Assimilation of high-frequency radar currents in a nested model of the West Florida Shelf

• Published in: Journal of Geophysical Research
• Main Authors: Barth, Alexander, Alvera Azcarate, Aïda, Weisberg, R. H.
• Other Authors: Centre Interfacultaire de Recherches en Océanologie - MARE - GHER
• Format: Article in Journal/Newspaper
• Language: English
• Published: American Geophysical Union (AGU) 2008
• Subjects: primitive equation model; coordinate; system; climatology; circulation; error; North Atlantic-Ocean; Sea Surface temperature; Physical; chemical; mathematical & earth Sciences; Earth sciences & physical geography; Physique; chimie; mathématiques & sciences de la terre; Sciences de la terre & géographie physique; North Atlantic
• Online Access: https://orbi.uliege.be/handle/2268/26171; https://doi.org/10.1029/2007JC004585

peer reviewed High-frequency radar currents are assimilated in a West Florida Shelf (WFS) model based on the Regional Ocean Model System (ROMS), which is nested in the Atlantic Hybrid Coordinate Ocean Model (HYCOM) for the purpose of including both local and deep-ocean forcing, particularly the Gulf of Mexico Loop Current. Tides are not included in this model. An ensemble simulation of the WFS model is carried out under different wind-forcings in order to estimate the error covariance of the model state vector and the covariance between ocean currents and winds. Radial currents measured by high-frequency radar antennas near Saint Petersburg and Venice, Florida, USA, are assimilated using this ensemble-based error covariance. Different assimilation techniques using a time-average ensemble, a filter to reduce surface-gravity waves and an extended state vector including wind stress were tested. Results of the WFS model assimilating surface currents show an improvement of the model currents not only at the surface but also at depth.