南亚高压强度的年代际变化及可能原因分析  

A STUDY ON INTERDECADAL VARIATION OF SOUTH ASIAN HIGH AND ITS POSSIBLE CAUSE

作　　者：杨光[1] 李崇银[1,2] 谭言科[1] 

机构地区：[1]解放军理工大学气象学院,江苏南京211101 [2]中国科学院大气物理研究所LASG国家重点实验室,北京100029

出　　处：《热带气象学报》2013年第4期529-539,共11页Journal of Tropical Meteorology

基　　金：国家重点基础研究发展计划(2010CB950401)资助

摘　　要：利用NCEP/NCAR再分析资料和NOAA ERSST海温资料,对夏季南亚高压的年代际变化特征及其可能机制进行了分析。结果表明,南亚高压由弱到强的年代际转折发生在1970年代末,或者说南亚高压强度在1978年前后发生了年代际突变。对南亚高压偏弱和偏强两个阶段的对比分析表明,大气环流(包括风场、温度场和垂直运动场等)的异常形势和特征显著不同,几乎是相反的。夏季地表潜热通量异常的分析说明,夏季高原(特别是高原西北部)的地表热通量异常对南亚高压强度的年代际变化有重要影响;相对而言,地表感热通量异常可能对南亚高压强度的年代际变化起更重要作用。夏季热带印度洋海温的全区一致型模态在1970年代末也发生了明显的年代际变化,与南亚高压强度的年代际异常有很好的一致性,表明夏季热带印度洋海温一致型模态异常对南亚高压年代际变化有影响。The characteristics and possible physical mechanism of the interdecadal variation of the intensity of South Asian High（SAH） in summer are analyzed using the NCEP/NCAR reanalysis data and NOAA extended reconstructed sea surface temperature（SST） data. The results indicate that a remarkable interdecadal transition occurred in the late 1970s that increased the intensity of SAH, or, an abrupt climate change was around 1978. A comparative analysis between the low and high period of the SAH intensity shows that the related anomalous patterns of the atmospheric circulation （including wind field, air temperature field and vertical velocity field） are nearly opposite to each other. The surface latent heat flux anomalies over the plateau （especially in the northwest of the plateau） in summer exert great influence on the interdecadal variation of the intensity of SAH and the surface sensible heat flux anomalies play a more important role. Consistent with the interdecadal variation of the intensity of SAH, the basin-wide SST mode in the tropical Indian Ocean in summer also experienced a low to high transition in the late 1970s. To some extent, this can reveal the impact of the anomalous basin-wide SST mode in the tropical Indian Ocean in summer on the interdecadal variation of SAH.

关 键 词：南亚高压 年代际变化 大气环流 地表热通量 印度洋海温 

分 类 号：P434.5[天文地球—大气科学及气象学]