1979~2019年我国西南地区高温热浪时空分布特征研究

Study on Spatiotemporal Distribution Characteristics of High Temperature and Heat Waves in Southwest China from 1979 to 2019

在全球变暖的大背景下,极端暖事件发生越来越频繁。为了进一步研究西南地区高温热浪时空分布特征规律,利用欧洲中期天气预报中心(ECMWF)的1979至2019年夏季的温度数据资料,运用趋势分析和Mann-Kendall检验等气候诊断方法,对西南地区高温热浪的时空分布特征进行研究,结果表明:41年来,高温热浪频次、持续时间和强度均在总体上呈现出线性增加的趋势,其速率分别为0.09次/10a、0.37 d/10a、0.44℃∙d。从突变情况看,2013年以前,高温热浪频次、持续时间和强度表现出增加趋势,但增加趋势不显著;2013年以后,高温热浪频次、持续时间和强度呈现出显著增加趋势;高温热浪频次、持续时间和强度在空间上的分布大致呈现东南多西北少的特征。高温热浪多发地区集中在研究区域中东部,而四川西部、云南西南部很少发生高温热浪事件;研究区域高温热浪频次、持续时间和强度除了云南西部和四川西部呈减少或不变趋势,其他地区都呈增加趋势,研究区域的中部地区增加趋势更大,通过0.05显著性检验的区域也集中在中部。

In the context of global warming, extreme warming events occur frequently. In order to further study the spatial and temporal distribution characteristics of heat wave in southwest China, in this paper, linear trend analysis and Mann-Kendall test are used to study the spatial and temporal distribution of heat waves in southwest China. The 1979-2019 summer temperature data of European Centre for Medium-Range Weather Forecasts (ECMWF) are used. The following conclusions are drawn: Over the past 41 years, the frequency, duration and intensity of heat waves have shown a general trend of linear increase, with the rates of 0.09 times/10a, 0.37 d/10a and 0.44˚C∙d, respectively. From the mutation situation, before 2013, the frequency, duration and intensity of heat waves showed an increasing trend, but the increasing trend was not significant. After 2013, the frequency, duration and intensity of heat waves showed a significant increase trend. The spatial distribution of the frequency, duration and intensity of heat waves is more in the southeast and less in the northwest. The heat waves areas were concentrated in the central and eastern part of the study area, while the hot and heat wave events were rare in western Sichuan and southwestern Yunnan. Except for western Yunnan and western Sichuan, the frequency, duration and intensity of heat waves in the study area all showed an increasing trend. The central region of the study area had a larger increasing trend, and the regions that passed the 0.05 significance test were also concentrated in the central region.