Leeuwin Current facts for kids
The Leeuwin Current is a warm ocean current that flows south along the western coast of Australia. It goes around Cape Leeuwin and continues into the waters south of Australia, reaching as far as Tasmania. This current is quite special because it brings warm, tropical water to a part of the world where ocean currents are usually much cooler.
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What Makes the Leeuwin Current Special?
Most ocean currents along the west coasts of continents in similar parts of the world are cold. For example, the California Current brings cool, foggy weather to San Francisco. But the Leeuwin Current is different; it's warm! This makes the waters off Western Australia warmer in winter and cooler in summer compared to other places.
This warm current helps tropical marine life, like the most southerly true corals found at the Abrolhos Islands, to thrive. It also carries other tropical sea creatures down the west coast and into the Great Australian Bight.
How Fast Does It Flow?
The Leeuwin Current usually moves at about 1 knot (which is about 50 centimeters per second). Sometimes, it can speed up to 2 knots (1 meter per second). The fastest speed ever recorded by a special buoy was 3.5 knots (about 6.5 kilometers per hour)!
This current is also quite shallow for a major ocean current, only about 300 meters deep. Below it, there's another current flowing north, called the Leeuwin Undercurrent.
When Is the Current Strongest?
The strength of the Leeuwin Current changes throughout the year.
- It is weakest during the summer months (from November to March). This is when strong winds blow from the southwest towards the north, pushing against the current.
- The current flows strongest in autumn and winter (from March to November). During these months, the winds that oppose the current are weaker, allowing it to flow more freely.
The warm water evaporating from the Leeuwin Current during autumn and winter helps bring a lot of rain to the southwest part of Western Australia.
How Do We See the Current?
Scientists can often spot the Leeuwin Current by looking at the ocean's surface temperature. The "core" of the current is usually warmer than the water further offshore.
- Near North West Cape, the temperature difference across the current is about 1°C.
- Off Fremantle, it can be 2° to 3°C warmer.
- Near Albany in the Great Australian Bight, the difference can be more than 4°C!
The current often forms swirling patterns called eddies, which can spin both clockwise and anti-clockwise.
How Does El Niño Affect It?
The Leeuwin Current is affected by a climate pattern called El Niño. During El Niño conditions, the sea temperatures along the Western Australian coast are a bit lower, and the Leeuwin Current becomes weaker. This can also change rainfall patterns in the region.
Who Discovered It?
The idea of this warm current was first suggested in 1897 by William Saville-Kent. He noticed that the water offshore at the Houtman Abrolhos was much warmer in winter than the water closer to the coast. This suggested a warm current was flowing there.
Over the years, more evidence confirmed the current's existence. However, it wasn't fully described and given its name until the 1980s by scientists Cresswell and Golding.
Images for kids
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Data from two satellite instruments is used in constructing this image of the Leeuwin Current.
See also
In Spanish: Corriente de Leeuwin para niños
