Numerical experimentation with the EC-Earth system with special focus on the Mediterranean regions

Principal Investigators

Dr Wilhelm May
Danish Meteorological Institute
Lyngbyvej 100
2100 Copenhagen
Denmark

wm@dmi.dk

Project description

The aim of the special project is to tune and use a high-resolution version of the EC-Earth system for investigating climate variability and change in the Mediterranean region. Because of various kinds of teleconnections with other parts of the globe a global coupled atmosphere-ocean model has to be applied in order to properly describe the climate in the Mediterranean region. The climate in the Mediterranean region is not only linked to the tropical and the extratropical Atlantic Ocean but is also affected by the Asian summer monsoon or the El Niño/Southern Oscillation. On the other hand, the climate in the Mediterranean region is characterized by various small-scale phenomena such as small-scale cyclones. The realistic simulation of such phenomena requires a rather fine resolution of the model system.

The project applies the EC-Earth system, which is based on ECMWF’s Seasonal Forecast SYSTEM 4. It consists of the IFS atmospheric GCM and the NEMO ocean GCM, coupled by OASIS3. In the project a high-resolution version of this model system is used: the IFS atmospheric GCM at a horizontal resolution of T255 and 62 vertical levels and the NEMO ocean GCM at a horizontal resolution of about 1 degree with equatorial refinement and 31 vertical layers. This resolution is a good compromise allowing for extended climate simulations of up to 100-150 years with a rather good representation of regional details of climate.

In the beginning of the project (first half of 2009), the high-resolution version of the EC-Earth model needs be tuned in order to ensure a stable simulation of the global climate. In the further course of the project an extended simulation with constant climate forcing (second half of 2009) and an extended simulation with time-varying climate forcing (first half of 2010) will be performed. Finally, sensitivity experiments for testing some of the teleconnection mechanisms affecting the climate in the Mediterranean region may be performed (second half of 2010).

Additional information

New Project for 2009

Would accept support for 1 year only, if necessary.