The Impacts of Climate Change on Storm Tracks in the PCMDI Suite of Models

A topic which is gaining an increasing amount of attention from the climate community is the role that synoptic-scale storms play in the current and future climate. Given the impacts of extreme weather events on the general public coupled with a growing population on a global scale, it is important to understand how synoptic-scale storm tracks change in response to global warming. We have generated storm tracks from the Program for Climate Model Diagnosis and Intercomparison (PCMDI) suite of models which are based on the IPCC 4th Assessment Report. Storm tracks are generated by applying a storm track program to six-hourly sea-level pressure (SLP) data. To gauge how the models performed for the current climate, we have generated storm track frequency and intensity climatologies from the climate of the 20th century runs for the years 1991-2000 as a baseline for the current climate. To evaluate the effects of global warming on storm tracks, we also generate storm tracks for years 2050, 2100, 2150, 2200, and 2300 from the A1B scenario of the PCMDI model suite. The year 2050 will give us a perspective on how extreme events linked to storms may change as climate change is evolving. Since CO2 is fixed at 720 PPM for the other years, a comparison of these years will test the robustness of changes in storm tracks due to global warming. Analysis of storm tracks from the PCMDI suite of models will not only provide a benchmark on the ability of climate models to reproduce extratropical cyclones in the current climate, but will also give a perspective on how storms may behave in the future.