Science Meetings

A First Evaluation of Aquarius Sea Surface Density
Schanze, J.J. and Lagerloef, G. (18-Nov-15)

With the recent advent of remotely sensed sea-surface salinity (SSS) data, it has become possible to compute sea surface density by combining SSS with remotely sensed sea surface temperature (SST) data. The International Thermodynamic Equation of Seawater 2010 (TEOS-2010) is used with Aquarius SSS and the Aquarius ancillary SST product to compute sea surface density (SSD). The Aquarius SSD product provides a higher resolution of features than existing in-situ systems such as Argo or shipborne measurements. To validate the product, we compare Aquarius SSD with the in-situ-based MetOffice EN4 product and find generally good agreement, even including a slight seasonal bias. This bias appears as denser water in the Northern Hemisphere and lighter waters in the Southern Hemisphere during boreal summers. Most small-scale differences are located in areas of known mesoscale features, such as western boundary currents, the ITCZ, and riverine plumes. These differences are thus likely caused by the difference in resolution between the two products. Preliminary comparisons with other in-situ platforms in the North Atlantic, which were deployed during the Salinity Processes in the Upper Ocean Regional Study (SPURS) between 2012 and 2013, also show good agreement with Aquarius-derived density. Thus, we show that remotely sensed sea surface density can provide a new insight into oceanographic processes, including water-mass transformation and the influence of salinity on ocean dynamics.