Global to Regional Oceanographic Modelling
|Scientific Discipline||Physical Oceanography|
|Principal Investigator(s)||Pierre Bahurel|
|DEISA Home Site||ECMWF|
Project summary and results
The Global to Regional Oceanographic Modelling (GROM) project was realised in collaboration between two European operational oceanographic projects which are Mercator Ocean in France and ESEOO in Spain. This project is one part of the research and development activities realised during 2006 for operational oceanography. The main objectives were to build and to validate new ocean model configurations from global to regional scale able to simulate eddy permitting to eddy resolving physical processes. Several steps were defined during this project to reach the final goal which is a global eddy resolving model (1/12°) and a higher resolution (1/36°), including high frequency physical processes, regional model covering the North East Atlantic and especially the European coast from the North Africa to the south of Scandinavia. This objective is not already reached but the main components of this future system are build and the intermediate configurations based on global eddy permitting model (1/4°), eddy resolving (1/12°) North Atlantic Ocean and North East Atlantic regional model are described in the following sections.
Mean1993-2001 eddy kinetic energy for the experiment.
The DEISA Extreme computing Initiative, which has supported the GROM project, has allowed the realisation of interannual simulation of the ocean at several horizontal resolutions, over several geographic domains and with different physical processes representation. The computational cost of these ocean simulations is very high, for example one year of the NATL12 configuration used 8200 cpu hours and one year of the global ORCA12 configuration used 100 000 cpu hours on the ECMWF IBM SP4. The main results obtained with the simulations carried out during GROM project are:
- Carrying out of an interannual (1993-2006) global eddy permitting simulation, which reproduces the main features of the thermo dynamic processes in the ocean (Kuroshio, Gulf Stream, Antarctic circumpolar current, Aghulas rings, El Niño events in the pacific, monsoon seasonal cycle in the Indian ocean...) and in the sea ice.
- Carrying out of a "realistic" simulation of the North Atlantic with 1/12° horizontal resolution : The main currents of the North Atlantic (Gulf Stream, the North Atlantic current, Azores current, Greenland current...) simulated can be compared to observations in terms of position, intensity, energy.
- Carrying out of a regional model of the North East Atlantic embedded in a larger geographical model thanks to open boundaries conditions: the diagnosed eddy kinetic energy allowed us to show the positive impact of the high frequencies refreshing boundaries conditions.