Model intercomparison in the Mediterranean: MEDMEX simulations of the seasonal cycle

in Journal of Marine Systems (2002), 33

The simulation of the seasonal cycle in the Mediterranean by several primitive equation models is presented. All models were forced with the same atmospheric data, which consists in either a monthly ... [more ▼]

The simulation of the seasonal cycle in the Mediterranean by several primitive equation models is presented. All models were forced with the same atmospheric data, which consists in either a monthly averaged wind-stress with sea surface relaxation towards monthly mean sea surface temperature and salinity fields, or by daily variable European Centre for Medium Range Weather Forecast (ECMWF) reanalysed wind-stress and heat fluxes. In both situations models used the same grid resolution. Results of the modelling show that the model behaviour is similar when the most sensitive parameter, vertical diffusion, is calibrated properly. It is shown that an unrealistic climatic drift must be expected when using monthly averaged forcing functions. When using daily forcings, drifts are modified and more variability observed, but when performing an EOF analysis of the sea surface temperature, it is shown that the basic cycle, represented similarly by the models, consists of the seasonal cycle which accounts for more than 90% of its variability. (C) 2002 Elsevier Science B.V. All rights reserved. [less ▲]

Soft project: a new ocean forecasting system based on satellite data

Conference (2002)

The aim of the SOFT project is to develop a new ocean forecasting system by using a combination of satellite data, evolutionary programming and numerical ocean models. To achieve this objective two steps ... [more ▼]

The aim of the SOFT project is to develop a new ocean forecasting system by using a combination of satellite data, evolutionary programming and numerical ocean models. To achieve this objective two steps are proposed: (1) to obtain an accurate ocean forecasting system using genetic algorithms based on satellite data; and (2) to integrate the above new system into existing deterministic numerical models. Evolutionary programming will be employed to build "intelligent" systems that, learning from the past ocean variability (provided by satellite data) and considering the present ocean state, will be able to infer near future ocean conditions. Validation of the forecast skill will be carried out by comparing the forecasts fields with satellite and in situ observations. Validation with satellite observations will provide the expected errors in the forecasting system. Validation with in situ data will indicate the capabilities of the satellite based forecast information to improve the performance of the numerical ocean models. This later validation will be accomplished considering in situ measurements in a specific oceanographic area at two different periods of time. The first set of observations will be employed to feed the hybrid systems while the second set will be used to validate the hybrid and traditional numerical model results. Keywords: forecasting, satellite data, empirical orthogonal functions, numerical models, genetic algorithms, neural networks, Mediterranean Sea. [less ▲]

Progress from 1989 to 1992 in understanding the circulation of the Western Mediterranean Sea

in Oceanologica Acta (1995), 18(2), 255-271

The present paper describes the major results obtained from 1989 to 1992 by the EUROMODEL group in studying the circulation in the Western Mediterranean Sea. Particular emphasis has been given to the ... [more ▼]

The present paper describes the major results obtained from 1989 to 1992 by the EUROMODEL group in studying the circulation in the Western Mediterranean Sea. Particular emphasis has been given to the physical processes responsible for seasonal and mesoscale variabilities. Observations (in situ and satellite), together with theoretical, physical and numerical models, have been widely used in the course of these studies. Attention has been focused on the dynamics of the northern basin (deep water formation, dynamics of the Northern Mediterranean Current, circulation and shelf/slope interaction in the Balearic Sea) and of the southern basin (Alboran Sea circulation, instabilities of the Algerian Current). The straits dynamics have been studied with particular reference to the Corsica channel. Preliminary runs of a basin-scale circulation model of the Western Mediterranean Sea forced by the straits are also presented. They are shown to be capable of generating a cyclonic circulation in the western basin. [less ▲]

Topographic forcing of the circulation of LIW in the Western Mediterranean

in Coastal Estuarine Studies (1994), 46

Circulation of the Western Mediterranean has been inferred from tracer properties and is the object of numerical modelling studies (eg., Beckers, 1991). The path of the Levantine Intermediate Water (LIW ... [more ▼]

Circulation of the Western Mediterranean has been inferred from tracer properties and is the object of numerical modelling studies (eg., Beckers, 1991). The path of the Levantine Intermediate Water (LIW), thought o be a buoyancy forced flow, provides an indicator of mid-depth circulation (Millot, 1987b). However, modelling studies which include buoyancy forcing appear to misrepresent the flow of LIW. We have used the 'GFDL Modular Ocean Model' (MOM) to explore the suggestion of Holloway (1992) that subgridscale eddy-topography interaction may be responsible for such systematic defects. We have executed MOM with and without the parametrization of the eddytopography interaction. The different results are compared with circulation inferred from observational data. [less ▲]