Intensification of the Daily Wet Day Rainfall DistributionAcross Australia

Abstract

In Australia and globally, changes in the entire distribution of daily precipitation are poorlyunderstood. An analysis of spatiotemporal changes in the intensity and frequency of wet and all dayAustralian rainfall between 1958–1985 and 1986–2013 ispresented using three different gridded datasets of daily precipitation based on varying underlying station data and interpolation methods. Ouranalysis method provides a complete picture of changes in the entire distribution as well as a coherentpicture of the spatial changes across Australia. We find that the spatial pattern of changes in total rainfallis similar to the pattern of change in wet day frequency but not to change in wet day intensity.Furthermore, more grids across Australia show statistically significant increases than decreases in rainfallintensity throughout the wet day distribution. This means that when it rains (i.e., limited to the wet daydistribution), whether it is light, moderate, or extreme rainfall, it rains more.

Publication
GeophysicalResearch Letters, 45, 8568–8576
Date