A New Insight into the Contribution of Environmental Conditions to Tropical Cyclone Activities  

作　　者：王元 宋金杰 伍荣生 

机构地区：[1]Key Laboratory of Mesoscale Severe Weather/Ministry of Education, and School of Atmospheric Sciences, Nanjing University

出　　处：《Acta meteorologica Sinica》2013年第3期344-355,共12页

基　　金：Supported by the National Basic Research and Development(973)Program of China(2009CB421502);National Natural Science Foundation of China(41275057and40830958);China Meteorological Administration Special Public Welfare Research Fund(GYHY200906011and GYHY201006007)

摘　　要：The changes of tropical cyclone （TC） activities in response to influencing environmental conditions have been paid more and more attention to in recent years, The potential contributions of single and multivariate environmental variables to annual TC frequency and intensity from 1970 to 2009 are investigated in this study. Instead of using correlation coefficient that assumes a set of samples satisfying the normal distribution, a quantitative measurement is formulated based on the information theory. The results show that dynamic environmental variables play an important role in variations of TC activities over the western North Pacific, North Atlantic, and eastern Pacific. These dynamic factors include wind shear between 850 and 200 hPa and 850-hPa relative vorticity. However, the effects of thermal factors on TC activities are distinct over different basins. The thermal environmental variables only have significant contributions to TC frequency and intensity over the eastern Pacific as well as to TC frequency over the North Atlantic. It is found that the primary factors influencing TC activities are indeed not the same over different basins because of the differences in atmospheric conditions and their changes across different areas. The effects of dynamic variables should be considered more in the regions such as the western North Pacific where the thermal conditions are always satisfied.The changes of tropical cyclone （TC） activities in response to influencing environmental conditions have been paid more and more attention to in recent years, The potential contributions of single and multivariate environmental variables to annual TC frequency and intensity from 1970 to 2009 are investigated in this study. Instead of using correlation coefficient that assumes a set of samples satisfying the normal distribution, a quantitative measurement is formulated based on the information theory. The results show that dynamic environmental variables play an important role in variations of TC activities over the western North Pacific, North Atlantic, and eastern Pacific. These dynamic factors include wind shear between 850 and 200 hPa and 850-hPa relative vorticity. However, the effects of thermal factors on TC activities are distinct over different basins. The thermal environmental variables only have significant contributions to TC frequency and intensity over the eastern Pacific as well as to TC frequency over the North Atlantic. It is found that the primary factors influencing TC activities are indeed not the same over different basins because of the differences in atmospheric conditions and their changes across different areas. The effects of dynamic variables should be considered more in the regions such as the western North Pacific where the thermal conditions are always satisfied.

关 键 词：tropical cyclone information theory ENTROPY 

分 类 号：P444[天文地球—大气科学及气象学]