阿勒泰地区近47年夏季平均最高气温及高温日数变化特征

利用阿勒泰地区7个站1961-2007年共47 a的逐日最高气温资料,采用趋势分析、Mann-Kendall突变分析、小波变换、R/S分析等方法,分析了阿勒泰地区近47 a夏季平均最高气温的变化特征。结果表明：近47 a阿勒泰地区夏季平均最高气温在波动中整体呈上升趋势,20世纪80年代中后期开始上升,90年代中期后升温趋势明显;夏季平均最高气温未发生突变;存在着18、12、8、5 a的年际变化周期;其未来变化趋势同过去一致,仍呈上升趋势。≥30℃高温日数的变化趋势与夏季平均最高气温一致,且也未发生突变,而≥35℃高温日数的变化趋势与前两项则不同,在20世纪60年代中期前呈上升趋势,60年代中期至80年代中期呈下降趋势,80年代中期至21世纪初为上升趋势,进入21世纪后又呈下降趋势。≥35℃高温日数在1974前后发生了突变。

Characteristies of Maximum Temperature and High Temperature days in summer in Aletai in Past 47 years

The variation characteristics of average maximum temperature were analyzed with thelinear trend method, Mann-Kendall test , the wavelet translation method and R/S method , based onthe daily maximum temperature in Ahay region from 196l to 2007. The results indicate that theaverage maximum temperatures in summer in the whole area showed a decrease trend in 1980swhich is not obvious sudden change. Its oscillation period was 24 a, 15 a, l0 a and 4 a.the averagemaximum temperature in summer showed increasing tendency in the past 47 years,H values weregreater than 0.5,so the extreme minimum temperature had persistence,which would be anincreasing tendency in the future. The trend in the numbers of days with maximum temperatureabove 30 ℃ was accrord with the average maximum temperatures but the trend in the numbers ofdays with maximum temperature above 35 ~C showed a decrease in 1960s and 1980s and after1980s showed an increase trend; the numbers of days with maximum temperature above 35 ℃ showed an abrupt change point in 1974 .