摘要
利用中国气象局《台风年鉴》资料和NCEP/NCAR再分析资料,分析1968—2006年北半球夏季(6—9月)澳大利亚冷空气活动与西北太平洋夏季台风频次(WNPSTYF)的关系,并研究其影响的可能机制。结果表明,夏季澳大利亚东部对流层经向风年际增量变化与WNPSTYF年际增量变化呈显著正相关;西太平洋近赤道区对流层上层纬向风年际增量与同期WNPSTYF年际增量呈显著负相关。澳大利亚冷空气活动影响WNPSTYF的可能机理是:当澳大利亚东部从对流层低层至上层的经向风年际增量有南风异常时(此时澳大利亚西侧对流层上层有年际增量的北风异常),冷空气在向低纬移动过程中受热上升,同时因柯氏力向左偏转,并在对流层上层向中纬度辐散,导致110～160°E区间的南半球近赤道附近对流层上层纬向风年际增量的偏北东风异常;由于赤道上空大气运动的无旋转特性及连续性,北半球也会出现同向的纬向风年际增量异常。赤道附近对流层上层纬向风年际增量的东风异常产生纬向风的经向切变,使对流层上层出现涡度年际增量的负异常;对流层上层涡度年际增量负异常的抽吸作用导致对流层低层出现涡度年际增量的正异常,利于台风生成,导致台风年际增量偏多。反之亦反。
Using Chinese Meteorological Administration year-book typhoon data and NCEP/NCAR reanalysis data, the correlation between the cold air activity of Southern Hemisphere and western North Pacific （WNP） typhoon number during Boreal Summer （Jan.--Sept.） is analyzed. Possible impacting mechanisms are also studied. Results show that there is significant correlation between yearly increase of typhoon genesis over the WNP and that of meridional wind over eastern Australia in summer. Correlation is also significant between the typhoon genesis increase and zonal wind yearly increase near the equator from 110 ~ 160 ~E at upper levels. The likely affecting way is that the yearly increase （decrease） of meridional wind over eastern Australia turns left and rises （fails） around the equator, leading to yearly zonal wind increase （decrease） there, resulting in the vorticity yearly increase （decrease） over the WNP and eventually influencing the typhoon genesis there.
出处
《热带气象学报》
CSCD
北大核心
2013年第4期641-648,共8页
Journal of Tropical Meteorology
基金
海南省重点科技计划应用研究及产业化项目(ZDXM20130081)资助
关键词
气候学
联系
机理探讨
西北太平洋台风频次
澳大利亚冷空气活动
climatology
connection
mechanism probing
Northwest Pacific typhoon number
Southern Hemisphere cold air activity
