Wednesday 24 August 2005

GP2
1000-1200 hours

247
Assessment of recent tidal models in the Mediterranean Sea
Arabelos, Dimitrios¹, Asteriadis, Georgios1, Contadakis, Michael¹, Papazachariou, Dimitrios¹, Spatalas, Spyridon¹
1 Department of Geodesy and Surveying, Aristotle University of Thessaloniki, Thessaloniki, Greece
Author email: arab@eng.auth.gr
Ocean tides especially in closed sea areas can deviate considerably from the theoretical values due to unequal water depths and because the continents impede the movement of water. Satellite altimetry enabled the development of improved tidal models event in closed sea areas, by assimilating altimeter data into hydrodynamical models. The Mediterranean Sea due to its morphology is an ideal test field for the assessment of tidal models, based on this technique. An attempt to assess the recent tidal models TPXO.6, GOT00.2 and NAO.99b was based on (a) an inter-comparison of tidal heights computed from the three models at different time moments on the same 15 by 15 min grid covering the Mediterranean and (b) on the comparison of the statistics of a crossover analysis of nearly 2.3 years of JASON-1 altimeter data (Cycles 1-86), before and after the tidal correction, using the three tidal models. The inter-comparison in terms of mean value and standard deviation of the differences between the tidal heights on the 15 by 15 min grid resulted in mean values ranging from 0.002 to 0.005 m and standard deviations from 0.017 to 0.031 m. However, maximum values of differences exceed several dm. On the other hand, the statistics of the crossover analysis showed a 17% decrease of the standard deviation of the JASON-1 crossover differences after the tidal correction. These results show a good agreement between the three tidal models.

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