Global Changes of seasonal extremes and means from precipitation daily climate model data

Description
We investigate simulated changes of seasonal precipitation max- ima and means in a future, warmer, climate. We use data from the ESSENCE project, in which a 17-member ensemble of climate change simulations in response to the SRES A1b scenario has been carried out using the ECHAM5/MPI-OM climate model. The large size of the dataset gives the opportunity to detect with high statistical confidence the variability of climate extremes and means. Daily precipitation data are used to calculate the seasonal precipitation maximum and the sea- sonal mean. The data are split into six time periods of 25 years to get independent time series. The seasonal peaks are modelled by using the Generalized Extreme Values (GEV) distribution, while empirical distributions are used to study changes of the seasonal precipitation mean. Finally, we use an empirical method to detect changes of ocuur- rence of very wet and dry seasons. Results indicate that over most of the world precipitation maxima are increasing in the future. Seasonal means behave differently. In many regions they are decreasing or not increasing. The occurrence of very wet seasons is strongly increasing during boreal winter in the extratropics and decreasing in the tropics.
Organised by Josette Imme