夏季菲律宾低空越赤道气流与南半球大气环流的关系

摘要

Based on the 1950-2009 NCEP/NCAR reanalysis data, the intensity index of Philippines cross-equatorial flow is defined to analyze its relationship with Southern Hemispheric atmospheric circulation. Results show that Philippines cross-equatorial flow is affected by the polar high, the depression belt around the pole, and the mid-latitude subtropical high in the lower troposphere, and also affected by the huge low pressure system around the pole in the upper troposphere over the Southern Hemisphere. Southern Hemispheric atmospheric circulation influences the cross-equatorial flow primarily through the adjustment of the Antarctic Oscillation which affects Australian high. And there is an about four-year delay from the adjustment of the Antarctic Oscillation to the responses of the cross-equatorial flow and the Northern Hemispheric atmospheric circulation. The strength and position changes of Australian high have important influence on the cross-equatorial flow , and the key area locates in the northwest ocean of Australian high.%采用NCEP/NCAR再分析资料，定义了1950-2009年菲律宾越赤道气流强度指数，并研究其与南半球大气环流的关系。结果表明，菲律宾越赤道气流受南半球低层极地高压、绕极低压带和中纬度副热带高压，以及高层巨大的绕极低压影响；南半球环流对菲律宾越赤道气流的影响主要是通过南极涛动的调整，对澳大利亚高压产生影响来发挥作用，从南极涛动发生调整到对越赤道气流及北半球环流产生影响，有约4a的时滞；澳大利亚高压强度和位置的变化对菲律宾越越赤道气流有重要影响，关键区位于澳大利亚高压西北方向的洋面上。