the inter-annual variation of tropical cyclone in North Indian Ocean had the character of 2-4 years and 4-8 years significant cycle.3）Analyzed the intensity of the tropical cyclone and found out that there were 20 tropical cyclones meet the typhoon standard,3 tropical cyclones meet the severe typhoon standard,18 tropical cyclones meet the super typhoon standard.4）Obvious seasonal variation exhibited the form of high-low-high-low in spring,summer,autumn and winter;the spring and autumn were the high frequently season of tropical cyclone.The results of analyzing the stream field in 500 hPa show that the variation of convergence zone in 500 hPa stream field well explained seasonal changes of tropical cyclone.5）Sea surface temperature and monsoon impacted on occurrence frequency of tropical cyclone,high sea surface temperature and weak vertical wind shear were in favor of occurrence of tropical cyclone.
出处
《气象与环境科学》
2011年第3期7-13,共7页
Meteorological and Environmental Sciences
基金
河南省气象局科研项目(Z200909)资助
关键词
北印度洋
热带气旋
统计特征
小波分析
North Indian Ocean
tropical cyclone
statistical character
wavelet analysis
