Steeper temporal distribution of rain intensity at higher temperatures within Australian storms

摘要

The mechanisms that cause changes in precipitation, as well as the resulting storm dynamics, under potential future warming remain debated(1-3). Measured sensitivities of precipitation to temperature variations in the present climate have been used to constrain model predictions(4,5), debate precipitation mechanisms(2,3) and speculate on future changes to precipitation(6) and flooding(7). Here, we analyse data sets of precipitation measurements at 6-min resolution from 79 locations throughout Australia, covering a broad range of climate zones, along with sub-daily temperature measurements of varying resolution. We investigate the relationship between temporal patterns of precipitation intensity within storm bursts and temperature variations in the present climate by calculating the scaling of the precipitation fractions within each storm burst. We find that in the present climate, a less uniform temporal pattern of precipitation-more intense peak precipitation and weaker precipitation during less intense times-is found at higher temperatures, regardless of the climatic region and season. We suggest invigorating storm dynamics could be associated with the warming temperatures expected over the course of the twenty-first century, which could lead to increases in the magnitude and frequency of short-duration floods.