近年来,增温增湿趋势影响着新疆北部(以下称北疆)的生态系统与农牧业发展,有必要对北疆气候变化及其归因进行深入剖析。根据北疆地区23个台站月平均气温、降水资料和北极涛动指数(AOI)标准化序列资料,采用线性倾向估计、累积距平、滑动t检验、相关分析、小波变换等统计方法,分析了1965—2012年北疆地区气温与降水的变化特征及其对北极涛动(AO)的响应。结果表明:1北疆年平均气温与年降水量变化呈上升趋势,线性倾向率分别为0.41℃·(10a)(-1)及11.26 mm·(10a)(-1);二者发生突变时间分别在1988年和1986年前后;突变后,北疆春、秋、冬季增温显著,夏季气温增幅不明显;北疆降水量各季都有所增加,且以冬季增幅最大。2北疆气温、降水与AOI的变化周期具有一定程度的相似性:冬、夏季气温及降水与AOI在准3 a尺度周期上有很好的频域对应关系。3北疆冬季气温序列与AOI相关性较高;北疆冬季气温、降水与AO变化在多个周期尺度上呈显著相关且滞后0.51 a,说明AO变化对北疆气温和降水具有实际预报价值。
Increasing of temperature and precipitation has affected the ecosystem and development of agriculture and animal husbandry in north Xinjiang in recent years,thus it is necessary to analyze climate change and its attribution. Based on the monthly data of temperature and precipitation at 23 meteorological stations in north Xinjiang and the standard arctic oscillation( AO) index during the period from 1965 to 2012,the changes of temperature and precipitation and their response to AO were analyzed by using the methods of linear tendency estimation,cumulative departure,correlation analysis and wavelet transform analysis. The results are as follows: 1 The annual temperature and precipitation in recent 48 years increased with rates of 0. 41 ℃ ·( 10a)~(-1)and 11. 26 mm·( 10a)~(-1).Abrupt changes of temperature and precipitation were obvious around 1988 and 1986 respectively. The temperature in spring,autumn and winter in north Xinjiang increased significantly after the abrupt changes,but its change was not evident in summer. Seasonal precipitation in north Xinjiang increased,especially in winter; 2 There was a certain similarity in the change periods of temperature,precipitation in north Xinjiang and AOI,particularly there was a good correspondence between frequency domains of temperature and precipitation in winter and summer and AOI at the scale of quasi-3-year period; 3 There was a high correlation between winter temperature series in north Xinjiang and AOI,winter temperature and precipitation in north Xinjiang and AOI at multi-time scales were significantly correlated with a time lag of 0. 5- 1 year,indicating that AO has a real value to predict temperature and precipitation in north Xinjiang.