气候变化领域集成服务门户(CCPortal): Observed heatwave changes in arid northwest China: Physical mechanism and long-term trend

CCPortal

DOI	10.1016/j.atmosres.2020.105009
	Observed heatwave changes in arid northwest China: Physical mechanism and long-term trend
	Luo M.; Ning G.; Xu F.; Wang S.; Liu Z.; Yang Y.
发表日期	2020
ISSN	0169-8095
卷号	242
英文摘要	Arid regions suffer seriously from frequent and severe heatwaves. As compared to other regions, however, the synoptic-scale characteristics and mechanism of heatwave events in arid region are less understood and warrant in-depth investigations. Using observational and reanalysis datasets, here we investigate the heatwave behaviors in arid northwest China (ANC) during 1961–2014. Results reveal that heatwaves in ANC are accompanied by a hot and dry air column. In particular, the main synoptic systems are characterized by a warm-core low pressure in the lower troposphere and a deep warm high pressure in the middle and upper troposphere over the ANC and nearby regions, resulting in the heatwaves there. In the lower troposphere, the prevailing southerly flow induced by the warm-core low pressure increases the near-surface air temperature via warm advection. In the middle and upper troposphere, the deep warm high pressure is accompanied by sinking motion over the ANC surrounding region, leading to clear-sky conditions and less precipitation. These pressure configurations facilitate temperature increases by radiative heating and subsidence warming. Notably, the deep warm high pressure is closely associated with the evolution and eastward movement of a wave-like pattern over the northern midlatitudes. Over the long-term period, the heatwave in ANC exhibits significant intensifying trends in terms of increasing frequency (0.40 events decade−1), prolonging duration (1.67 days decade−1), and strengthening amplitude (0.32 °C decade−1). Also, we find that heatwaves in ANC tend to commence earlier and end later during recent decades. These findings provide scientific evidence from the synoptic and climatic perspectives for understanding the formation mechanism and forecasting of the heatwaves in arid regions. © 2020 Elsevier B.V.
关键词	Arid regions Characteristics and mechanisms Formation mechanism Near surface air temperature Physical mechanism Scientific evidence Surrounding regions Temperature increase Upper troposphere Troposphere arid region formation mechanism heat wave high pressure system long-term change low pressure system synoptic meteorology trend analysis China
语种	英语
来源机构	Atmospheric Research
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/132444
推荐引用方式 GB/T 7714	Luo M.,Ning G.,Xu F.,et al. Observed heatwave changes in arid northwest China: Physical mechanism and long-term trend[J]. Atmospheric Research,2020,242.
APA	Luo M.,Ning G.,Xu F.,Wang S.,Liu Z.,&Yang Y..(2020).Observed heatwave changes in arid northwest China: Physical mechanism and long-term trend.,242.
MLA	Luo M.,et al."Observed heatwave changes in arid northwest China: Physical mechanism and long-term trend".242(2020).