Impact of atmospheric circulation on the rainfall-temperature relationship in Australia

Bhavik Magan (1) , Seokhyeon Kim (1) , Conrad Wasko (2) , Renaud Barbero (3) , Vincent Moron (4) , Rory Nathan (2) , Ashish Sharma (1)

1 UNSW - University of New South Wales [Sydney]
2 University of Melbourne
3 RECOVER - Risques, Ecosystèmes, Vulnérabilité, Environnement, Résilience
4 CEREGE - Centre européen de recherche et d'enseignement des géosciences de l'environnement

Anthropogenic climate change is leading to the intensification of extreme rainfall due to an increase in atmospheric water holding capacity at higher temperatures as governed by the Clausius-Clapeyron (C-C) relationship. However, the rainfall-temperature sensitivity (termed scaling) often deviates from the CC relationship. This manuscript uses classifications prescribed by regional-scale atmospheric circulation patterns to investigate whether deviations from the CC relationship in tropical Australia can be explained by differing weather types (WT). We show that the rainfall-temperature scaling differs depending on the WTs, with the difference increasing with rainfall magnitude. All monsoonal WTs have similar scaling, in excess of the CC relationship, while trade winds (the driest WTs) result in the greatest scaling, up to twice that of the CC relationship. Finally, we show the scaling for each WT also varies spatially, illustrating that both local factors and the WT will contribute to the behaviour of rainfall under warming.

Mots clés: rainfall-temperature scaling; weather types; climate change; ZABR

Domaines: Milieux et Changements globaux; Océan, Atmosphère

Bhavik Magan, Seokhyeon Kim, Conrad Wasko, Renaud Barbero, Vincent Moron, et al.. Impact of atmospheric circulation on the rainfall-temperature relationship in Australia. Environmental Research Letters, 2020, pp.1-12. ⟨10.1088/1748-9326/abab35⟩. ⟨hal-02962639⟩