Can We Model the Observed Changes in Spatial Organization of Extreme Storms at Higher Temperatures? — Australian Meteorological and Oceanographic Society

Can We Model the Observed Changes in Spatial Organization of Extreme Storms at Higher Temperatures? (#119)

Jinwan Li 1 , Conrad Wasko 1 2 , Fiona Johnson 1 , Jason P Evans 1 , Ashish Sharma 1
  1. UNSW, Kensington, NSW, Australia
  2. Department of Infrastructure Engineering, University of Melbourne, Melbourne, Victoria, Australia

An in-situ observation based study recently found decreasing storm spatial extent with increasing temperatures for 1-hr duration precipitation events in the Greater Sydney region. Here we present an assessment of a regional climate model's ability to capture this characteristics. Multiple regional climate models were considered: the first a convection-resolving simulation at 2-km resolution, the rest at a resolution of 10 km with three different convection parameterizations. Both the 2- and the 10-km resolutions that used the Betts-Miller-Janjic convective scheme simulate decreasing storm spatial extent with increasing temperatures for 1-hr duration precipitation events, consistent with the observation-based. However, other observed relationships of extreme rainfall with increasing temperature were not well represented by the models. Improved methods for considering storm organization are required to better understand potential future changes.

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