http://hdl.handle.net/2122/157 Search the Channel search http://www.earth-prints.org/simple-search http://hdl.handle.net/2122/3493 Title: Daily oceanographic analyses by the Mediterranean basin scale assimilation system <br/> <br/>Authors: Dobricic, S.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Bologna, Bologna, Italia; Pinardi, N.; 2Centro Interdipartimentale di Ricerche per le Scienze Ambientali, Ravenna, Italy; Adani, M.; 2Centro Interdipartimentale di Ricerche per le Scienze Ambientali, Ravenna, Italy; Tonani, M.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Bologna, Bologna, Italia; Fratianni, C.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Bologna, Bologna, Italia; Bonazzi, A.; 2Centro Interdipartimentale di Ricerche per le Scienze Ambientali, Ravenna, Italy; Fernandez, V.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Bologna, Bologna, Italia <br/> <br/>Abstract: This study presents the upgrade of the Optimal Interpolation scheme used in the basin scale assimilation scheme of the Mediterranean Forecasting System. The modifications include a daily analysis cycle, the assimilation of ARGO float profiles, the implementation of the geostrophic balance in the background error covariance matrix and the initialisation of the analyses. A series of numerical experiments showed that each modification had a positive impact on the accuracy of the analyses: The daily cycle improved the representation of the processes with the temporal variability shorter than a week, the assimilation of ARGO floats profiles significantly improved the salinity analyses quality, the geostrophically balanced background error covariances improved the accuracy of the surface elevation analyses, and the initialisation removed the barotropic adjustment in the forecast first time steps starting from the analysis. Sun, 29 Oct 2006 22:58:59 GMT http://hdl.handle.net/2122/3492 Title: On the relationship between the water mass pathways and eddy variability in the Western Mediterranean Sea <br/> <br/>Authors: Demirov, E.; 1Department of Physics and Physical Oceanography, Memorial University of Newfoundland, St. John’s, Newfoundland, Canada.; Pinardi, N.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Bologna, Bologna, Italia <br/> <br/>Abstract: The role of mesoscales on the formation and spreading of water masses in the Western Mediterranean Sea (WMED) is studied with an ocean general circulation model (OGCM). The model is forced with inter- annually variable surface forcing for the years from 1979 to 1999. The simulations are compared with some recent observational studies of the mesoscale processes in the WMED. It is found that the model reproduces the major features of the observed mesoscale variability during the preconditioning of the deep convection in the Gulf of Lions and also the large mesoscale eddies evolution in the Algerian Basin. Thus the model is used to study the deep convection in the Gulf of Lions and the processes of spreading of deep waters after the convection period. The simulations suggest that the flow structure during the preconditioning period is dominated by the Ligurian- Provencal Current in the surface and intermediate layers, which intensifies, meanders and forms a mesoscale vortex over the Rhone fan. In the deep layers the density structures due to the old deep waters tend to organise in (deep) mesoscale cyclonic eddies. The instability of the transition zone between old and newly formed deep waters, which takes place after the violent mixing stages of the deep convection, leads to collapse of the mixed patch and formation of mesoscale eddies. Some of these eddies propagate out of the Gulf of Lions transporting deep waters into the Algerian Basin. The rest of the mesoscale eddies filled with newly formed deep waters remain in the Gulf of Lions, and tend to merge, enlarge and reorganise in an area with two or three large cyclonic eddies. After the cyclonic eddies reach the Algerian Basin they interact with the intense mesoscale field existing there. The model data together with the available satellite SLA data reveal a regular westward propagation of mesoscale eddies in the Northern Algerian Basin. This transport together with southward propagation of mesoscale eddies out of the Gulf of Lions is suggesting that the intermediate and deep waters of the WMED are transported westward by mesoscale eddies. Equivalently we can argue the intermediate and deep waters conveyor belt of the WMED is eddy driven. Sun, 29 Oct 2006 22:58:59 GMT http://hdl.handle.net/2122/2599 Title: Marine Environment and Security for the European Area (MERSEA) - Towards operational oceanography <br/> <br/>Authors: Johannessen, P. Y.; Nansen Environmental and Remote Sensing Center, and Geophysical Institute, University of Bergen, Bergen, Norway; Le Traon, I.; Institute Francais de Recherche pour l’Exploitation de la Mer, Brest, France; Robinson, K.; Southampton Oceanography Centre, University of Southampton, Southampton, United Kingdom; Nittis, K.; Hellenic Centre for Marine Research, Athens, Greece; Bell, M. J.; Met Office, Exeter, United Kingdom; Pinardi, N.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Bologna, Bologna, Italia; Bahurel, P.; MERCATOR OCEAN, Toulouse, France <br/> <br/>Abstract: An assessment of the present European operational marine monitoring and forecasting systems shows how observations, atmospheric forcing fields and ocean models combine to make useful oceanographic products possible. Sat, 29 Oct 2005 22:58:59 GMT http://hdl.handle.net/2122/2596 Title: Data assimilation of temperature and salinity profiles in the Adriatic Sea regional model <br/> <br/>Authors: Grezio, A.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Bologna, Bologna, Italia; Pinardi, N.; Università di Bologna, Corso di Scienze Ambientali <br/> <br/>Abstract: Temperature and salinity data collected during the October 2002- October 2003 period have been assimilated into a version of the Princeton Ocean Model implemented over the entire Adriatic Sea. The scheme used is SOFA (System for Ocean Analysis and Forecast, DE MEY & BENKIRAN, 2002) and this is the first coastal application of this scheme. The CTD data were collected in 4 coastal areas (Emilia – Romagna Coastal strip, the Gulf of Trieste, the Rovinj and Pelješac-Vis-Drvenik coastal strips) while temperature profiles were acquired with XBT in the southern Adriatic Sea deep ocean areas. The analysis skill scores are examined in order to evaluate the assimilation performance. The results of the assimilation are first compared with independent analyses of satellite Sea Surface Temperature (SST) and it is found that assimilation of profiles improves the SST model estimate. Furthermore, the Root Mean Square (RMS) difference between model and temperature and salinity profiles before data insertion is analysed. The range of RMS temperature error is less than 1 0C for the entire area and decreases with time, indicating a positive impact of the assimilation. The RMS of salinity is less than 1 psu and it also shows a decreasing trend during the assimilation period. Sat, 29 Oct 2005 22:58:59 GMT