陕西省气温和降水时空变化特征

利用陕西省1960-2013年气象资料,分析了气温和降水时空变化特征。结果表明:(1)在时间尺度上,陕西省的年平均气温的上升速率约为0.23℃/10 a,1990年代后期以来,气温显著升高。四季气温也呈上升趋势,其中春、冬季上升速率较大。年降水量以8.78 mm/10 a的速率下降,1980年代后期以来,降水量明显减少。春、秋季降水量呈下降趋势,夏、冬季呈上升趋势。年平均气温在1996年发生突变,1996年以来为高温期,年降水量在1970年和1975年发生突变,1970年以来为相对少雨期。在10年尺度上,陕西省气候依次经历了冷湿—冷干—冷湿—暖干—暖干的变化过程,暖干化趋势明显。(2)在空间尺度上,年平均气温由南向北递减,呈现出明显的纬度地带性特征。年降水量整体由南向北递减,部分山地形成地形雨。(3)北半球中高纬度的环流系统的变化和ENSO事件是影响陕西省气候变化的重要因素。

Analysis on Spatial and Temporal Variation Characteristics of Temperature and Precipitation in Shaanxi Province

Using the meteorological data from 1960 to 2013 in Shaanxi Province, the spatial and temporal variation characteristics of temperature and precipitation has been analyzed in this paper. The results show that ： （ 1 ） On the time scale, the rising rate of the annual average temperature in Shaanxi Province was about 0.23℃/10 a and it began to rise significantly since the late 1990s. The temperature of the four seasons was also on the rise, the increased rate of spring and winter was larger. Annual precipitation was falling at a rate of 8.78 mm/10 a, precipitation was significantly lower since the late 1980s. Precipitation in spring and autumn was on the decline, in summer and winter, it was on the rise. The mutation of annual average temperature started in 1996, it became warmer since 1996. Annual precipitation mutation occurred in 1970 and 1975, precipitation was lower since 1970, in the scale of ten years, climate in Shaanxi Province has experienced the process of cold - wet, cold - dry, cold - wet, warm - dry and warm -dry, the tend of dry and warm was obvious. （2） On the spatial scale, annual average temperature was decreasing from south to north with the obvious characteristics of latitudinal zonality. Annual precipitation was decreasing from south to north and formed terrain rain in some mountains. （3） The change of the circulation system in the middle and high latitudes of the northern hemisphere and the ENSO events were important factors affected the climate change in Shaanxi Province.