Why in the News?
Researchers have found that the Antarctic Circumpolar Current (ACC) is slowing due to melting ice sheets. By 2050, it may weaken by 20%, affecting global climate, ocean circulation, and marine ecosystems.
What is the Antarctic Circumpolar Current (ACC)?
- The ACC is the strongest and largest ocean current on Earth.
- It flows continuously from west to east around Antarctica, acting as a boundary between the Southern Ocean and the Atlantic, Pacific, and Indian Oceans.
- It flows from west to east, driven by the westerly winds and the Coriolis effect, creating a loop that completely encircles Antarctica.
- The ACC interacts with several regional currents, such as the Brazil Current, East Australian Current, and Agulhas Current.
- It is influenced by both westerly winds and polar easterlies, which affect its strength and flow patterns.
- Key features of the ACC:
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- It is five times stronger than the Gulf Stream and transports 130 million cubic meters of water per second.
- It plays a crucial role in global heat and nutrient distribution, influencing climate patterns worldwide.
- It prevents warmer northern waters from reaching Antarctica, helping to preserve the region’s ice sheets.
- The ACC drives the global conveyor belt, regulating deep ocean currents and heat flow.
- Its upwelling of nutrient-rich waters sustains Antarctic marine life, including krill, whales, and penguins.
Why does Antarctic Ice Melt affect ACC?
- Freshwater Dilution: Melting ice lowers salinity, weakening ocean density gradients that drive the ACC.
- Slower Heat Exchange: Reduced current strength disrupts global heat distribution, leading to stronger storms and rising sea levels.
Key Findings of the New Research
A study by the University of Melbourne and NORCE Norwegian Research Centre, published in Environmental Research Letters, reveals:
- ACC could slow by 20% by 2050 due to melting ice sheets.
- Disrupted global climate as a weaker ACC reduces heat distribution, carbon absorption, and weather stability.
- Antarctic ecosystem at risk, with invasive species threatening penguins, krill, and whales.
- Supercomputer simulations confirm that deep ocean circulation is slowing, worsening climate instability.
- Reducing carbon emissions is crucial to prevent further ice melting and ACC weakening.
PYQ:[2012] Consider the following factors: 1. Rotation of the Earth 2. Air pressure and wind 3. Density of ocean water 4. Revolution of the Earth Which of the above factors influence the ocean currents? (a) 1 and 2 only (b) 1, 2 and 3 (c) 1 and 4 (d) 2, 3 and 4 |
