ENSO与青藏高原积雪的关系及其对我国夏季降水异常的影响

Relationships Between ENSO and Qinghai-Tibetan Plateau Snow Depth and Their Influences on Summer Rainfall Anomalies in China

文章利用1979 2005年Nino3区海温时间序列资料和中国雪深时间序列资料,分析了Nino3区海温与青藏高原积雪之间的关系,两者对我国夏季降水的影响以及两者共同作用下对我国夏季降水的影响。分析结果表明:当前期冬春季Nino3区SST为强暖(强冷)事件与高原积雪显著偏多(显著偏少)共同作用的配置下,我国东部夏季雨带往往偏南(偏北)。从月时间尺度方面,揭示了前期冬春季ENSO和冬春季青藏高原积雪对我国长江以南地区降水异常的影响在夏季各月是不一致的,前期冬春季逐月Nino3区SST和冬春季逐月高原积雪对长江以南地区6月的降水都为正相关,而对8月的降水都为反相关,并且春季逐月Nino3区SST和冬春季逐月高原积雪对长江以南地区7月的降水也都为正相关,另外,春季Nino3区SST和春季高原积雪对长江以南地区6月和7月降水更为重要。

Based on the sea surface temperature（SST） in Nino3 region and snow depth from 1979 to 2005, relationships between ENSO and Qinghai-Tibetan Plateau（QXP） snow depth and their influences on summer rainfall in China were investigated,respectively.In addition,the joint influence of ENSO and QXP snow on summer rainfall in China was also analyzed. The results showed that the summer rainbelt in eastern China often moved southward（northward） only when a strong warm（strong cold） ENSO event and a heavy（light） QXP snow occurred simultaneously during previous winter and spring.Moreover,the monthly Nino3 SST and QXP snow during previous winter and spring both had a positive correlation with the June rainfall over southward of the Yangtze River, while they both had a negative correlation with August rainfall over southward of the Yangtze River.Furthermore, the monthly Nino3 SST during previous spring and the QXP snow during previous winter and spring both had a positive correlation with the July rainfall over southward of the Yangtze River.Moreover,the Nino3 SST and QXP snow during spring had a more important impact on June and July rainfall anomalies over southward of the Yangtze River.It clearly indicated that the impacts of previous ENSO and QXP snow on monthly rainfall anomalies over southward of the Yangtze River are different for each summer month.