High-Resolution Regional Climate Modeling and Projection of Heatwave Events over the Yangtze River Basin

Zhibo Gao,Xiaodong Yan

doi:10.3390/su14031141

Abstract

Heatwave events (HWEs) have strong impacts on human health, ecosystems, and sustainable social development. Using a gridded observation dataset and a high-resolution regional climate model (RCM), this study analyzed the characteristics of HWEs over the Yangtze River Basin (YRB) in eastern China during the historical period and projected the changes in HWEs over the YRB in the future. The daily maximum temperature (Tmax), long-lived (≥6 days) HWEs, and total (≥3 days) HWEs in the YRB all showed an obvious upward trend from 1981 to 2018, while the increase in short-lived (≥3 days and <6 days) HWEs was relatively moderate overall. The RCM of the Weather Research and Forecasting (WRF) model can simulate the characteristics of Tmax and HWEs in the historical period very well, and the projection results showed that Tmax, total HWEs, and long-lived HWEs will all increase obviously in both the SSP245 and SSP585 scenarios. Short-lived HWEs will also increase rapidly under SSP585, but they will rise slowly overall under SSP245. The changes in HWEs had distinct regional differences, and the intensity and coverage area of HWEs were greater under SSP585 overall. In the future, the increase in HWEs over the YRB region is likely to be associated with the enhancement of the western-Pacific subtropical high (WPSH) and South-Asian high (SAH), and this enhancement was also greater under SSP585. The results from the high-resolution simulation of the RCM can provide an important reference for disaster prevention and mitigation in the future.

Highlights

Received: 28 December 2021The Intergovernmental Panel on Climate Change (IPCC) in its 6th Assessment Report (AR6) reported that the global mean surface temperature in the first two decades of the 21st century (2001–2020) was 0.99 ◦ C higher than in 1850–1900 [1]
It is worth mentioning that the Yangtze River Basin (YRB) experienced persistent Heatwave events (HWEs) in 2013, and the Tmax of many weather stations set a new record
It should be mentioned that the number of long-lived HWEs increased obviously during the study period, which is the main reason for the increase in the total number of HWEs (Figure 2d)

Summary

Introduction

Received: 28 December 2021The Intergovernmental Panel on Climate Change (IPCC) in its 6th Assessment Report (AR6) reported that the global mean surface temperature in the first two decades of the 21st century (2001–2020) was 0.99 ◦ C higher than in 1850–1900 [1]. Under the background of global warming, the occurrence of extreme weather and climate events, such as heatwave events (HWE), have increased significantly, which has led to a large impact on the social economy, natural ecosystems, and human health [2,3,4,5]. HWEs persisted in the Yangtze River Basin (YRB) of eastern China during summer 2013, resulting in persistent drought that affected over nine provinces with a population of more than half a billion [5,8]. The results of a number of numerical simulations suggest that HWEs in eastern China will still increase significantly in the future in the context of global warming [5,9,10]. Most global climate models (GCMs), with resolutions from 100 km to 200 km, are generally good in capturing large-scale circulation [12,13,14], but they are not efficient enough to represent the fine-scale processes of the atmosphere, as well as Accepted: 17 January 2022

Methods

Results

Discussion

Conclusion