On the TS relationship in the central region of the Southwest Atlantic: a contribution for the study of ocean variability in the vicinity of the Vitória-Trindade chain.

Abstract

The MOVAR (Monitoring the variability of heat transport between Rio de Janeiro-RJ and Trindade Island-ES) project was created in order to study the oceanic circulation south of the Vitória-Trindade seamount chain. The periodic sampling in the area is possible by using ships of opportunity to launch expendable bathythermographs (XBT). In order to investigate the oceanic volume flows using the geostrophic method based on the measured data, which is the temperature only, we have chosen to use a methodology based on the regional correlation between temperature and salinity (TS). Within this context, polynomials of order 1 to 10 were obtained and tested, in order to enable the estimation of salinity as a function of temperature. Hence, to reach this purpose, TS data from the WOD-05 (World Ocean Data Base 2005) as well as ARGO profiles available in the region were used. After a sequence of tests, the polynomials of first to fourth order were discarded, while the remaining polynomials were used to estimate the transport along three sections. The results obtained with the polynomials were very similar to each other leading to the choice of the simpler equation, P5, to represent the TS relation for the region. Estimates of transport were satisfactory and indicated that the polynomial can be used for this purpose.