Methods for estimating the velocities of the Brazil Current in the pre-salt reservoir area off southeast Brazil (23(a similar to) S-26(a similar to) S)

Author(s)

Bilo, Tiago Carrilho ^[1] ; Almeida da Silveira, Ilson Carlos ^[1] ; Belo, Wellington Ceccopieri ^[2] ; de Castro, Belmiro Mendes ^[1] ; Piola, Alberto Ricardo ^{[3, 4]}

Affiliation

^[1] Univ Sao Paulo, Inst Oceanog, Sao Paulo - Brazil

^[2] Ctr Pesquisas & Desenvolvimento Leopoldo A Miguez, Petroleo Brasileiro, SA - Brazil

^[3] Univ Buenos Aires, Secc Dinam Ocean, SHN, Buenos Aires, DF - Argentina

^[4] Consejo Nacl Invest Cient & Tecn, Inst Francoargentino Estudios Clima & Impactos, RA-1033 Buenos Aires, DF - Argentina

• Document type: Journal article
• Source: OCEAN DYNAMICS; v. 64, n. 10, p. 1431-1446, OCT 2014.
• Web of Science Citations: 8

Abstract

The Brazil Current (BC) is likely the least observed and investigated subtropical western boundary current in the world. This study proposes a simple and systematic methodology to estimate quasi-synoptic cross-sectional speeds of the BC within the Santos Basin (23(a similar to) S-26(a similar to) S) based on the dynamic method using several combinations of data: Conductivity, temperature, and depth (CTD), temperature profiles, CTD and vessel-mounted Acoustic Doppler Current Profiler (VMADCP), and temperature profiles and VMADCP. All of the geostrophic estimates agree well with lowered Acoustic Doppler Current Profiler (LADCP) velocity observations and yield volume transports of -5.56 +/- 1.31 and 2.50 +/- 1.01 Sv for the BC and the Intermediate Western Boundary Current (IWBC), respectively. The LADCP data revealed that the BC flows southwestward and is similar to 100 km wide, 500 m deep, and has a volume transport of approximately -5.75 +/- 1.53 Sv and a maximum speed of 0.59 m s(-1). Underneath the BC, the IWBC flows northeastward and has a vertical extent of approximately 1,300 m, a width of similar to 60 km, a maximum velocity of similar to 0.22 m s(-1), and a volume transport of 4.11 +/- 2.01 Sv. Our analysis indicates that in the absence of the observed velocities, the isopycnal (sigma (0)) of 26.82 kg m(-3) (similar to 500 dbar) is an adequate level of no motion for use in geostrophic calculations. Additionally, a simple linear relationship between the temperature and the specific volume anomaly can be used for a reliable first estimate of the BC-IWBC system in temperature-only transects. (AU)

• FAPESP's process: 12/05221-2 - The Brazil Current System in the Santos Bifurcation Region (25S): Direct Velocity Observations.
• Grantee: Tiago Carrilho Biló
• Support type: Scholarships in Brazil - Scientific Initiation
• FAPESP's process: 13/10475-6 - Santos Bifurcation Three-dimensional Structure and Dynamical Consequences (23-30S)
• Grantee: Tiago Carrilho Biló
• Support type: Scholarships in Brazil - Master