From UPSC perspective, the following things are important :
Prelims level: Antarctic Circumpolar Current (ACC)
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 |
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