乌鲁木齐地温特征及其与降水的关系

Characteristics of Ground Temperature and its Relation with Precipitation in Urumqi

基于乌鲁木齐1961—2008年地温和降水资料,使用一元线性回归、Mann-Kendall突变检验、相关等统计方法,分析了地温的时间变化特征及其与夏季降水的关系。结果表明:浅层地温(0 cm和40 cm)的季节变化与大陆气温一致,而80 cm和160 cm,则与海温一致,320 cm地温表现为准半年的变化特征。各层年均地温有较一致的年际变化,1990年至今,均处在高值期。40 cm和80 cm的年均地温呈下降趋势,而160 cm和320 cm为上升趋势。在冬季,各层地温均呈显著的升温趋势,且均在2000年后发生了由低到高的气候突变。相关分析发现,320 cm前一年12月的地温与当年夏季降水相关性较好,相关系数可达0.38。进一步的分析发现,前一年秋季8月和9月,160 cm与320 cm地温的梯度与当年夏季降水有较好的正相关,相关系数分别为0.41和0.4,可以作为夏季降水长期预测的一个参考因子。

Based on the ground temperature and precipitation data during 1961-2008 in Urumqi, the time variation characteristics of ground temperature and their relation with summer precipitation were analyzed with the statistical methods such as simple linear regression, Mann-Kendall abrupt test and correlation. The results showed that the monthly variation characteristics of shallow layer ground temperature was similar to the air temperature and that in deep layers was similar to sea temperature, but the temperature at 320cm presented the quasi half year variation characteristics. The annual mean ground temperature for each layer had consistency of annual variation and had been in high value period since 1990. The annual mean ground temperature at 40cm and 80era presented descending trend and that at 160cm and 320cm presented ascending trend. The ground temperature in winter for each layer had a significant ascending trend and climate abrupt occurred since 2000. The correlation analysis indicated that the ground temperature at 320cm for the December had a good correlation with the precipitation of the next summer , and the correlation coefficient was 0.38. It were found in the further analysis that the ground temperature gradient between 160cm and 320cm in the August and September had a good positive correlation with summer precipitation and the correlation coefficients were 0.41 and 0.40 respectively,which could be used as a long-range forecast factor for summertime precipitation.