Warm Waters Are Moving Towards The Largest Ice Sheet In Antarctica

Warm Waters Are Moving Towards The Largest Ice Sheet In Antarctica

According To An Alarming Research, The Flow Of Warmer Waters Toward East Antarctica Will Be A New Driver In Increasing The Level Of Open Water.

 Ice Sheet In Antarctica, A study recently published in the journal Nature Climate Change suggests that changing water cycles in the Antarctic Ocean may threaten the stability of the East Antarctic Ice Sheet.

The change in the water cycle is due to the difference in the wind pattern related to factors such as climate change. The resulting warmer waters and rising sea levels can harm marine life and threaten human coastal settlements.

The findings of the authors of the article emphasize the necessity of limiting global warming to less than 1.5 degrees Celsius to prevent the most catastrophic climate damages.

Penguins in Antarctica

Ice sheets and climate change

Ice sheets are formed from glaciers resulting from the accumulation of precipitation on the surface of the earth. The plates are called ice shelves when they extend from the world’s surface to the middle of the ocean. The melting of the West Antarctic ice sheet and its effect on sea level rise are well known, But until now, we have less information about its eastern counterpart.

The new research focused on the Aurora Subglacial Basin in the Indian Ocean. This area of ​​sea ice forms part of the East Antarctic ice sheet. How this basin reacts to climate change is one of the significant uncertainties in predicting sea level rise in the last century. If this basin melts completely, the sea level will rise to 5.1 meters.

Most of this basin is located below sea level, which makes it more sensitive to ocean warming; Because deeper water needs a lower temperature than shallow water to freeze.

 

What we have understood

The researchers analyzed 90 years of observations from the Aurora subglacial basin and determined the ocean warming rate from the first half of the 20th century to 2 to 3 degrees Celsius. The warming trend has tripled since the 1990s, at a rate of 0.3 to 0.9 degrees Celsius per decade. It is equivalent to an increase of 0.1 to 0.4 degrees Celsius per decade.

How is this warming related to climate change? The answer has to do with a belt of strong westerly winds over the Antarctic Ocean. Since the 1960s, these winds have been directed towards Antarctica in the positive state of the Antarctic Oscillation, which is a climate driver.

This phenomenon is affected by the increase of greenhouse gases in the atmosphere, and as a result, the western winds are closer to Antarctica in summer and bring warm waters with them.

Previously, I thought it was that the East Antarctic ice sheet was largely stable and safe from the effects of ocean warming; Because the icy waters surrounding it were called “plateau dense water.”Part of the new research focuses on the Vanderford Glacier in East Antarctica. In this section, it was observed that warm water replaces the dense cold water of the plateau.

It is predicted that the movement of warm waters towards East Antarctica will intensify in the 21st century and threaten the stability of this ice sheet more.

Why is this important for marine life?

Previous research on the effects of climate change in East Antarctica assumed that warming occurs first in the sea surface layers. Recent findings that warming starts from deeper waters indicate the need to re-examine the possible consequences for marine life.

Wall in Antarctica

Changes in the ocean may occur much faster than marine life can adapt. More robust assessments, including monitoring and modeling, are needed to establish the relationship between physical changes and complex ecosystem responses. These assessments should include the potential impacts of rapid changes known as “tipping points.”

The East Antarctic marine ecosystem looks pretty vulnerable to warming waters. For example, Antarctic krill reproduce by sending their eggs into the deep ocean. Warming of deep waters can affect the development of eggs and larvae; As a result, krill populations and their dependent predators, such as penguins, terns, and whales, are affected.

Limiting global warming to less than 1.5 degrees Celsius

The researchers hope their results inspire international efforts to limit global warming to less than 1.5 degrees Celsius. Global greenhouse gas emissions must be reduced by 43% by 2030 and reach zero by 2050.

Warming of more than 1.5 degrees Celsius will significantly increase the risk of instability of the Antarctic ice sheet and cause a significant rise in sea levels. However, by keeping the temperature increase to fewer than 1.5 degrees Celsius, the sea level will not rise more than 0.5 meters by 2100, providing more opportunities for people and ecosystems to adapt.