近40 a来西安市区与郊县气温变化特征对比

Comparative Analysis on Temperature Changes in City and Suburbs of Xi'an over the Past 40 Years

利用西安市区及郊县国家级一般气象站1971年12月至2011年11月的年、季、年代平均气温作为研究对象,采用一元回归线性拟合、距平分析、变异系数、冷(暖)冬期、突变检验等分析方法,分析总结近40 a来市区及郊县的气温变化特征:(1)市区及郊县的逐年平均气温均呈上升趋势,且市区增温速率高于郊县0.27℃/10 a;(2)市区逐年极端最高气温基本持平,逐年极端最低气温明显升高;(3)市区及郊县1990年代前升温缓慢,1990年代后升温迅速;(4)市区和郊县的年平均气温升高主要来自春季和冬季升温的贡献;(5)市区及郊县冷冬基本都出现在1980年代中期之前,暖冬均出现在1990年代末以后,且市区冬季气温距平上升率高于郊县;(6)郊县的突变时间早于市区。

Based on the annual, seasonal and decadal mean temperature data at 7 meteorological stations located in city and suburban counties of Xi＇ an from December 1971 to November 2011, the variation characteristics of temperature of city and suburb over the past 40 years were analyzed by using linear regression, anomaly analysis, variable coefficients and the Mann - Kendall test. The results are as follows ： 1 ） The annual average temperature of city and suburbs in Xi＇ an showed increase trends over the past 40 years, and the rate of temperature increase in city was 0.27 ℃/10 a, which was higher than that of the entire suburban counties. 2）The annual extreme minimum temperature of city increased significantly over the past the years. The annual extreme maximum temperature of city increased a little too, but with no obvious trend. 3 ）The temperature of city and suburban counties increased slowly before the 1990s, then rose up rapidly after that. 4）The temperature rising in spring and winter brought out the annual mean temperature increase in city and sub- urban counties of Xi＇ an, and the urbanization influenced temperature of spring most in four seasons. 5 ） Colder winters appeared mostly before the mid - 1980s while the warm winters occurred after the late 1990s in city and suburban counties of Xi＇ an, and the rising rate of temperature anomaly in city was higher than that in suburban counties in winter. 6） The mutation of temperature in suburbs was earli- er than that in city.