Aquarius sea surface salinity in the South Indian Ocean: Revealing annual‐period planetary waves. Issue 6 (20th June 2014)

• Record Type: Journal Article
• Authors: Menezes, Viviane V.; Vianna, Marcio L.; Phillips, Helen E.
• Is Part Of: Journal of geophysical research. Volume 119:Issue 6(2014:Jun.)
• Page Start: 3883
• Page End: 3908
• Publication Date: 2014-06-20
• Subjects: Oceanography -- Periodicals; 551.4605
• DOI: 10.1002/2014JC009935
• Languages: English
• ISSNs: 2169-9275

Abstract

<abstract abstract-type="main"> <title>Abstract</title> <p>A new milestone has been reached with the launch of two dedicated satellite missions to routinely measure the sea surface salinity (SSS) fields from space at global and regional scales. In the present work, a thorough analysis of the first 2 years of Aquarius SSS data in the South Indian Ocean is performed. This analysis is focused on three questions: How accurate is Aquarius SSS related to in situ data from the fresh Indonesian Throughflow and salty subtropical waters? Can Aquarius give a spatial context for the data measured by the RAMA mooring system? Are westward propagating annual‐period signals described in recent model simulations reproduced by Aquarius‐derived SSS? We find Aquarius observations to be highly correlated with those of Argo floats, with small disagreements occurring near oceanic fronts. Aquarius gives fresher SSS than in situ data in the tropical region due to rainfall effects, except in the eastern basin where the freshening seems to be related to sharp localized leakages of very fresh waters from the Indonesian seas that the Aquarius product is not able to properly resolve. Aquarius data are shown to reproduce quite well the annual cycle obtained from RAMA and Argo gridded data sets. The annual cycle in Aquarius is characterized by SSS propagating features with different characteristics west and east of the Ninety East Ridge. These features are strikingly different from sea surface height waves. Our results suggest that SSS annual propagation might be reflecting coupled ocean‐atmosphere dynamics and surface‐subsurface processes operating over the entire South Indian Ocean.</p> </abstract>