Modelling the barotropic sea level in the Mediterranean Sea using data assimilation

Created March 19, 2026

Updated on May 12, 2026

approved

This paper analyses the variability of the sea level barotropic components in the Mediterranean Sea and their reproduction using a hydrodynamic model with and without data assimilation. The impact of data assimilation is considered both in reanalysis and short-forecast simulations. We used a two-dimensional finite element model paired with an ensemble Kalman filter, which assimilated hourly sea level data from 50 stations in the Mediterranean basin. The results brought about a significant improvement given by data assimilation in the reanalysis of the astronomical tide, the surge, and the barotropic total sea level, even in coastal areas and far from the assimilated stations (e.g. the southeastern Mediterranean Sea). As with the reanalysis simulations, the forecast simulations, which start from analysis states, improve, especially on the first day (37 % average error reduction) and when seiche oscillations are triggered. Since seiches are free barotropic oscillations that depend only on the initial state, their reproduction improves very effectively with data assimilation. Finally, we estimate the periods and the energy of these oscillations by means of spectral analysis, both in the Adriatic Sea, where they have been extensively studied, and in the Mediterranean Sea, where the present documentation is scarce. While the periods are well reproduced by the model even without data assimilation, their energy shows a good improvement when using it.

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Tags:
Barotropic Components
Publication - Article
Basic
Language
English
MainTitle
Modelling the barotropic sea level in the Mediterranean Sea using data assimilation
Original ids
https://doi.org/10.5194/os-19-559-2023
Type
publication
bestAccessRight
OPEN
countries
Italy
Creator/Author
Full name
  • M. Bajo, orcid: 0000-0002-5969-6386;
  • C. Ferrarin, orcid: 0000-0003-1172-1463;
  • G. Umgiesser, orcid: 0000-0001-9697-275x;
  • A. Bonometto;
  • E. Coraci
Other
Description
This paper analyses the variability of the sea level barotropic components in the Mediterranean Sea and their reproduction using a hydrodynamic model with and without data assimilation. The impact of data assimilation is considered both in reanalysis and short-forecast simulations. We used a two-dimensional finite element model paired with an ensemble Kalman filter, which assimilated hourly sea level data from 50 stations in the Mediterranean basin. The results brought about a significant improvement given by data assimilation in the reanalysis of the astronomical tide, the surge, and the barotropic total sea level, even in coastal areas and far from the assimilated stations (e.g. the southeastern Mediterranean Sea). As with the reanalysis simulations, the forecast simulations, which start from analysis states, improve, especially on the first day (37 % average error reduction) and when seiche oscillations are triggered. Since seiches are free barotropic oscillations that depend only on the initial state, their reproduction improves very effectively with data assimilation. Finally, we estimate the periods and the energy of these oscillations by means of spectral analysis, both in the Adriatic Sea, where they have been extensively studied, and in the Mediterranean Sea, where the present documentation is scarce. While the periods are well reproduced by the model even without data assimilation, their energy shows a good improvement when using it.
Publication Date
2023-05-10
Publisher
Copernicus GmbH
Subjects
  • Environmental sciences;
  • 13. Climate action;
  • Geography. Anthropology. Recreation;
  • Sea level, Mediterranean Sea, SHYFEM model, data assimilation;
  • 14. Life underwater;
  • 01 natural sciences;
  • 0105 earth and related environmental sciences
isGreen
false
isInDiamondJournal
false
Software
Publication
Ending page
579
Name
Ocean Science
Publication
Article
Starting page
559
iss
3
issnOnline
1812-0792
vol
19
Other Research Product
Detailed informations
system:type
Research Product
Management Info
Author
Catalogue Manager ITINERIS
Version
1
Last Updated
May 12, 2026, 10:10 (UTC)
Created
March 19, 2026, 00:32 (UTC)
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