Trends in Environmental Research Series -An overview of dynamical climate downscaling activities in CSIRO

Speaker: Dr. John McGregor CSIRO/Centre for Australian Weather and Climate Research, Australia

Title: An overview of dynamical climate downscaling activities in CSIRO

Coupled atmosphere-ocean Global Climate Models (GCMs) are increasingly being used to simulate future climate change. Because of their computational expense, the grid resolution of those GCMs is typically around 200 km, which is too coarse to directly provide detailed climate simulations, especially for regions with complex topographic or land-use features. An approach that has become fairly common, is to use regional climate models, driven in some manner by a coupled GCM, to simulate the climate at smaller length scales. Some groups use limited-area models for this purpose, driven at the lateral boundaries by a host GCM, and this approach was originally used at CSIRO with the DARLAM model. For about the last 10 years, downscaling at CSIRO has been performed instead with a variable-resolution global atmospheric model, the Conformal-Cubic Atmospheric Model (CCAM). With computational and technical advances, it is now possible to run models, such as CCAM, downscaled from a variety of host models and scenarios.
A number of simulations will be shown over the Australian region. These include 140-year simulations at 60 km and 14 km resolution, driven by sea surface temperatures (SSTs) and sea-ice distributions from the CSIRO Mk 3.5 coupled GCM, as well as from five coupled GCMs of the IPCC Fourth Assessment (AR4): GFDL2.1, GFDL2.0, HadCM2, ECHAM5 and Miroc-Medres, all for the A2 emissions scenario. This set of downscaled simulations provides an ensemble of regional climate change scenarios.

Time: 13.00 – 13.45 h
Location: CB04.05.01
Light refreshments provided after talk
All are welcome