MWB 02 PROMESMOSLEF An atmosphereocean coupled regional model

MWB 02 PROMES-MOSLEF: An atmosphere-ocean coupled regional model. Coupling and preliminary results over the Mediterranean basin Clemente Gallardo Andrés, Institute of Environmental Sciences – Universidad de Castilla La Mancha, Toledo, Spain Pedro Galán del Sastre, Department of Applied Mathematics (ETSAM) – Universidad Politécnica de Madrid, Spain Rodolfo Bermejo, Department of Applied Mathematics (ETSII) – Universidad Politécnica de Madrid, Spain ABSTRACT Over the last year, in the frame of the Spanish project MERCATOP, the regional atmospheric climate model PROMES and the finite elements semi-Lagrangian ocean model MOSLEF have been integrated in a unique system named PROMES-MOSLEF. OASIS 3 coupler has been used as grid interpolator, inter-model communicator and interlanguage communicator to link these two models. Currently, the system can be run in four different modes: atmosphere mode, ocean mode with climatological atmospheric feeding, ocean mode with regional modelling atmospheric feeding, and atmosphere-ocean coupled mode. Following Med. Cordex specifications, the first simulations using the system PROMES-MOSLEF have been focussed in the Mediterranean basin and the ERA-Interim period. In this work preliminary results obtained by using the system are shown and a comparison of those simulations is also presented. COUPLING PROMES The system can be run in four different modes: 1. atmosphere 2. ocean with climatological atmospheric forcing 3. ocean with ARCM forcing, and 4. atmosphere-ocean full coupled Recent Improvements in the regional atmospheric model PROMES: • ECMWF-based Radiation E C A F R E T N I INT ERF ACE OASIS-3 • ORCHIDEE land surface model Interactive phenology Dynamic vegetation River routing Oasis 3 has been used in our coupled model as: • Grid interpolator • Inter-model communicator • Inter-language communicator Communication technique: CLIM/MPI 1 MOSLEF Semi-Lagrangian Finite Element Ocean Model Primite Equations of the Ocean Time Discretization • Implicit scheme for diffusion terms • Semi-Lagrangian approach for advection terms • Splitting scheme to decouple velocity and pressure Unconditional stable scheme Δt = 1 h 30 min Spatial Discretization Finite Element Method PROMES uses OASIS Box partition type. • Unstructured meshes • Easy definition of the boundary • Easy refinement in regions MOSLEF currently uses a Serial partition type MOSLEF (MODE 2) WINTER VELOCITY PRELIMINARY RESULTS MOSLEF (MODE 2) SUMMER VELOCITY Several preliminary simulations have been run in order to test the proper working of the system. Here some results of two simulations of the ocean model MOSLEF in the mode 2 of the system (atmospheric forcing provided by climatology) and the mode 3 (atmospheric forcing provided by PROMES, but MOSLEF running offline) are shown MOSLEF (MODE 3) WINTER VELOCITY In the pictures a correct performance of MOSLEF can be seen. Both in summer and winter the model results have a reasonably good approximation to the main characterictics of the Mediterranean Sea surface circulation (see Roussenov et al. , 1997 and its references). MOSLEF (MODE 3) SUMMER VELOCITY Mode 2 and mode 3 of the system give lightly different results, mainly in the strength of some vortex. This is an expected result because of the larger variability of the ARCM atmospheric forcings. REFERENCES Roussenov, V. , E. Stanev, V. Artale and N. Pinardi (1995) A seasonal model of the Mediterranean Sea general circulation. J. Geophys. Res. , 100 (C 7): 13515 -13538. Dorado, E. (2009) Estudio de soluciones numéricas de largo plazo de los modelos de ecuaciones primitivas de la circulación general del océano. Ph. D thesis, Universidad Complutense de Madrid. Castro M, Fernandez C, Gaertner MA (1993) Description of a meso-scale atmospheric numerical model. In: Diaz JI, Lions JL (eds) Mathematics, climate and environment, Masson (ISBN: 2 -225 -84297 -3), p 273. Valcke, S. (2006) OASIS 3 User Guide (oasis 3_prism_2 -5) PRISM Support Initiative Report No 3. CERFACS, Toulouse, France. 64 pp. ACKNOWLEDGMENTS This work has been funded through the Spanish projects CGL 2007 -66440 -C 04 -01 and CGL 200766440 -C 04 -02 of the Education and Science Ministry of Spain