An atlas of surface fluxes based on the ECMWF re-analysis - a climatological dataset to force global ocean general circulation models

A climatological dataset for forcing global ocean models has been derived from the Re-Analysis (ERA) of the European Centre for Medium-Range Weather Forecasts. This dataset has been constructed for an ocean model intercomparison project (OMIP), in which the Max-Planck-Institute for Meteorology (MPI), the German Climate Computing Center in Hamburg, and the Alfred Wegener Institute Foundation for Polar and Marine Research in Bremerhaven were involved. The dataset is referred to as ''OMIP-Forcing''. In OMIP, the focus was on the intercomparison of the mean global circulation simulated by different ocean models. Therefore, a mean annual cycle has been produced from the 15 years of ERA by using Gaussian filtering with daily fluctuations superimposed. The precipitation and evaporation over the continents have been transformed into runoff. A scheme has been used which is based on the main drainage basins as well as the catchment areas and annual runoff observations of the 35 largest rivers. The scheme is run independently of the ocean models. The budgets of the heat and the fresh water fluxes have been closed by modifying the bulk formulae. All three forecast cycles of ERA have been examined with respect to the demands for the closure procedure. The 24 hour cycle has the best properties. Therefore, this cycle has been chosen to be the base of the OMIP-Forcing. The dataset is compared to six other climatologies: the direct output of ERA, the Re-Analysis of the national center for environmental prediction and the national center for atmospheric research (NCEP/NCAR), the comprehensive ocean atmosphere data sets (COADS) in three different versions (Oberhuber, da Silva, and the Southampton Oceanographic Centre), and the output of the atmospheric model ECHAM4 of the MPI. (orig.)Available from TIB Hannover: RR 1347(323) / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekSIGLEDEGerman