近56年安徽省极端气温变化及其与气候指数的关系

为了研究安徽地区对全球变暖的响应,基于1960-2016年安徽省78个气象站的月值极端气温数据,采用数理统计和GIS空间分析方法,研究多时间尺度下的极端气温时空变化特征,并探讨了极端气温与气候指数的相互关系。结果表明:(1)近56 a安徽省年极端最高、最低气温总体上均呈现上升趋势,极端最低气温的增温幅度(0.37℃/10 a)大于极端最高气温(0.12℃/10 a);(2)年极端最高气温的突变时间为2001年,比极端最低气温(1986年)晚了15 a。年极端最高、最低气温的Hurst指数都大于0.5,存在显著的Hurst现象,持续以往的升温趋势;(3)极端气温区域平均值总体呈上升趋势,但在不同地区气温变化的幅度和趋势存在一定差异;(4)极端气温与3个气候指数存在着多时间尺度的相关性,极端最高气温与ENSO,PDO,AO分别存在2.5~6 a,3~6 a,7.5~11 a的共振周期。极端最低气温与ENSO,PDO,AO分别在3~6 a,4.5~5.5 a,1~3.5 a的时间尺度上有着强凝聚性共振周期。总之,研究期间安徽省极端最低温度的上升对整个区域的变暖趋势起着重要作用,极端温度与3个气候指标具有多时间尺度遥相关现象。

Variation of Extreme Temperature and Its Association with Climate Indices in Anhui Province During the Past 56 Years

The primary objective of this study is to investigate the response of Anhui Province to global warming.Based on month temperature data from 78 stations in Anhui Province,the long term daily temperatures observed during the period from 1960 to 2016 were analyzed,and the spatial and temporal variation characteristics of extreme maximum and minimum temperature were depicted by using the mathematic statistic methods and GIS spatial analysis.The relationship between the extreme temperature and ENSO,PDO and AO were also analyzed by using the cross wavelet and wavelet coherence techniques.The results showed that:(1)The annual extreme maximum and minimum temperature in Anhui Province had been rising over the study period trend.The linear increasing rate of annual extreme minimum temperature(0.37℃/decade)was obviously higher than that of annual extreme maximum temperature(0.12℃/decade).(2)The abrupt change of annual extreme maximum temperature occurred about 15 years later than the extreme minimum temperature abrupt changes(in 2001 and 1986,respectively).Asymmetric changes were observed in the annual extreme maximum and minimum temperature.There was obvious Hurst phenomenon in the future,which showed that the trendy ingredients were existed in Anhui Province during recent 56 years.(3)The spatial and temporal variation distribution of average extreme temperature showed the regional differences in the area,even though the overall change of regional extreme temperature was rising nearly 56 years,yet the temperature in different areas had differences in trend and range.(4)The relationship between the extreme temperature and the three large-climate indices presented significant periodic variations.The in-phase relations between extreme maximum temperature and ENSO,PDO,AO were found in almost all the time-frequency domains,good coherence could be found in the circle of 2.5 to 6 years,3 to 6 years and 7.5 to 11 years,respectively.The impact of climate indices on extreme minimum temperature mainly occurred in the circle of 3 to 6 years,4.5 to 5.5 years and 1 to 3.5 years.The rise of extreme minimum temperature played the major role in the warming trend of the whole region,and the extreme temperature and three climate indices had a multi time scale teleconnection phenomenon.