贵阳市近70年气候突变检测及变化趋势分析

Change Point Detection of Climate in Guiyang During the Last 70 Years and Analysis of Its Change Trend

对贵州省贵阳市1951-2019年的气温、日照时数、降水量和有效降水日数进行了突变检测和变化趋势分析.结果表明:(1)贵阳市年平均气温和年平均最低气温在近70年显著上升,分别在1996和1993年发生突变,突变后气温上升尤其显著,每年分别上升0.044℃和0.056℃.年平均最高气温在研究期内显著下降,速率为每年0.008℃,没有显著突变.因此,贵阳市平均气温的上升主要受平均最低气温显著升高的影响.年平均气温日较差呈显著减小趋势,突变点在1979年.(2)年日照时数在近70年显著减少,突变点在1982年.(3)年降水量没有显著变化,但年有效降水日数显著减少.(4)年平均最高气温、年平均气温日较差与日照时数呈显著正相关,而年平均最低气温与日照时数呈显著负相关.日照时数的显著下降应是贵阳市气温变化的主因,可能是空气中气溶胶含量增加所致.

Change point detection and trend analysis were implemented for temperature, sunshine hours, precipitation and days of effective precipitation in Guiyang during the period from 1951 to 2019. The results showed that annual average temperature and annual average minimum temperature in Guiyang increased significantly during the 70 years, and the change points occurred in 1996 and 1993, respectively. The two climate factors rose at a speed of 0.044 ℃ and 0.056 ℃ per year, respectively, after the abrupt change. The annual average maximum temperature declined significantly during the entire study period at a speed of 0.008 ℃ per year, and no change point was detected. Thus, we concluded that the increase of average temperature in Guiyang was mainly influenced by the rapid rise of average minimum temperature. Annual average diurnal temperature range declined significantly with a change point in 1979. Annual sunshine hours were reduced significantly as well during the entire study period, and abrupt changes occurred in 1982. No significant change occurred for annual precipitation. However, the days of annual effective precipitation were reduced during the last 70 years. Both annual average maximum temperature and annual average diurnal temperature range were in significant positive correlations with sunshine hours, while annual average minimum temperature was negatively correlated with sunshine hours. Therefore, we inferred that the reduction of sunshine hours might be the main cause for temperature change in Guiyang, which might be resulted from the increase of aerosols in the atmosphere.