Lookup NU author(s): Dr Steven Chan,
Professor Hayley Fowler,
Dr Stephen Blenkinsop
This is the authors' accepted manuscript of an article that has been published in its final definitive form by Nature Publishing Group, 2016.
For re-use rights please refer to the publisher's terms and conditions.
Extreme daily precipitation is thought to increase with temperature at a rate of 6.5% per K according to the Clausius-Clapeyron relationship between temperature and saturation vapour pressure(1). A wide range of scaling relationships has been observed globally for extreme daily and hourly precipitation, with evidence of scaling above 6.5% per K for sub-daily extreme precipitation in some regions(2-4). Only high-resolution climate models can simulate this scaling relationship(5). Here we examine the scaling of hourly extreme precipitation intensities in a future climate using experiments with a model for the southern UK with kilometre-scale resolution(6). Our model simulates the present-day scaling relationship at 6.5% per K, in agreement with observations. The simulated overall future increase in extreme precipitation follows the same relationship. However, UK extreme precipitation intensities decline at temperatures above about 22 degrees C-a temperature range that is not well sampled in the present-day integration-as a result of a more frequent occurrence of anticyclonic weather systems. Anticyclones produce more days with strong daytime heating, but are not favourable to the development of deep intense convective storms. We conclude that future extreme hourly precipitation intensities cannot simply be extrapolated from present-day temperature scaling, and demonstrate the pitfalls of using regional surface temperature as a scaling variable.
Author(s): Chan SC, Kendon EJ, Roberts NM, Fowler HJ, Blenkinsop S
Publication type: Article
Publication status: Published
Journal: Nature Geosciences
Print publication date: 01/01/2016
Online publication date: 30/11/2015
Acceptance date: 19/10/2015
Date deposited: 19/08/2016
ISSN (print): 1752-0894
ISSN (electronic): 1752-0908
Publisher: Nature Publishing Group
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