Identifying the dominant driving factors of heat waves in the North China Plain

Abstract

The driving factors of heat waves (HW) have been analyzed widely, but the relative importance of these factors is still poorly understood. In this study, the temporal and spatial variations of HW in the North China Plain (NCP) were investigated using meteorological datasets during 1961–2014. The relationship between HW and several potential driving factors related to climate change (air temperature, precipitation and solar radiation), anthropogenic activity (urbanization, irrigation and aerosol optical depth (AOD)), land-surface interaction (soil moisture, drought and land surface albedo) and atmospheric circulation were assessed. The relative importance of these factors was revealed based on all-subsets regression and hierarchical partitioning (HP) analysis. Results showed that HW in the NCP became increasingly intense, frequent, durable, and emerged earlier and terminated later, with a significant increased slope in intensity, frequency duration and timing. Spatially, greater upward trends were observed in the northern NCP. Climate warming, urbanization, irrigation, AOD, land surface albedo and Atlantic Multidecadal Oscillation were significantly correlated with HW. Based on HP analysis, the most important driving factor was climate warming, contributing approximately 40% to HW variation. The cumulative contribution rate of anthropogenic activity to the HW frequency, duration and amplitude reached nearly 35%. The AMO and land surface albedo explained approximately 15% and 20% of the HW variation, respectively. This study helps to understand the characteristics of regional extreme heat events and provides a scientific basis for developing HW alleviation strategies.