夏季青藏高原大气热源低频振荡与南亚高压东西振荡的关系  

Relationship between Low-frequency Oscillations of Atmospheric Heat Source over the Tibetan Plateau and Longitudinal Oscillations of the South Asia High in the Summer

作　　者：王黎娟[1] 葛静[1] 

机构地区：[1]南京信息工程大学气象灾害教育部重点实验室/气候与环境变化国际合作联合实验室/气象灾害预报预警与评估协同创新中心/气候模拟与预测科技创新团队,南京210044

出　　处：《大气科学》2016年第4期853-863,共11页Chinese Journal of Atmospheric Sciences

基　　金：第三次青藏高原科学实验项目--边界层与对流层观测GYHY201406001;江苏省高校自然科学研究重大项目14KJA170004;江苏省自然科学基金项目BK20131432;江苏省"青蓝工程"项目;江苏省"333"工程项目~~

摘　　要：利用1983-2012年NCEP／NCAR逐日再分析资料对夏季青藏高原大气热源和南亚高压东西振荡的低频特征以及两者的关系进行了讨论，发现夏季青藏高原东部大气热源与南亚高压纬向运动的主要低频周期都是10～20d。在高原东部大气热源10-20d振荡峰值位相，青藏高原上空被低频气旋控制，高原西部被低频反气旋控制，导致南亚高压主要高压中心向西移动呈伊朗高压模态；在大气热源10-20d振荡谷值位相，低频环流形势完全相反，青藏高原上空被低频反气旋控制，高原西部被低频气旋控制，致使南亚高压主要高压中心向东移动呈青藏高压模态。高原热力场异常导致其上空暖中心变化从而引起的高层风场变化可以解释南亚高压的东西振荡。The NCEP/NCAR reanalysis daily data for the period of 1983-2012 has been exploited to analyze the characteristics of low frequency oscillations of the vertically integrated atmospheric heat source over the Tibetan Plateau （TP） and longitudinal oscillations of the South Asia high （SAH） in the summer. The relationship between them is also discussed. Results indicate that the major low frequency cycle of heat source over eastern TP and the longitudinal displacement of SAH both are about 10-20 d. At the peak phase of the 10-20 d low-frequency heat source oscillation in the eastern plateau in the summer, 10-20 d low-frequency cyclones are dominant over the TP while anticyclones are dominant over the western TP. As a result, the SAH moves westward and appears as Iran high. At the valley phase of the oscillation, the low-frequency synoptic circulation pattern is completely opposite to that at peak phase. TP is under control of low frequency anticyclones while the western TP is controlled by low-frequency cyclones. Under this situation, the SAH moves eastward and appears as the Tibetan High. Wind field variations caused by changes in the warm center above the TP due to the thermal field anomalies can explain the SAH longitudinal oscillation.

关 键 词：青藏高原 大气热源 准双周振荡 南亚高压 东西振荡 

分 类 号：P461[天文地球—大气科学及气象学]