应用NCAR CAM3全球大气环流模式以及NCEP/NCAR再分析资料,研究了不同海域(全球、热带外、热带、热带印度洋—太平洋、热带印度洋及热带太平洋)的海表温度异常对夏季南压高压年代际变化的影响。结果表明,全球、热带、热带印度洋—太平洋和热带太平洋这些海域的海表温度异常都对南亚高压强度、面积、南界、西伸脊点和东伸脊点的1970s中后期年代际变化有重要影响:热带太平洋是关键海区,其海表温度第三模态(“三明治”式异常分布型)的变化与南亚高压的这些特征指数的年代际变化关系密切;热带印度洋的海表温度异常,主要是其第一模态(热带印度洋全区一致变化型)的变化与南亚高压强度、面积、南界和西伸脊点的年代际变化关系较密切,热带印度洋也是影响南亚高压年代际变化的关键海区;这两个关键海区的海表温度异常对南亚高压年代际变化影响的主要差异在于:热带太平洋海表温度异常能对南亚高压的东伸脊点的年代际变化有重要影响,而热带印度洋的海表温度异常对其影响小;热带太平洋和热带印度洋这两个海区的海表温度异常均可通过影响热带对流层大气温度的变化进而使南亚高压发生变化;热带外的海表温度异常对南亚高压的年代际变化影响小。
By using the NCAR CAM3 global atmospheric circulation model and NCEP/NCAR rean- alysis data, the Sea Surface Temperature Anomaly (SSTA) effects in different sea areas (global, extra- tropical, tropical, tropical Indian ocean-Pacific, tropical Indian ocean and tropical Pacific) on the interdecadal variation of the South Asia High (SAH) were analyzed. Results suggest that the global, tropical, tropical Indian ocean-Pacific and tropical Pacific have great effects on the interdecadol variation of the in- tensity,area,south,west and east borders of SAH in late 1970s. The tropical Pacific is a key sea area whose third mode of the SSTA has a close association with the interdecadal variation of these SAH indi- ces. The change of SSTA in tropical Indian ocean is associated with the interdecadal variation of the in- tensity, area, south and west borders of SAH, due to its first mode shown by the in-phase SSTA in tropi- cal Indian ocean, which indicates that this sea area is also a key area in affecting the interdecadal varia- tion of SAH. The main difference between the effects of the tropical Pacific and tropical Indian ocean on the interdecadal variability of SAH is that the former has important effect on the interdecadal variability of eastward extension of SAH and the latter is weaker. The SSTAs in the tropical Pacific and tropical Indian Ocean impact the SAH through affecting the changes of tropical tropospheric temperature driven by these SSTAs. The extra-tropical SSTAs have the weaker impact on the SAH.