中文摘要：

利用西北地区136个气象台站1960—2004年逐月0 cm地表温度资料,采用主成分、旋转主成分和小波等分析方法,研究了西北地区年平均地表温度的时空变化特征。结果表明,近45年来西北地区年平均地表温度表现为明显的升高趋势,且升温的空间分布较为复杂,高温区和低温区交错分布,陕西、甘肃、新疆东北部和新疆南部为高温区,青海和新疆北部为低温区。经验正交分解结果表明,西北地区年平均地表温度第1特征向量表现了西北全区地温一致偏高或偏低的变化特征,第2和第3特征向量分别表现出东西及中部与东、西部相反的差异。旋转经验正交分解后发现,地表温度存在5个空间异常区,即西北东部、西北北部、西北中部、新疆南部和新疆中部,其中西北东部区、西北中部区和新疆中部区表现为高—低—高的过程,西北北部区和新疆南部区则为一致的增加趋势。各异常区年平均地表温度均存在8-16年或16-32年的长周期,西北北部区还存在4-8年的短周期。

英文摘要：

On basis of the monthly surface temperature data collected from 136 observational stations in Northwest China（ NWC） during 1960-2004,the methods of principal component analysis,rotated principal component analysis and wavelet analysis were used to analyze the spatial and temporal characteristics of annual mean surface temperature in NWC. The results showed that the annual mean surface temperature in NWC in the past 45 years was obviously increasing,and the spatial distribution of the warming was more complicated. High temperature zone and low temperature area staggered distribution,the annual mean surface temperature decreased in Shanxi,Gansu and northeast and south of Xinjiang and increased in Qinghai and north of Xinjiang. The empirical results showed that the first eigenvector showed the consistent high or low of annual mean surface temperature in entire NWC,and the second eigenvectors showed the annual mean surface temperature in eastern NWC are opposite with western NWC,vice versa; the third eigenvectors showed the annual mean surface temperature in mid NWC were opposite with eastern and western NWC,respectively. Rotational experience orthogonal decomposition revealed that the surface temperature abnormal area could be divided into fifth sub regions： eastern NWC,northern NWC,mid NWC,southern Xinjiang and mid Xinjiang. The eastern NWC,mid NWC and mid Xinjiang showed high-low-high process,northern NWC and southern Xinjiang were the same increase trend. All the sub regions exist 8 - 16 years or 16 - 32 years periodic oscillations,only the northern NWC exist 4 - 8 years periodic oscillation.