Major ocean currents and how they affect global temperatures

Hi everyone,

This week we're talking about ocean currents. Ocean currents are part of the ocean's circulation system and influence local and global weather patterns. They are produced by gravity, differences in water density, winds on the ocean surface and Earth's rotation on its own axis. They cause the movements and exchanges of different ocean properties such as salinity, temperature and nutrients. Ocean currents can flow at speeds of up to 4m per second however most flow at speeds between 5cm and 50cm per second. Weather patterns and ocean currents constantly influence one another. Ocean currents follow similar paths as global wind do, transferring heat from the equator to polar regions. They create and influence ecosystems worldwide, especially marine ones. However they also spread plastics and microplastics around the world far from their original source. This system of ocean currents is often referred to as a global conveyor belt. Today we're going to look at six major ocean currents.

Gulf Stream

The Gulf Stream is caused by movement of water in the Gulf of Mexico. It flows from the Caribbean up the eastern coast of the USA, before crossing the Atlantic and flowing towards the western coast of Europe. It is a warm surface current, meaning that it transports warm water to northeastern USA and into the Atlantic. As it reaches higher latitudes, it cools and the water sinks before flowing back towards the tropics. This current regulates the temperature in the North Atlantic region and causes milder winters in Western Europe.

Gulf Stream

California Current

This current flows from the arctic, down the west coast of the USA and towards the equator. Arctic waters are known to be very rich in nutrients, so this cold, nutrient-rich current flows southwards and has a significant effect on local ecosystems. It is vital for many sea creatures especially marine mammals such as dolphins and whales.

California Current

Kuroshio Current

The Kuroshio Current is caused by movements in western Pacific waters as the sun heats the ocean. This warm water flows up the east coast of Japan. It regulates the temperature in the North Pacific region and leads to milder winters in Japan and some other East Asian countries. It also serves as a migration route for many species.

Kuroshio Current

Agulhas Current

This current flows southwards down the East coast of Africa. It impacts the temperatures across the Indian Ocean Region and transports warmer water towards South Africa. This leads to higher temperatures in southeastern Africa. This current is also an important migration route.

Antarctic Circumpolar Current

The Antarctic Circumpolar Current is a cold surface current around Antarctica. It also transports cold water to the tropics. This current regulates the temperature of the Southern Ocean region and the coastal areas of Antarctica.

Antarctic Circumpolar Current

Thermohaline Circulation

The Thermohaline Circulation is a global deep current. It's caused by differences in water density. Transporting warm water to the poles and cold water to the tropics, it affects surface temperatures worldwide and distributes heat and nutrients.