中国24h台风路径预报难点及其大尺度环流分析  

Analysis on difficulty of 24 h typhoon track forecast in China and associated large- scale circulation

作　　者：杨琼琼[1] 吴立广[1] 

机构地区：[1]南京信息工程大学气象灾害省部共建教育部重点实验室,南京210044

出　　处：《气象科学》2015年第4期389-397,共9页Journal of the Meteorological Sciences

基　　金：国家重点基础研究发展计划(973计划)项目(2009CB421503)

摘　　要：主要分析了2005—2012年中国24 h台风路径预报误差较大的样本及其对应的大尺度环流特征。基于850 h Pa风场的低通滤波等分析发现:去除占总数3.9%的预报误差最大样本后,平均预报误差可以减小8.5%。这些预报误差最大的样本中有近60%呈现为移向误差较小、移速较观测慢的特点。与之相对应的大尺度环境场可分为气旋性环流、弱背景场和副热带高压西侧3类。气旋性环流包含近3/4的样本,其中又有一半受季风涡旋的影响。平均移动速度分析表明,这些台风起报时刻前后,平均移速的突然增加是预报移速较慢的主要原因,这是中国台风24 h路径预报的主要难点之一。In this paper, the cases with larger errors in 24 h typhoon tracks forecast in China during 2005-2012 and their associated large-scale circulation characteristics are mainly examined. It is found that the mean forecast errors could decrease by 8.5% after removing the 3.9% largest forecast error cases based on the low-pass filtering of 850 hPa wind field. In about 60% cases the trends of small direction er- rors and lower transportation speed are apparent. The associated large-scale surrounding flows can be classified as cyclonic circulation, weak background and the west side of subtropical high, respectively. The cyclonic circulation represents three quarters of the total cases, where half of them are affected by monsoon gyre （MG）. Mean transportation speed analysis shows that the sudden increasing of typhoon mean transportation speed around the starting time of forecasting is the main reason of lower forecast speed, which is one of the major difficulties in the 24 h typhoon tracks forecast in China.

关 键 词：台风 预报误差 大尺度环境场 季风涡旋 

分 类 号：P457.8[天文地球—大气科学及气象学]