Antarctic ice

Figure 1. Antarctica as viewed from space.[1]

Antarctic ice makes up a large portion of the geography in the great continent of Antarctica. With global warming effects becoming noticeable worldwide, one of the main concerns of scientists is to study the world's large bodies of ice, in order to observe melting ice and rising sea levels. The Antarctic ice sheet is of particular concern as the world gets warmer.

Features

Effects of climate change are discussed below, however it is first important to understand the features of Antarctic ice and how it differs from other ice sheets worldwide, most notably Arctic sea ice.

Thickness and Mobility

Antarctica is a land mass which is surrounded by an ocean. The open ocean allows the forming sea ice to move more freely, which results in higher drift speeds than compared to Arctic sea ice.[2] The mobility of Antarctic ice means that it does not have the opportunity to grow as thick as sea ice in the Arctic. As a result, sea ice does not stay in the Antarctic as long as it does in the Arctic.

While thickness varies significantly within both regions, Antarctic ice is typically 1 to 2 meters thick, while most of the Arctic is covered by sea ice 2 to 3 meters thick. Some Arctic regions are covered with ice that is 4 to 5 meters in thickness.[2]

Seasonal variance

Since there is no land boundary to the north, the sea ice is free to float toward the northern direction into warmer waters where it eventually melts. As a result, almost all of the sea ice that forms during the Antarctic winter melts during the summer and reforms during the winter season. During the winter, there is approximately 18 million km2 of ocean is covered by sea ice, but by the end of summer, roughly 3 million km2 of sea ice remains.[2]

In the Antarctic, the ocean currents and winds tend to flow around the continent from west to east, which acts like a barrier to warmer air and water to the north.[2] Antarctica, however, is entirely surrounded by ocean, hence moisture is more readily available.[2] Antarctic sea ice tends to be covered by thicker snow, which may accumulate to the point that the weight of snow pushes the ice below sea level, causing the snow to become flooded by salty ocean waters.[2]

Impacts of climate change on Antarctic Ice

Due to extreme low temperatures in Antarctica, there is little surface melting occurring on the ice sheet. Most of the ice loss is contributed to the deterioration of icebergs which is a long process.[3]

A rise in temperature isn’t sufficient enough to cause drastic melting in the Antarctic due to it’s ocean and wind currents that barricade warmer air. Scientists predict little change in the ice sheets in the next 50 years.[3] The critical region in Antarctica that is currently being discussed is the Antarctic Peninsula, which has shown a dynamic response in recent times. The Antarctic Peninsula receives 28% of the continents snowfall and experiences warmer temperatures than the rest of the continent.[3] Researchers state that a rise in temperature is expected to cause the ice shelves in the western peninsula to break off, however this has no direct impact on sea level rise nor does it indicate changes in the ice sheets.[3]

References

  1. Wikimedia Commons [Online], Available: https://upload.wikimedia.org/wikipedia/commons/0/07/Antarktyda_i_Antarktyka.jpg
  2. 2.0 2.1 2.2 2.3 2.4 2.5 "All About Sea Ice | Arctic vs. Antarctic | National Snow and Ice Data Center", National Snow & Ice Data Center, 2016. [Online]. Available: https://nsidc.org/cryosphere/seaice/characteristics/difference.html. [Accessed: 12- May- 2016].
  3. 3.0 3.1 3.2 3.3 "The Regional Impacts of Climate Change", Intergovernmental Panel on Climate Change, 2016. [Online]. Available: http://www.ipcc.ch/ipccreports/sres/regional/index.php?idp=46. [Accessed: 14- May- 2016].