1450 / 2019-08-10 17:02:34

Different changes in dry and humid heat waves over China during 1961-2014

9、大气科学与全球变化 > 专题1：大气环流对气候的影响

In the context of climate warming, heat waves (HWs) are expected to increase in many parts of the world. However, most existing studies examine the changes in the HWs that are derived from air temperature only, possible different changes in humid HWs that consider the combined effects of relative humidity (RH) are much less understood. This study investigates the spatial and temporal changes in two different types of HWs, namely, dry and humid HWs, in China from 1961 to 2014, using daily observations at a dense network of more than 2,000 meteorological stations. Analysis results show that humid HWs occur 62% more frequently than dry HWs on average. Dry HWs are more commonly located in northern China, while humid events mainly appear in monsoonal southern regions. It is also found that all measures of both dry and humid HWs across China have been increasing during the past decades, and humid HWs have even more prominent intensifying trend than dry ones. Particularly, the national mean frequency, participating days, magnitude, and duration of dry (humid) HWs increased by 0.052 (0.195) events per decade, 0.242 (0.881) days per decade, 0.386 (0.548) ℃ per decade, and 0.087 (0.046) days per decade, respectively. These trends vary in different parts of China. The largest increment of dry HW frequency is 0.290 days per decade in the arid region of northwest China, while the fastest increment of humid HW frequency is 0.281 days perdecade. Given the additional stress induced by high humidity to extreme high temperature, we suggest that future climate change mitigation and adaption should consider the change and impacts of humid heat events.