摘要
南海土台风,是在南海局地形成的热带气旋的统称。本文选用1949—2014年CMA-STI整编的"热带气旋最佳路径数据集",对研究区域范围(5°~22.5°N、105°~120.5°E)的南海土台风强度及强度变化特征进行了探讨。结果表明:(1)南海土台风强度随时间的变化曲线呈近似对称的"漏斗状",即强度从弱—强—弱的变化,在最大强度前后6h时域内强度变化最显著,夏季台风强度变化比冬季快。(2)土台风强度存在1个增强中心,位于海南岛以东的南海北部近海区域,在中国华南沿岸陆区则减弱明显;台风增强/减弱区域随着季节变化而南北移动,夏季主要在北部近海/近岸区域18°~23°N附近,冬季随台风活动南移至10~18°N附近靠近西部近海/近岸区域,且冬季的平均减弱速率较夏季大。(3)东向移动的土台风最大强度一般比西向移动的强,其中夏季东移台风平均强度最大,冬季西移台风强度最小;夏季东移台风最大强度前后强度变化最快,冬季西移台风变化最慢;夏季西移台风强度分布呈北强南弱、东移台风强度呈东北向带状分布,冬季东、西移台风强度分布皆呈西强东弱,这种空间分布差异,主要是台风移动路径随季节变化而形成的。(4)海上活动时间的长短与台风最大强度的大小、变化幅度成正比。海上活动时间较短的台风,以西行路径为主,强度的分布较均匀,平均强度较弱,增强/减弱中心较多而小,增强/减弱速率较慢;反之,海上活动时间较长的台风,以东行路径居多,强度的分布呈多中心状,平均强度较强,增强/减弱中心较集中且广阔,增强/减弱速率较快。
The local typhoon refers to the tropical cyclone formed in the South China Sea.1949-2014CMA- STI compiled "best track dataset for tropical cyclone"was chosen in this study,the local typhoon intensity and intensity change characteristics on the scope of the study area (5°-22.5°N,105°-120.5°E)were discussed. The results showed as follows:(1)The time curves of local typhoon intensity were similar to symmetric funnel-shape,that was changed from weak-strong-weak,intensity change was the most significant before and after 6h in maximum intensity,and intensity change in summer was quickly than in winter.(2)The local typhoons had one intensified centers,located in the east of Hainan Island coastal area,but which decreased obviously near the south China coastal Iand area;further analysis showed that the typhoon intensified/ weakened area moved with the changing seasons,in the summer it was mainly in the north offshore/nearshore area near 18°-23°N,while in the winter it was close to the west offshore/nearshore area near 10°-18°N,and the average decreased rate in winter was bigger than that in summer.(3)Furthermore,the eastward local typhoon intensity was generally stronger than that of westward,average intensity of summer eastward typhoon was the largest and that of winter westward typhoon intensity was the least;around the maximum intensity,the summer eastward typhoon intensity change was the fastest and winter westward typhoon was the slowest.Summer westward typhoon intensity distribution was stronger in the north,and eastward
作者
薛淑君
XUE Shu-jun(College of Atmospheric Science,Chengdu University of Information Technology,Chengdu 610225,China;State Key Laboratory of Satellite Ocean Environment Dynamics,Hangzhou 310012,China;Second Institute of Oceanography,SOA,Hangzhou 310012,China)
出处
《海洋学研究》
CSCD
北大核心
2018年第3期1-16,共16页
Journal of Marine Sciences
基金
国家重点基础研究发展计划资助(2013CB430301)
关键词
台风
强度
强度变化
南海
typhoon
intensity
intensity change
the South China Sea