Temporal variations in the separation of Brazil and Malvinas Currents

doi:10.1016/0198-0149(88)90120-3

Deep Sea Research Part A. Oceanographic Research Papers

Volume 35, Issue 12, December 1988, Pages 1971-1990

https://doi.org/10.1016/0198-0149(88)90120-3 Get rights and content

Abstract

The separation of the Brazil and Malvinas (Falkland) Currents from the western boundary is explored with the use of satellite and drifter data. The location of the separation of these boundary currents from the continental margin over a multiyear period is determined by digitizing the crossing of the surface thermal front indicative of each feature with the 1000 m isobath. Three years (July 1984 to June 1987) of 1 km resolution AVHRR data collected by the Argentina Meteorological Service and 4 years of lower resolution Global Retrieval Tape (GRT) data were used to generate a total time series extending from November 1981 to June 1987; i.e. $512$ years.

The mean latitudes of separation from the shelf break are 35.8 ± 1.1° for the Brazil Current and 38.6 ± 0.9° for the Malvinas Current. The along-coast ranges of the separation positions, 930 and 850 km, respectively, are quite large relative to similar statistics for the Gulf Stream or Kuroshio. Observed temporal variability suggests cyclical excursions of the currents along the coast at semi-annual and annual periods, although there is considerable interannual variation in the signal. Drifter trajectories overlaid on satellite images demonstrate events associated with the annual transition in 1984–1985. Shorter time-scale perturbations in the currents' separation latitudes occur in the 30–60 day band, which corresponds to the mesoscale eddy field. The connection of the variation in the separation with various possible forcing mechanisms is briefly discussed, along with the problem of gaining a theoretical understanding of this dynamic situation. Finally, the extensions of the two currents into the South Atlantic interior are described statistically using the high resolution data set.

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^∗∗: Present address: NASA Goddard space Flight Center, Code 671, Greenbelt, MD 20771, U.S.A.

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Temporal variations in the separation of Brazil and Malvinas Currents

Abstract

Remote Sensing of the Environment

Deep-Sea Research

Deep-Sea Research

Deep-Sea Research

Deep-Sea Research

Progress in Oceanography

Deep-Sea Research

La zona de convergencia subtropical/subantártica en el Océano Atlántico (parte occidental)

Masas de agua (característica, distribución, movimientos) en la superficie del Atlántico sudoeste, según indicadores bioloógicos-Foraminíferos

Evaluación de los recursos de anchoíta (Engraulis anchoita) frente a la Argentina y Uruguay. I. Las condiciones oceanográficas, sinópsis del conocimiento actual sobre la anchoíta y el plan para su evaluación

Some results of oceanographical observations in the convergence area between the Falkland Current and the Brazil Current

Calibration of advanced very high resolution radiometer infra-red observations

Journal of Geophysical Research

On the theory of the wind driven ocean circulation

Journal of Fluid Mechanics

The Gulf Stream as an inertial boundary layer

The hydrology of the southern ocean

Discovery Reports

Quantitative Untersuchungen zur Statik und Dynamik des Atlantischen Ozeans

Wissenschaftliche Ergebnisse der Deutschen Atlantischen Expedition “Meteor”

Steady flow in a frictionless homogeneous ocean

Journal of Marine Research

Transports, frontal motions and eddies at the Brazil-Malvinas Currents Confluence

Deep-Sea Research

A criterion for the existence of inertial boundary layers in oceanic circulation

A note concerning topography and inertial currents

Journal of Marine Research

The structure and transport of the Gulf Stream at 73°W

Journal of Physical Oceanography

Normal monthly wind stress over the world ocean with Error estimates

Journal of Physical Oceanography

A contribution to the theory of stationary wind-driven currents in a two-layer liquid

Izvestya, Atmospheric and Oceanic Physics

Formation process of a warm-core ring in the Kuroshio-Oyashio frontal zone—December 1986–October 1982

Deep-Sea Research

A survey of worldwide sea surface temperature fronts detected by environmental satellites

Journal of Geophysical Research

Aportes al conocimiento de las masas de agua del Atlántico sudoccidental Publceción Servicio de Hidrografia Naval H659