新疆博州地区近46年来的气候变化特征

根据新疆博尔塔拉蒙古自治州(简称博州,下同)四个气象代表站点的气温及降水资料,利用线性趋势函数及t检验法分析了该地区近46年的气候变化。结果表明,博州年平均气温、平均最高气温、平均最低气温均呈上升趋势,而且平均最低气温上升的幅度远大于平均最高气温的上升幅度。年平均气温及年平均最低气温约在20世纪80年代中期出现了显著的均值突变,而年平均最高气温在80年代末出现突变;除春、夏季平均最高气温无明显变化趋势外,其它各季平均气温、平均最高气温、平均最低气温均呈上升趋势,其中均以冬季增幅最大,秋季次之;80年代冬夜升温最强劲,90年代则明显减弱;夏季的平均气温与平均最低气温均在70年代中期出现突变,比其它任何突变时间都早;暖温年多发生在80年代后,冷温年多发生在20世纪60年代、70年代。年降水量略呈上升趋势,少雨年多在60年代、70年代,多雨年多在近20年,除春季外,其余各季降水略有上升趋势。

Climate change in Bortala Mongol Autonomous Prefecture, Xinjiang since recent 46 years

According to the data of temperature and precipitation at four representative meteorological stations in Bortala Mongol Autonomous Prefecture since recent 46 years,in this paper the climate change is analyzed by using the linear fitting and T-test.The results show that the mean annual,maximum and minimum temperatures in the prefecture have been in an increase trend since recent 46 years,and the increase of the mean minimum temperature is much higher than that of the maximum one.An abrupt change of the mean annual and minimum temperatures occurred in the mid-1980s,and that of the mean annual maximum temperature occurred in the late-1980s.Except the change of the mean maximum temperature in spring and summer is not so significant,the mean seasonal,maximum and minimum temperatures in other seasons are in an increase trend,especially in winter.The temperature increase at night in winter was the highest in the 1980s,but it was reduced in the 1990s.An abrupt change of the mean and minimum temperatures in summer occurred in the mid-1970s,which occurred earlier than other abrupt changes. High temperature occurred mostly after the 1980s,and the low temperature occurred mostly during the period from the 1960s to the 1970s.Annual precipitation is in a slight increase trend,it was decreased during the period from the 1960s to the 1970s,and has been increased since recent 20 years.Seasonal precipitation is increased except that in spring.