Quantifying the relationship between compound dry and hot events and El Niño–southern Oscillation (ENSO) at the global scale

Abstract

The compound dry and hot event has attracted much attention in recent decades due to their disastrous impacts on different sectors. The impact from compound dry and hot events is generally more severe than that from individual dry or hot event. Understanding the physical mechanism of this compound event is thus of particular importance for early warning to reduce potential impacts. In this study, we quantitatively assessed the relationship between the occurrence of compound dry and hot events and El Niño–Southern Oscillation (ENSO) during the warm season at the global scale. Monthly precipitation and temperature from the Climatic Research Unit (CRU) were used to estimate the occurrence of compound events, and Niño 3.4 index (NINO34) was used to represent the ENSO phenomenon. The logistic regression model was employed to model the occurrence of compound events with respect to NINO34. Results from the logistic regression model showed that ENSO played an important role in the occurrence of compound dry and hot events during the warm season in regions such as northern part of South America, southern Africa, southeastern Asia and Australia. A higher likelihood of the occurrence of compound dry and hot events in these regions was shown to be associated with higher values of NINO34 based on empirical analysis from observations. Results from this study will help improve our understanding of compound dry and hot events and aid with mitigation efforts for ameliorating their adverse impacts.