Regional Climate Simulations for Australia using the weatherathome Citizen Science Experiment

Global climate model simulations of regional climate variability and change are limited by the spatial resolution of the models that can be run with available high performance computer resources and by uncertainties in the representation of key physical processes in the models. Higher resolution climate simulations are possible using regional models nested within global models. Some of the limitations associated with the representation of physical processes can be assessed by considering the results from a number of different regional climate models.

We outline the preliminary results from a new very large ensemble of regional climate model simulations for Australia that will be produced through the weatherathome experiment. This uses the HadRM3P regional model with 50km horizontal resolution, nested within the HadAM3P global model. Simulations are run on a vast network of individual computers provided by volunteer participants, who donate free time on their personal computers. A large number of different versions of the global and regional models are used to simulate the period from 1960 to 2010 using observed changes in sea surface temperatures, sea ice, atmospheric greenhouse gases and aerosols.

Regional simulations for Europe, western US and southern Africa are already being run in the weatherathome experiment, with more than 600,000 model years of simulations completed since the launch in November 2010. Daily data for a number of surface weather variables are available from these simulations, making them well suited for assessing the impacts of climate variability and change on daily extremes.

A new region, using the Australasian CORDEX domain, has been added to weatherathome experiment and will be launched later in 2012, with beta testing already underway. Preliminary results for Australia from the global and regional model simulations run as part of weatherathome will be presented, evaluating the performance of the models in the Australian region. This evaluation includes the representation of interannual variability of temperature and rainfall, as well as the representation of daily temperature and rainfall distributions and extremes.

For more information, see http://climateprediction.net/weatherathome