A regional study of the Brazilian shelf/slope circulation (13°-31°s) using climatological open boundaries

Abstract

The oceanic features in the eastern and southeastern Brazilian shelf/slope between 13°-31°S are investigated using ROMS (Regional Ocean Model System). The model was integrated for 9 years and it was forced with: i) 6-hourly synoptic atmospheric data from NCEP; ii) initial and boundary conditions from OCCAM (Ocean Climate Circulation Advanced Modelling) monthly mean climatology and iii) tidal forcing from TPXO 7.1 global data set. The model results were compared with observations, which consisted in thermodynamic MDL (Mixed Layer Depth) climatology, satellite data, measurements from tide gauges along the shelf and currents measurements values from literature. The simulated currents represented the BC (Brazil Current)-IWBC (Intermediate Western Boundary Current) System. The BC-IWBC system at 22′S cross-shelf section represents our simulation capability of reproducing the western boundary currents, it showed poleward BC and a opposing IWBC. At this section, the BC velocity core is in 50 m with 0.41 m.s-1 and the IWBC core around 800 m with 0.15 m.s-1. © 2013 Sociedade Brasileira de Geofísica.