Regional Climate Change Projections for South-east Australia: the importance of regional atmospheric composition .

The climate of South-east Australia has been simulated using the Weather Research and Forecasting (WRF) model. WRF was implemented using a 10km horizontal grid and integrated for 25 years from 1985 through 2009 nested inside the NCEP/NCAR reanalysis. The model was extensively evaluated against observations and found to capture the climate well including the recent drought and the influence of large scale climate modes such as ENSO. WRF was then nested inside the CSIRO MK3.5 Global Climate Model and integrated for the same recent period and the last 25 years of the 21st century using the SRES A2 emission scenario. WRF was integrated using present day atmospheric composition, thus indicating the impact of the local increase in greenhouse gases. Results from this regional climate change projection are presented here and include an overall increase in near surface temperature of ~2°C and a change in precipitation of -4.2mm per year though this increase occurs almost entirely in Autumn while all other seasons experience decreasing precipitation.