Accueil > Actualités > Séminaires > Séminaire de Karina VON SCHUCKMANN


Titre : Estimation of global ocean indicators from Argo with focus on regional and deep ocean contributions to global steric sea level
Nom du conférencier : Karina VON SCHUCKMANN
Son affiliation : IFREMER
Laboratoire organisateur : LOCEAN
Date et heure : 15-11-2011 12h15
Lieu : LOCEAN, UPMC, 4 place Jussieu, Paris 5e, Tour 45-55, 4ème étage, salle de séminaire
Résumé :

Argo temperature and salinity measurements during the period 2005 to 2010 are used to estimate global ocean indicators (GOIs) such as global ocean heat content (GOHC), global ocean freshwater content (GOFC) and global steric sea level (GSSL). A method based on a simple box averaging scheme is developed to estimate GOIs, together with an error estimation due to data sampling, data processing and climatology uncertainties. Over the six year time period, trends of GOHC and GSSL are 0.55±0.1 W/m2 and 0.69±0.14 mm/yr, respectively. The trend of GOFC is barely significant. Interannual variability at global scale can be observed, especially for GOFC.

These results are valid under the assumption that no systematic errors remain in the global observing system. In addition, regional and deep ocean (700-2000m) contributions to the Argo GSSL estimation are analyzed. Results show that previously neglected deep ocean and salinity effects have a significant impact on estimations of GSSL. Space scales of coherent patterns increase with increasing depth due to both temperature and salinity effects. As already shown in previous studies, density changes due to salinity effects compensate temperature changes in large areas of the global ocean. Steric sea level increase due to salinity effects alone occur as well and can reach down to 2000m depth. A comparison of Argo steric sea level to total sea level from satellite altimetry (AVISO) reveals that largest regional contributions to both GSSL and global total sea level can be observed in the global tropical basin.

Contact :

Giovanni Aloisi