摘要
应用NCEP/NCAR再分析资料,对冬季登陆我国的0428和7427号台风过程的冷空气作用和水汽特征进行了研究,结果表明:在初冬季节,东亚大槽引导的冷空气可以到达热带洋面的台风外围;台风与出海高压相向而行,外围气压梯度增强对台风强度的加强和维持起作用;弱冷空气在低层侵入仍在温暖海面上的台风,气旋扰动加强使台风加强;当强冷空气侵入台风中心中层时会破坏其暖心结构,使其填塞消亡。台风生成于水汽通量辐合带内,其生成和发展引起水汽汇合的扰动,加强水汽的辐合,使水汽辐合带加强;一旦台风脱离水汽辐合带后,不能继续获取大量水汽,则会逐渐减弱消亡;冬季台风过程没有强的水汽输送带。
Using NCEP/NCAR reanalysis data, the role of cold air and moisture characteristics during the evolution of two typhoon cases of Nanmadol（0428） and Irma（7427） which made landfall on China in wintertime are investigated. The results are shown as follows. （1） The East Asia trough steered the cold air into tropical oceans in early winter. The typhoons moved in opposite directions with highs moving out to sea and the enhancement of the pressure gradient at the periphery of typhoons played a role in maintaining and strengthening the intensity of the typhoons. The intrusion of weak cold air into the low levels of the typhoons could strengthen them by improving the cyclonic disturbance when they were still over the warm sea surface. When the cold air was strong enough and intruded into the typhoon centers, the warm cores were damaged, stuffed before dissipation. （2） The typhoons were formed in a convergence zone of moisture flux and their development could enhance the disturbance of water vapor convergence, thus strengthening the moisture convergence zone. However, when the typhoons were outside the moisture zone, they could not gain sufficient water vapor and became weak. There were no belts of strong moisture transportation during the typhoon processes in wintertime.
出处
《热带气象学报》
CSCD
北大核心
2009年第5期541-550,共10页
Journal of Tropical Meteorology
基金
国家重点基础研究发展计划项目(2009CB421505)
“十一五”国家科技支撑计划重点项目(2006BAC02B)
国家自然科学基金项目(40775058)共同资助
关键词
台风
冷空气
水汽
冬季
typhoons, cold air, water vapor, wintertime
