大气科学进展（英文版）
大氣科學進展（英文版）
대기과학진전（영문판）
ADVANCES IN ATMOSPHERIC SCIENCES
2010年
1期
177-184
,共8页
阿留申低压%澳大利亚%年际时间尺度%夏季风%ASM%流通方式%下沉运动%季风降水
阿留申低壓%澳大利亞%年際時間呎度%夏季風%ASM%流通方式%下沉運動%季風降水
아류신저압%오대리아%년제시간척도%하계풍%ASM%류통방식%하침운동%계풍강수
North Pacific%Aleutian Low%Australian monsoon%interannual variability
The relationship between the boreal winter （December, January, February） Aleutian Low （AL） and the simultaneous Australian summer monsoon （ASM） is explored in this study. A significant correlation is found between the North Pacific index （NPI） and ASM index, the bulk of which is attributed to the significant correlation after late 1970s. Significant differences in precipitation and outgoing long-wave radiation between typical negative and positive NPI years appear over the ASM area. A regression analysis of the circulation pattern against the NPI during the three months is performed separately. We propose that the NPI is related with the ASM circulation possibly through the changes in the upper level westerly jet. In a typical negative NPI （strong Aleutian Low） year, the jet is greatly reinforced and the anomalous anticyclonic circulation to the south is thus excited, from which the easterly wind anomalies flowing into the ASM region emanate. Further, strong sinking motion over the northern entrance region of the jet is enhanced, and the local Hadley circulation anomaly between the ASM region and the coast of East Asia is strengthened. In this way, anomalous upward motion over the ASM area can thus be strengthened, and the convective activity intensified. Then the monsoon rainfall over ASM area is increased. An ＂asymmetric＂ connection between AL and the monsoon is found in this study.
