No significant difference between Australian heat wave impacts of Modoki and eastern Pacific El Niño

Abstract

The influence of two El Niño types on the frequency of summer heat wave days in Australia is investigated using both observations and an atmospheric climate model. The two basic spatial variants of El Niño are the traditional warming in the eastern equatorial Pacific (EP) and the Modoki variant that has its largest warming in the central equatorial Pacific. While impacts of Modoki El Niño on Australian precipitation can be quite distinct from EP El Niño, the impact on heat waves is still unknown. Using a set of ensemble simulations, we compare the influence of Modoki and EP sea surface temperature forcing on Australian heat waves. We find that there is minimal difference between the impact of Modoki and EP El Niños on heat waves over Australia, which implies that future studies on heat wave variability need not differentiate the two.