Altimetric assimilation in a Mediterranean general circulation model.

dc.contributor.author	Δρακόπουλος, Πάνος	el
dc.contributor.author	Haines, Keith	en
dc.contributor.author	Wu, Peili	en
dc.date.accessioned	2015-01-25T19:53:14Z
dc.date.available	2015-01-25T19:53:14Z
dc.date.issued	2015-01-25
dc.identifier.uri	http://hdl.handle.net/11400/4722
dc.rights	Αναφορά Δημιουργού-Μη Εμπορική Χρήση-Όχι Παράγωγα Έργα 3.0 Ηνωμένες Πολιτείες	*
dc.rights.uri	http://creativecommons.org/licenses/by-nc-nd/3.0/us/	*
dc.subject	Mediterranean Sea
dc.subject	Winds
dc.subject	Barotropic
dc.subject	Άνεμοι
dc.subject	Μεσόγειος θάλασσα
dc.title	Altimetric assimilation in a Mediterranean general circulation model.	en
heal.type	journalArticle
heal.classification	Ophthalmology
heal.classification	Optics
heal.classification	Οφθαλμολογία
heal.classification	Οπτική
heal.classificationURI	http://skos.um.es/unescothes/C02842
heal.classificationURI	http://skos.um.es/unescothes/C02847
heal.classificationURI	N/A-Οφθαλμολογία
heal.classificationURI	N/A-Οπτική
heal.keywordURI	http://id.loc.gov/authorities/subjects/sh85083236
heal.identifier.secondary	DOI: 10.1029/97JC00367
heal.language	en
heal.access	free
heal.recordProvider	Τ.Ε.Ι. Αθήνας, Σχολή Επαγγελμάτων Υγείας & Πρόνοιας, Τμήμα Οπτικής & Οπτομετρίας	el
heal.bibliographicCitation	Drakopoulos, P.G., Haines, K.and Wu, P. (1997). Altimetric assimilation in a Mediterranean general circulation model . Journal of Geophysical Research 102 (C5), 15/05/1997, pp. 10509-10523. Available from: http://onlinelibrary.wiley.com/doi/10.1029/97JC00367/abstract [Accessed 20/09/2012]	en
heal.abstract	Identical twin experiments are performed with a realistic Mediterranean general circulation model, assimilating surface pressure at the rigid lid (simulating altimeter data) in order to reproduce the three-dimensional circulation and water column structure. The first twin pair is forced with monthly varying wind stress and surface buoyancy, and the assimilation method of Cooper and Haines [1996] is used. Water columns are displaced vertically by an amount calculated to ensure that the surface pressure change required at assimilation time is reduced to zero at the seabed. The assimilation is successful with T, S and velocities having an error reduction of about 40% after 1 year, assimilating surface pressure every 15 days. A modification to this assimilation method is introduced in which a change to bottom pressure is calculated based on a balance between relative vorticity and stretching in the vertically displaced water column. A second identical twin experiment pair is forced with daily varying wind stress (from the European Centre for Medium-Range Weather Forecasts in 1992-1993) but still monthly varying surface buoyancy forcing. The variability in surface pressure is much greater when daily winds are used, with much of the high-frequency current signal being a barotropic response (with a strong signal at the seafloor). Applying the correct daily winds without any surface pressure assimilation can reduce the T, S and velocity errors by about 50% after a year, suggesting that much of the additional barotropic variability is deterministic. The additional assimilation of surface pressure every 20 days, now with the bottom pressure updated, leads to a further 30% error reduction. A further twin experiment with daily winds, in which the barotropic mode is allowed to converge first, before surface pressure assimilation begins, shows that a bottom pressure update during assimilation may be unnecessary if the correct wind stresses are known.	en
heal.journalName	Journal of Geophysical Research	en
heal.journalType	peer-reviewed
heal.fullTextAvailability	true
heal.dateCreated	1997-05-15