Éditeur(s) : Amer Geophysical Union
Résumé : Sea surface salinity (SSS) measured from space by the Soil Moisture and Ocean Salinity (SMOS) mission is validated in the subtropical North Atlantic Ocean. 39 transects of ships of opportunity equipped with thermosalinographs (TSG) crossed that region from 2010 to 2012, providing a large database of ground truth SSS. SMOS SSS is also compared to Aquarius SSS. Large seasonal biases remain in SMOS and Aquarius SSS. In order to look at the capability of satellite SSS to monitor spatial variability, especially at scales less than 300 km (not monitored with the Argo network), we first apply a monthly bias correction derived from satellite SSS and In Situ Analysis System (ISAS) SSS differences averaged over the studied region. Ship SSS averaged over 25 km is compared with satellite and ISAS SSS. Similar statistics are obtained for SMOS, Aquarius and ISAS products (root mean square error of about 0.15 and global correlation coefficient r of about 0.92). However, in the above statistics, SSS varies due to both large scale and mesoscale (here, for scales around 100 km) variability. In order to focus on mesoscale variability, we consider SSS anomalies with respect to a monthly climatology. SMOS SSS and Aquarius SSS anomalies are more significantly correlated (r > 0.5) to TSG SSS anomaly than ISAS. We show the effective gain of resolution and coverage provided by the satellite products over the interpolated in situ data. We also show the advantage of SMOS (r=0.57) over Aquarius (r=0.52) to reproduce SSS mesoscale features.
Journal Of Geophysical Research-oceans (0148-0027) (Amer Geophysical Union), 2014-12 , Vol. 119 , N. 12 , P. 8878-8896

Droits : 2014. American Geophysical Union. All Rights Reserved.
http://archimer.ifremer.fr/doc/00210/32150/34082.pdf
DOI:10.1002/2013JC009610
http://archimer.ifremer.fr/doc/00210/32150/

Éditeur(s) : Amer Geophysical Union
Résumé : Intense currents having speeds between 10 and 40 cm.s(-1) from 1000 m below the surface to the bottom have been measured in the Loop Current (LC) region and in the Western Gulf of Mexico (WGM). The observations come from moored current meters sampling from the near-surface to the bottom at 3300-3500 m and from August 2008 to August 2010. Ten intermittent intensified currents are documented. These events last 10 to 30 days and take place in the region just between the surface-intensified anticyclonic-cyclonic features, as deduced from altimetry and measured currents. In the WGM, they occur between the cores of anticyclone-cyclone pairs. In the Eastern Gulf of Mexico (EGM), they occur in the Loop Current edge between its anticyclonic circulation and a neighboring cyclone. During each event, the analysis shows an increase in the barotropic contribution to the current. In the Loop Current region, these events are often associated with intensification of cyclonic vorticity in the deep layer.
Journal Of Geophysical Research-oceans (0148-0227) (Amer Geophysical Union), 2012-09-14 , Vol. 117 , N. C09014 , P. 20p.

Droits : 2012. American Geophysical Union. All Rights Reserved.
http://archimer.ifremer.fr/doc/00099/20994/18626.pdf
DOI:10.1029/2012JC007890
http://archimer.ifremer.fr/doc/00099/20994/