A new assimilation tidal model for the Mediterranean Sea

D. N. Arabelos, D. Z. Papazachariou, M. E. Contadakis, S. D. Spatalas
2010 Ocean Science Discussions  
The tides for the Mediterranean Sea are described through a high resolution model (MEDI10) developed by assimilation of data into the global TPXO7.2 ocean tide model. Tidal parameters from 54 coastal tide-gauge stations around Mediterranean for eight principal constituents: M2, S2, N2, K2, K1, O1, P1 and Q1 and from 20 stations for 5 M2, S2, K1, O1 are included in the model. TOPEX/Poseidon data with all corrections applied except for the ocean tides and bathymetry from ETOPO2 were used for
more » ... were used for development of the model. The tidal parameters used in the assimilation procedure were compared with corresponding parameters extracted from the model. Comparisons were carried out with other published global or regional models. Furthermore, 10 an assessment was resulted comparing crossover differences from JASON-1 altimetry corrected for ocean tides using MEDI10 and other published global or regional models. 25 effect. These models can be used directly in altimetry applications such as ocean tide corrections. 1704 OSD Assimilation models are derived by solving the hydrodynamic equations with altimetric and tide-gauge data assimilation. The tides are constrained by the hydrodynamic equations which must satisfy the tidal fields of elevations and velocities, and the observation data from tide-gauge stations and altimetry. Generalized inverse methods allow the combination in a rational manner all of this information into tidal fields best fitting 5 both the data and the dynamics, in a least squares sense (Bennett, 1992; Egbert et al., 1994) . Basins such as the Mediterranean Sea, which are connected to the oceans through narrow entrances, have small tidal ranges (Pugh, 1987). The areas of entrances are too small for sufficient oceanic tidal energy to enter to compensate for the energy losses 10 which would be associated with large tidal amplitudes. This is the main reason of the weakness of the Mediterranean tides. Although the amplitude of the tides in the Mediterranean Sea is small, the use of the best current tidal model is very essential for many geodetic and geodynamic applications (e.g., Arabelos, 2002) . The Mediterranean Sea is divided into two large basins separated by the Sicilian 15 Channel and the Straits of Messina. The tides of the western basin are strongly influenced by the Atlantic tides which penetrate through the Straits of Gibraltar. Apart from the strait of Gibraltar, two smaller openings of the Mediterranean to the Bosporus (N-E Aegean) and the Suez (S-E Mediterranean) channels are negligible for tidal propagation studies. The Adriatic and Aegean Seas are connected to the eastern basin 20 through the Straits of Otranto and Crete, respectively. The configuration of the eastern basin is very complicated. The bathymetry of the Mediterranean Sea is quite complex with both the east and west basins being more than 4 km deep in places (see Fig. 1 ). Problems in tidal studies are due to the inadequate number of tide-gauge stations mainly along the south and east coasts of the Mediterranean and in the quality of the 25 existing data. The lack of data from deep areas is balanced by the good quality altimeter data gained e.g. from TOPEX/Poseidon and JASON-1. Existed global and regional models such as GOT00.Abstract 25 1706 Abstract OSD Abstract OSD
doi:10.5194/osd-7-1703-2010 fatcat:7drt5hc5nfa3dhivado3cnllnm