摘要
中国大陆地区主要受季风影响,冬半年(11月至翌年4月)的降水很少,在冬季南支槽(SBT)是影响中国降水的主要系统之一。为了评估SBT对中国冬季降水的影响,对1981 2013年NCEP/NCAR逐日再分析资料采用客观方法识别了SBT的活动,对中国区域的逐日降水数据利用SBT的降水距平百分率,评估了SBT对不同区域的影响。结果表明,冬半年南支槽对降水影响最显著的区域为青藏高原和云南地区,有南支槽活动日的降水比无南支槽活动显著增加。对中国华南地区、东北地区和新疆地区,南支槽活动日较冬半年平均降水减少;南支槽影响区域的站点前50强降水日数的南支槽位置分析表明,当南支槽影响降水主要为青藏高原区域,南支槽更多地位于80°E附近,而75°E以西和85°E以东的南支槽活动偏少;当南支槽产生强降水主要为云南区域时,南支槽主要活动区域在90°E以东;南支槽位于不同位置时,其降水影响区有较大差异:当南支槽位于80°E以西,降水影响区主要位于西藏西部;南支槽位于80°E 90°E之间,降水影响区主要位于西藏中部、青海中南部地区和云南西北部地区;南支槽位于90°E以东,降水增加地区主要位于西藏中部地区、青海东部和云南。
China's Mainland（MC）precipitation is mainly affected by the monsoon,therefore MC precipitation is fewin wintertime（from November to next April）. Southern Branch Trough（SBT）is one of the main weather system affected precipitation in MC in wintertime. An objective method was used to identify the SBT activity dataset from NCEP / NCAR reanalysis dataset from 1981 to 2013. Using the SBT dataset and daily precipitation percentage anomaly data of MC,the influence of SBT to MC precipitation was shown. The most significant influence on the precipitation area of SBT is the Qinghai-Xizang Plateau（QXP）and the Yunnan（YN）region,a significant increase in daily precipitation SBT activity days than the ones with no SBT activity. In Northeast China and Xinjiang regions,SBT shows opponent influence with QXP and YN. SBT position of QXP and YN’s Top50 strong precipitation days showed that,when SBT’s impact region lays in QXP,SBT more located near 80°E,and SBT less activities in the west of 75°E and east of 85°E;when SBT mainly produce heavy rainfall in YN,SBT mainly located in east of 90°E. SBT located at different positions,it emerged different precipitation distribution. SBT located in west of 80° E,precipitation areas are mainly located in western Xizang. SBT Located between 80°E and 90°E,precipitation areas are mainly located in central Tibet,central south Qinghai and northwest YN. SBT located in east of 90°E,precipitation areas are mainly located in the central QXP and eastern YN.
出处
《高原气象》
CSCD
北大核心
2016年第6期1456-1463,共8页
Plateau Meteorology
基金
干旱气象科学研究基金项目(IAM201310)
关键词
南支槽
高原地区降水
冬半年日降水
槽客观识别
Southern branch trough（SBT）
Precipitation of plateau region
Wintertime daily precipitation
Objective identifying troughs
