Daytime and nighttime heat wave characteristics based on multiple indices over the China-Pakistan economic corridor
Daytime and nighttime heat wave characteristics based on multiple indices over the China-Pakistan economic corridor
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基于多指标的中巴经济走廊昼夜热浪特征
DOI：
10.1007/s00382-019-04934-7
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发表时间：
2019
期刊：
影响因子：
4.6
通讯作者：
Wenxin Xie
中科院分区：
文献类型：
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作者：
Safi Ullah;Qinglong You;Waheed Ullah;Daniel Fiifi Tawia Hagan;Amjad Ali;Gohar Ali;Yuqing Zhang;Mushtaq Ahmad Jan;Asher Samuel Bhatti;Wenxin Xie
气温的急剧上升增加了世界不同地区热浪的频率、强度、持续时间和时间。受气候变化的影响，中巴经济走廊（CPEC）是HW的高度脆弱地区之一，需要对该地区的HW现象进行全面的研究。基于多指标分析了中巴经济走廊地区昼夜HW特征的时空变化。我们使用了1980-2016年48个气象站的日最高和最低气温（以下简称Tmaxand Tmin）。采用非参数修正Mann-Kendall检验、Theil-Sen检验、最小二乘法、学生t检验和卡方拟合优度检验等方法分析了白夜HW特征的长期时空变化。研究结果表明：年白天和夜间HW事件的次数、年参与白天和夜间HW的天数之和、年白天和夜间HW事件的平均长度、年最长白天和夜间HW事件的持续时间、年所有白天和夜间HW事件的平均强度、年最热白天和夜间HW事件的振幅、年末日/夜HW事件的结束日期分别以0.78/1.43、10/11.82、2/1.74、2.16/1.52 d、0.40/0.59、0.24/0.73和12.29/10 d的速率呈显著增加趋势。尽管如此，每年第一次白天和夜间高温事件的发生日期呈现出−5.71/−5天的显著下降趋势。HW行为呈明显的正向趋势，表明在研究期间，该国的HW发生频率更高、强度更强、强度更大、时间更长。趋势的空间格局表明，巴基斯坦南部、中部和东部地区HW活动突出且一致，而西北部山区HW指数空间变异性较大，部分台站HW指数呈下降趋势。这项研究的结果将成为预测和减轻该区域高温天气的基础。在此基础上，我们建议在研究区域深入研究高温天气的机制及其自然和人为驱动因素。
The sharp rise in temperature has increased the frequency, intensity, duration, and timing of heat waves (HWs) over different regions of the world. Due to climate change, the China–Pakistan Economic Corridor (CPEC) is one of the highly vulnerable regions to HWs and needs comprehensive research studies to investigate the HW phenomenon in the region. This study analyzed the spatial and temporal changes in the daytime and nighttime HW characteristics based on multiple indices over the CPEC region. We used daily maximum and minimum temperatures (hereafter Tmaxand Tmin) of 48 meteorological stations for the time period of 1980–2016. The non-parametric modified Mann–Kendall, Theil–Sen’s test, least square method, student t-test, and chi-square goodness-of-fit test techniques were used to analyze the long-term spatiotemporal changes in the daytime and nighttime HW characteristics. The results of the study show that the number of annual daytime/nighttime HW events, annual sum of participating daytime/nighttime HW days, the average length of annual daytime/nighttime HW events, duration of the longest annual daytime/nighttime HW event, the average magnitude of all annual daytime/nighttime HW events, amplitude of the hottest annual daytime/nighttime HW event, and the ending date of annual last daytime/nighttime HW event exhibited significant increasing trends at the rate of 0.78/1.43 events decade−1, 10/11.82, 2/1.74, 2.16/1.52 days decade−1, 0.40/0.59, 0.24/0.73 °C decade−1, and 12.29/10 days decade−1, respectively. Despite all, the onset date of the annual first daytime/nighttime HW event has shown a significant decreasing trend of − 5.71/− 5 days decade−1. The obvious positive trend of HW behaviors indicates that the country has experienced more frequent, stronger, more intense, and longer HWs during the study period. The spatial pattern of the trend indicates that the southern, central and eastern parts of Pakistan exhibited prominent and consistent HW activities, while the northwestern mountainous regions showed high spatial variability with some stations exhibited decreasing trends in HW indices. The findings of this study will be a base for the projection and mitigation of HWs in the region. Based on the study findings, we recommend that the mechanism of HW and its natural and anthropogenic drivers should be thoroughly investigated over the study region.