PDO和ENSO与大连6—9月降水关系分析

利用1905—2006年的太平洋年代际振荡(简称PDO)、ENSO和大连6—9月降水资料,分析三者之间的关系。结果表明:在PDO暖位相期,大连6—9月降水总体比常年偏少;PDO冷位相期,大连6—9月降水总体上比常年偏多;PDO与大连6—9月降水存在准周期对应关系,从PDO冷位相到暖位相,对应的大连6—9月降水距平8 a滑动平均曲线总体呈下降趋势。ENSO对大连6—9月降水的影响明显受PDO的调制,在PDO冷位相期,ENSO年大连6—9月降水总体上比常年偏多,而在PDO暖位相期,ENSO年大连6—9月降水总体上比常年偏少;不同强度和不同冷暖性质的ENSO,在不同PDO位相期内对大连6—9月降水的影响也各不相同。

Relationships of precipitation from June to September in Dalian with PDO and ENSO

Based on the Pacific Decade Oscillation(PDO) data and El Nino Southern Oscillation(ENSO) data as well as precipitation data from June to September in Dalian from 1905 to 2006,the relationships among them were analyzed.The results show that precipitation from June to September in Dalian is less than the normal average during the warm phase of PDO,and it is more than the normal average during the cold phase of PDO.There is a quasi-period between PDO and precipitation from June to September in Dalian.The corresponding precipitation anomaly from June to September in Dalian takes on a decreasing tendency by 8 years moving average from the cold phase to the warm phase of PDO.The effects of ENSO on precipitation from June to September in Dalian are controlled by PDO.Precipitation from June to September is more than the normal average in ENSO year during the cold phase of PDO,while it is contrary during the warm phase of PDO.The effects of different intensities and different ENSO on precipitation from June to September are different during the different phases of PDO.