Ocean Currents — Key Concepts and Major Currents

Global circulation and driving forces

• Surface currents are driven by wind patterns: trade winds (tropics) push westward; westerlies push eastward at mid-latitudes.
• Coriolis force deflects flows: to the right in the Northern Hemisphere, to the left in the Southern Hemisphere.
• Winds + Coriolis + coastline shape ocean gyres and boundary currents.

Gyres and boundary currents

• Subtropical gyres dominate each ocean basin.
• Western boundary currents (warm, fast): Gulf Stream, Kuroshio, Brazil Current.
• Eastern boundary currents (cold, shallow): Labrador, Humboldt/Peru, Canary, Benguela, California.

Major currents: Atlantic

• Gulf Stream: warm current along the US East Coast; transports heat toward the NE Atlantic.
• North Atlantic Drift: extension of Gulf Stream toward NW Europe; contributes to regional warmth.
• Labrador Current: cold current along NE North America; cools coastal regions.
• Canary Current: NW Africa; part of eastern boundary current system.
• Benguela Current: SW Africa; cold, supports coastal deserts via upwelling.
• Humboldt (Peru) Current: cold water along western South America; highly productive upwelling zone.
• Brazil Current: warm current along Brazil coast.
• Norwegian Current: along the Norwegian coast; moderates European climate.

Major currents: Pacific

• Kuroshio Current: warm current off the coast of Japan.
• Tsushima Current: branch of the Kuroshio near Korea/Japan.
• Oyashio Current: cold current off the NW Pacific near Japan.
• California Current: cold current along the US West Coast.
• Alaska Current: regionally warm current along Alaska.
• Bering Current: flows into the Bering Sea.
• North Pacific Current: eastward flow across mid-latitudes.
• Kurile Current: near the Kuril Islands.
• Okhotsk Current: cold current in the Okhotsk Sea.
• Aleutian Currents: region around the Aleutian Islands.
• Peru Current / Humboldt Current: cold water along the western coast of South America; upwelling zone.
• Australian Current: warm current along eastern Australia (South Pacific).

Climate impacts of currents

• Gulf Stream + North Atlantic Drift keep NW Europe and NE North America warmer than latitude would predict.
• Labrador Current cools the NE North American coast.
• Canary Current & Benguela Current contribute to arid coastal climates via cooling and upwelling.
• Upwelling zones (Peru, Benguela) support high biological productivity and fisheries.

El Niño and climate variability

• El Niño alters typical current patterns and global weather; regional anomalies in heating, rainfall, and fisheries.