近50年新疆气温和降水量变化及其与NAO指数的交叉小波谱分析

Relationship between the North Atlantic Oscillation and Climate Change in Xinjiang in Recent 50 Years

利用1961—2008年的逐日降水和气温资料,采用线性趋势、小波功率谱和交叉小波谱等方法分析了新疆降水和气温的变化,以及与北大西洋涛动(NAO)变化之间的关系。结果表明,近50年新疆存在降水增多和气温上升的趋势,有暖湿化现象,这与西北地区由暖干趋于暖湿的结论相一致。同时,新疆平均年降水量与NAO存在准2年和准6年周期,夏季降水量与NAO存在准3年和准5年周期,冬季降水量与NAO存在准3年周期。新疆年均气温与NAO存在准3年周期,夏季气温与NAO存在准3年周期,冬季气温与NAO存在准3年和准8年周期。新疆全年、冬季和夏季的降水与NAO的周期中,通过显著性检验的高值正相关大多集中在20世纪80年代;而气温与NAO的周期中,通过显著性检验的高值正相关也大多集中在80年代。

Utilizing the daily precipitation and temperature data in Xinjiang during 1961-2008 and re- gression analysis, wavelet power spectrum analysis, cross-wavelet transform methods, the relationships between NAO with temperature and precipitation in Xinjiang are analyzed. The result shows that NAO has strongly impacted temperature and precipitation in Xinjiang. And there is the increasing trend of tempera- ture and precipitation in past 48 years, which is agreed with the result from warm-dry to warm-wet in Northwest China. There are the quasi-2- and 6-year periods between the mean annual precipitation and NAO. In summer, there are the quasi-2- and 5-year periods for precipitation, and quasi-3-year period for temperature. But in winter, there is the quasi-3-year period for precipitation, and quasi-3- and 8-year peri- ods for temperature. Based on the different temporal scales, it significantly happened in 1980s, with the highly positive value of t^rmperature and precipitation.