Future Regional Climates.

Future Regional Climates by Jason Evans, John McGregor, and Kendal McGuffie, recognizes that the climate of any region depends on phenomena acting at scales ranging from global to local. Predicting future regional climates requires capturing the influence of processes across this full range of scales. While global climate models can robustly capture the large-scale effects, they are not able to resolve the regional- to local-scale effects that can significantly influence a location’s climate. In order to account for these smaller-scale processes, future global climates are ‘downscaled’ using various techniques to produce more realistic regional climates. Chapter 9 describes a number of techniques that have been used to downscale global climate simulations to the regional scale. It explores the uncertainties in the future regional climate predictions associated with the various techniques, and examines ways to quantify the ‘most likely’ future regional climate and the related uncertainty, so that informed investigations can be made into the impact on natural and anthropogenic systems of future climate change.

Figure 9.8: Mean annual rainfall for Tasmania for the period 1961e1990 from (a) the GFDL2.1 GCM, (b) the 0.5 dynamically downscaled simulation of the same GCM, (c) the 0.1 dynamically downscaled simulation of the same GCM, and (d) AWAP observations. Each resolution increase provides a better simulation of the observed sharp precipitation gradient from west to east across the island. (Adapted from Corney et al., 2010.)