Malvinas Current

Malvinas Current
Name	Malvinas Current
Other names	Falkland Current
Location	South Atlantic Ocean
Type	Cold, northward-flowing boundary current
Source	Antarctic Circumpolar Current
Terminus	Brazil-Malvinas Confluence
Speed	0.1–0.5 m/s (typical)
Depth	surface to 1,000 m (variable)
Coordinates	50°S to 35°S

Malvinas Current The Malvinas Current is a cold, northward-flowing ocean current off the eastern coast of Argentina that carries waters from the Southern Ocean and Antarctic Circumpolar Current toward the South Atlantic Ocean and the Brazil Current confluent zone. It influences the climate of the Patagonia coast, the productivity of the South American Shelf, and the location of the Brazil–Malvinas Confluence where distinct water masses meet. The current plays a central role in regional fisheries and has been the subject of studies by institutions such as the National Oceanic and Atmospheric Administration, British Antarctic Survey, Instituto Nacional de Investigación y Desarrollo Pesquero, and numerous oceanographic research programs.

Overview

The Malvinas Current transports cold, low-salinity water from the vicinity of South Georgia (island), South Sandwich Islands, and the Scotia Sea northward along the Patagonian Shelf toward the Río de la Plata and the Uruguay-Brazil offshore region. Its interaction with the subtropical Brazil Current establishes a dynamic frontal zone near the Falkland Islands that affects Buenos Aires coastal climate and regional hydrography. Oceanographers from Scripps Institution of Oceanography, Woods Hole Oceanographic Institution, Lamont–Doherty Earth Observatory, and CSIC have mapped the current using ARGO floats, satellite altimetry, and shipboard hydrography.

Oceanography and Physical Characteristics

The current is characterized by temperatures typically between 2–12 °C and salinities lower than adjacent subtropical waters, reflecting input from Antarctic Intermediate Water and Subantarctic Mode Water. Vertically, it can extend from the surface to depths exceeding 1,000 m where Antarctic Bottom Water and Circumpolar Deep Water influence stratification near the Malvinas Plateau. Cross-shelf exchanges are modulated by mesoscale eddies, meanders, and fronts analogous to features observed at the Gulf Stream, Kuroshio Current, and Agulhas Current. Instrumentation campaigns by European Space Agency, NASA, and national research vessels have documented velocities ranging from 0.1 to 0.5 m/s and spatial variability influenced by wind forcing associated with the South Atlantic High and the South Atlantic Convergence Zone.

Formation and Seasonal Variability

The origin of the current lies in the northwestward diversion of Antarctic Circumpolar Current jets as they encounter the South American continental margin and the Malvinas/Falkland Plateau. Seasonal shifts in the position and intensity of the current correlate with the meridional movements of the Antarctic Polar Front and the seasonal cycle of the Southern Annular Mode, the latter linked to climate modes including the El Niño–Southern Oscillation and the Pacific Decadal Oscillation. Interannual variability has been associated with changes observed during Southern Hemisphere climate anomalies recorded by IPCC assessments and long-term datasets from Global Ocean Observing System deployments.

Interaction with Other Currents and Water Masses

A defining feature is the sharp confluence with the northward-flowing Brazil Current, forming the Brazil–Malvinas Confluence, a mixing zone comparable to the confluences at the Gulf Stream and the Agulhas Return Current. This boundary concentrates heat, nutrients, and biota and generates strong frontal jets and upwelling that influence fisheries near the Patagonian Shelf and Falkland Islands. Exchanges with Antarctic Intermediate Water, Subtropical Shelf Water, and intrusions of Warm Core Rings result in episodic transport of heat toward the shelf and modulate pelagic and demersal habitats studied by researchers from CONICET, NIWA, CSIC, and university groups at University of Buenos Aires, University of Cape Town, and University of São Paulo.

Ecological and Biological Impacts

The cold, nutrient-rich flow supports high primary productivity by promoting phytoplankton blooms that sustain zooplankton, including krill and copepods, which are prey for seabirds such as albatrosses and penguins (e.g., Magellanic penguin), marine mammals including southern right whale and southern elephant seal, and commercial fish species like anchoveta-type stocks and Patagonian hake. The confluence zone is a biodiversity hotspot with biologically important areas influencing migration routes of tunas and swordfish, monitored by programs like the Commission for the Conservation of Antarctic Marine Living Resources and regional fisheries management organizations. Ecologists from World Wildlife Fund, BirdLife International, and national agencies have linked shifts in the current to changes in breeding success of seabirds and distribution of squid fisheries.

Human Uses and Economic Significance

The current shapes commercial activities along the Argentine Sea and offshore Uruguay and Brazil waters, affecting fisheries for hake, squid, and pelagic species targeted by fleets from Spain, China, Russia, Japan, and Argentina itself. Shipping routes between Cape Horn and Buenos Aires navigate current and wind-driven conditions influenced by the Malvinas Current, while offshore energy exploration near the Pelotas Basin and North Falklands Basin considers oceanographic constraints. Conservation and governance involve stakeholders such as International Maritime Organization, regional fisheries commissions, and national ministries in Argentina, the United Kingdom (concerning the Falkland Islands), and neighboring states. Climate change projections from IPCC models suggest alterations in current strength with implications for regional economies, prompting research collaborations among SCAR, IOC, and university consortia.

Category:Ocean currents Category:South Atlantic Ocean Category:Physical oceanography