Analysis of Trends in the Variability of Summer High Temperature Days During 1960—2008 in Beijing,Tianjin and Hebei
Based on the arranged daily maximum air temperature data from 83 stations in the Beijing-Tianjin -Hebei region（Jingjinji） during the summer of 1960-2008,the temporal and spatial distributions of summer high temperature days（SHTD,daily maximum temperature equal to or higher than 35℃） in Jingjinji are studied with a focus on the long-trends.The line trend analysis and moving t test are used in the analysis.The results show that the SHTDs in Jingjinji display a spatial distribution pattern of ＂more in the south and less in the north＂.And the high center is located near the Nangong Station in the south. The SHTDs in Jingjinji have an evolutional trend of increasing-decreasing-increasing,and do not have significant linear trends.But there exist mainly a decreasing linear trend in the south and an increasing linear trend in the north.By using the moving t test,two points of sudden change are detected,which occurred in 1972 and 1996,respectively.However,the SHTDs in the north of Jingjinji have only a change point. Compared with those during 1960-1972,more SHTDs occurred over Jingjinji during 1997-2008 and the years with more SHTDs are more centralized.The SHTDs during 1997-2008 reveal a significant decreasing trend.
summer high temperature dayslong-trendsudden change
国家科技期刊平台
NSTL
万方数据
维普
