Data/hora: 05/06/2024 05:47:46

Provedor de dados: | 5
País: | France
Título: | Etude de la variabilité de la circulation du gyre subpolaire de l'Atlantique Nord à partir des données Ovide et de mesures satellitaires
Autores: | Gourcuff, Claire.
Data: | 2008-10-21
Ano: | 2008
Palavras-chave: | Inverse Model; Courantology; Geostrophy; Altimetry; East Greenland Coastal Current; Freshwater fluxes; Heat transport; Meridionnal Overturning Circulation (MOC); Variability; North Atlantic; Subpolar gyre; Ovide; Modèle inverse; Géostrophie; Courantométrie; Altimétrie; Courant Côtier Est Groenlandais; Flux d'eau douce; Transport de chaleur; Circulation Méridienne de Retournement (MOC); Variabilité; Atlantique Nord; Gyre subpolaire; Ovide.
Resumo: | The cyclonic circulation of the North Atlantic subpolar gyre, between 50°N and 63°N, plays a key role in the climate variability. The Ovide program contributes to the observation of the circulation in this region. A section is repeated every two years in summer since 2002 between Greenland and Portugal following a path close the Fourex 1997 section. To get transport estimates across the sections, a geostrophic box inverse model is used, constrained with direct current measurements.  Our new estimates of Fourex transports show the need to use constraints temporally associated with the section to get transports estimates representative of the circulation at the section realisation dates. It is also shown that altimetry velocities can be used instead of ADCP measurements to get transports across sections with the inverse model, provided that the a priori errors is correctly evaluated.  Analysis of circulation across Ovide 2006 section display significantly weaker transports compared to 1997, 2002 and 2004, for all the main currents as well as for the Meridional Overturning Cell and the heat transport. Altimetry is used to interpret surface variability along the Ovide section from 1992 to 2007. An index is defined, which seems to indicate that northward surface transport was especially low during the whole year 2006 and turn back to less extreme values in the following years.  Variability in freshwater fluxes across Fourex 1997, Ovide 2002, 2004 and 2006 sections is revealed in the last chapter, together with the EGCC position. This coastal current transport represents 15% of the total freshwater transport across the section.
Tipo: | Text
Idioma: | Francês
Identificador: | http://archimer.ifremer.fr/doc/2008/these-6226.pdf
Editor: | Université de Bretagne Occidentale
Relação: | http://archimer.ifremer.fr/doc/00000/6226/
Formato: | application/pdf