Climate of Antarctica - Revision history

Westarctica: added link to Horlick Mountains article

2023-08-22T15:34:29Z

added link to Horlick Mountains article

← Older revision		Revision as of 15:34, 22 August 2023
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	[[File:Horlick Mountains.jpg\|thumb\|400px\|Snow and ice surrounding the Horlick Mountains]]		[[File:Horlick Mountains.jpg\|thumb\|400px\|Snow and ice surrounding the [[Horlick Mountains]]]]
	The '''Climate of Antarctica''' is the coldest on the Earth.		The '''Climate of Antarctica''' is the coldest on the Earth.

Westarctica at 06:49, 22 April 2019

2019-04-22T06:49:45Z

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	[[File:Horlick Mountains.jpg\|thumb\|400px\|Snow and ice surrounding the Horlick Mountains]]		[[File:Horlick Mountains.jpg\|thumb\|400px\|Snow and ice surrounding the Horlick Mountains]]
	[[Antarctica~~]] has~~ the coldest ~~climate~~ on the Earth.		The '''Climate of Antarctica''' is the coldest on the Earth.

	Antarctica's lowest air temperature record was set on 21 July 1983, with −89.2 °C (−128.6 °F) at Vostok Station in East Antarctica. Satellite measurements have identified even lower ground temperatures, down to −93.2 °C (−135.8 °F) at the cloud free East Antarctic Plateau on 10 August 2010. It is also extremely dry (technically a desert), averaging a mere 166 mm (6.5 in) of precipitation per year. On most parts of the continent the snow rarely melts and is eventually compressed to become the [[glacier]] ice that makes up the [[ice sheet]]. Weather fronts rarely penetrate far into the continent, because of the [[katabatic wind\|katabatic winds]]. Most of Antarctica has an ice cap climate (Köppen EF) with very cold, generally extremely dry weather.		Antarctica's lowest air temperature record was set on 21 July 1983, with −89.2 °C (−128.6 °F) at Vostok Station in East Antarctica. Satellite measurements have identified even lower ground temperatures, down to −93.2 °C (−135.8 °F) at the cloud free East Antarctic Plateau on 10 August 2010. It is also extremely dry (technically a desert), averaging a mere 166 mm (6.5 in) of precipitation per year. On most parts of the continent the snow rarely melts and is eventually compressed to become the [[glacier]] ice that makes up the [[ice sheet]]. Weather fronts rarely penetrate far into the continent, because of the [[katabatic wind\|katabatic winds]]. Most of Antarctica has an ice cap climate (Köppen EF) with very cold, generally extremely dry weather.

Westarctica: /* Global Warming */

2018-05-15T19:10:41Z

Global Warming

Westarctica at 19:07, 15 May 2018

2018-05-15T19:07:49Z

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	Nearly all of Antarctica is covered by a sheet of ice that is, on average, a mile thick or more (1.6 km). Antarctica contains 90% of the world's ice and more than 70% of its fresh water.		Nearly all of Antarctica is covered by a sheet of ice that is, on average, a mile thick or more (1.6 km). Antarctica contains 90% of the world's ice and more than 70% of its fresh water.

	If all the land-ice covering Antarctica were to melt — around 30 million cubic kilometers (7.2 million cubic miles) of ice — the ~~[[sea level rise\|~~seas would rise]] by over 60 meters (200 feet). This is, however, very unlikely to occur within the next few centuries. The Antarctic is so cold that even with increases of a few degrees, temperatures would generally remain below the melting point of ice. Higher temperatures are expected to lead to more snow, which would increase the amount of ice in Antarctica, offsetting approximately one third of the expected sea level rise from thermal expansion of the oceans. During a recent decade, East Antarctica thickened at an average rate of about 1.8 centimeters per year while West Antarctica showed an overall thinning of 0.9 centimeters per year. Because ice flows, albeit slowly, the ice within the ice sheet is younger than the age of the sheet itself.		If all the land-ice covering Antarctica were to melt — around 30 million cubic kilometers (7.2 million cubic miles) of ice — the seas would rise by over 60 meters (200 feet). This is, however, very unlikely to occur within the next few centuries. The Antarctic is so cold that even with increases of a few degrees, temperatures would generally remain below the melting point of ice. Higher temperatures are expected to lead to more snow, which would increase the amount of ice in Antarctica, offsetting approximately one third of the expected sea level rise from thermal expansion of the oceans. During a recent decade, East Antarctica thickened at an average rate of about 1.8 centimeters per year while West Antarctica showed an overall thinning of 0.9 centimeters per year. Because ice flows, albeit slowly, the ice within the ice sheet is younger than the age of the sheet itself.

	==Ice shelves==		==Ice shelves==

Westarctica at 16:57, 11 May 2018

2018-05-11T16:57:49Z

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			[[File:Horlick Mountains.jpg\|thumb\|400px\|Snow and ice surrounding the Horlick Mountains]]
	[[Antarctica]] has the coldest climate on the Earth.		[[Antarctica]] has the coldest climate on the Earth.

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	==Ice cover==		==Ice cover==
			[[File:Pine Island - rift.jpg\|thumb\|400px\|Major rift in the Pine Island Glacier]]
	Nearly all of Antarctica is covered by a sheet of ice that is, on average, a mile thick or more (1.6 km). Antarctica contains 90% of the world's ice and more than 70% of its fresh water.		Nearly all of Antarctica is covered by a sheet of ice that is, on average, a mile thick or more (1.6 km). Antarctica contains 90% of the world's ice and more than 70% of its fresh water.

Westarctica: /* Global Warming */

2018-05-11T16:55:10Z

Global Warming

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	==Global Warming==		==Global Warming==
			[[File:Global Warming Predictions.png\|thumb\|400px\|Calculations of global warming prepared in or before 2001 from a range of climate models under the SRES A2 emissions scenario, which assumes no action is taken to reduce emissions and regionally divided economic development]]
	::''Main article: [[Global warming]]''		::''Main article: [[Global warming]]''

Westarctica: /* Global Warming */

2018-05-11T16:53:35Z

Global Warming

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	==Global Warming==		==Global Warming==
	::''Main article: [[Global ~~Warming~~]]''		::''Main article: [[Global warming]]''

	The continent-wide average surface temperature trend of Antarctica is positive and significant at >0.05 °C/decade since 1957. The [[West Antarctic Ice Sheet]] has warmed by more than 0.1 °C/decade in the last 50 years, and is strongest in winter and spring. Although this is partly offset by fall cooling in East Antarctica, this effect is restricted to the 1980s and 1990s.		The continent-wide average surface temperature trend of Antarctica is positive and significant at >0.05 °C/decade since 1957. The [[West Antarctic Ice Sheet]] has warmed by more than 0.1 °C/decade in the last 50 years, and is strongest in winter and spring. Although this is partly offset by fall cooling in East Antarctica, this effect is restricted to the 1980s and 1990s.

Westarctica at 16:53, 11 May 2018

2018-05-11T16:53:20Z

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	==Global Warming==		==Global Warming==
	::''Main article:[[Global Warming ~~in Westarctica~~]]		::''Main article: [[Global Warming]]''

	The continent-wide average surface temperature trend of Antarctica is positive and significant at >0.05 °C/decade since 1957. The [[West Antarctic Ice Sheet]] has warmed by more than 0.1 °C/decade in the last 50 years, and is strongest in winter and spring. Although this is partly offset by fall cooling in East Antarctica, this effect is restricted to the 1980s and 1990s.		The continent-wide average surface temperature trend of Antarctica is positive and significant at >0.05 °C/decade since 1957. The [[West Antarctic Ice Sheet]] has warmed by more than 0.1 °C/decade in the last 50 years, and is strongest in winter and spring. Although this is partly offset by fall cooling in East Antarctica, this effect is restricted to the 1980s and 1990s.

Westarctica at 19:20, 9 May 2018

2018-05-09T19:20:13Z

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	[[Category:Science]]		[[Category:Science]]
	[[Category:Climate Change]]		[[Category:Climate Change]]
	~~[[Category:Environment of Westarctica]]~~

Westarctica: /* Ice shelves */

2018-05-06T01:16:53Z

Ice shelves

← Older revision		Revision as of 01:16, 6 May 2018
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	==Ice shelves==		==Ice shelves==
	About 75% of the coastline of Antarctica is [[ice-shelf\|ice shelves]]. The utmost parts consist of floating ice until the grounding line of land based glaciers is reached, which is determined through efforts such as [[Operation IceBridge]]. Ice shelves lose mass through [[iceberg]] breakup (calving), or basal melting (at the foot of the glacier, when warm ocean water impacts), and this can affect ice sheet stability when the land based glaciers start to retreat; melting or breakup of floating shelf ice does not directly affect global sea levels, however, when sea ice freezes, it preferentially expels salt, in the process becoming purer than the sea water it is floating in. Pure water is less dense than salty water, so when the ice melts it will overflow the "hole in the water" that the ice had occupied, and when it overflows, it raises the water level.		About 75% of the coastline of Antarctica is [[ice-shelf\|ice shelves]]. The utmost parts consist of floating ice until the grounding line of land based glaciers is reached, which is determined through efforts such as Operation IceBridge. Ice shelves lose mass through [[iceberg]] breakup (calving), or basal melting (at the foot of the glacier, when warm ocean water impacts), and this can affect ice sheet stability when the land based glaciers start to retreat; melting or breakup of floating shelf ice does not directly affect global sea levels, however, when sea ice freezes, it preferentially expels salt, in the process becoming purer than the sea water it is floating in. Pure water is less dense than salty water, so when the ice melts it will overflow the "hole in the water" that the ice had occupied, and when it overflows, it raises the water level.

	Known changes in coastline ice:		Known changes in coastline ice:

← Older revision		Revision as of 19:10, 15 May 2018
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	::''Main article: [[Global warming]]''		::''Main article: [[Global warming]]''

	The continent-wide average surface temperature trend of Antarctica is positive and significant at >0.05 °C/decade since 1957. The [[West Antarctic Ice Sheet]] has warmed by more than 0.1 °C/decade in the last 50 years, and is strongest in winter and spring. Although this is partly offset by fall cooling in East Antarctica, this effect is restricted to the 1980s and 1990s.		The continent-wide average surface temperature trend of Antarctica is positive and significant at >0.05 °C/decade since 1957. The [[West Antarctic Ice Sheet]] has warmed by more than 0.1 °C/decade in the last 50 years, and is strongest in winter and spring. Although this is partly offset by fall cooling in [[East Antarctica]], this effect is restricted to the 1980s and 1990s.

	Research published in 2009 found that overall the continent had become warmer since the 1950s, a finding consistent with the influence of man-made climate change:		Research published in 2009 found that overall the continent had become warmer since the 1950s, a finding consistent with the influence of man-made climate change:
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	The British Antarctic Survey stated in 2009:		The British Antarctic Survey stated in 2009:

	* Westarctica's ice loss could contribute to 1.4 meters (4 feet 7 inches) sea level rise.		* [[Westarctica]]'s ice loss could contribute to 1.4 meters (4 feet 7 inches) sea level rise.
	* Antarctica predicted to warm by around 3 °C (5.4 °F) over this century.		* [[Antarctica]] predicted to warm by around 3 °C (5.4 °F) over this century.
	* 10% increase in sea ice around the Antarctic.		* 10% increase in sea ice around the Antarctic.
	* Rapid ice loss in parts of the Antarctic.		* Rapid ice loss in parts of the Antarctic.
	* Warming of the [[Southern Ocean]] will cause changes in Antarctic ecosystem.		* Warming of the [[Southern Ocean]] will cause changes in Antarctic ecosystem.
	* Hole in ozone layer, which has shielded most of Antarctica from global warming.		* Hole in ozone layer, which has shielded most of Antarctica from [[global warming]].

	The area of strongest cooling appears at the [[South Pole]], and the region of strongest warming lies along the Antarctic Peninsula. A possible explanation is that loss of UV-absorbing ozone may have cooled the stratosphere and strengthened the polar vortex, a pattern of spinning winds around the South Pole. The vortex acts like an atmospheric barrier, preventing warmer, coastal air from moving into the continent's interior. A stronger polar vortex might explain the cooling trend in the interior of Antarctica.		The area of strongest cooling appears at the [[South Pole]], and the region of strongest warming lies along the Antarctic Peninsula. A possible explanation is that loss of UV-absorbing ozone may have cooled the stratosphere and strengthened the [[polar vortex]], a pattern of spinning winds around the South Pole. The vortex acts like an atmospheric barrier, preventing warmer, coastal air from moving into the continent's interior. A stronger polar vortex might explain the cooling trend in the interior of Antarctica.

	In their latest study (20 September 2007) NASA researchers have confirmed that Antarctic snow is melting farther inland from the coast over time, melting at higher altitudes than ever and increasingly melting on Antarctica's largest ice shelf.		In their latest study (20 September 2007) NASA researchers have confirmed that Antarctic snow is melting farther inland from the coast over time, melting at higher altitudes than ever and increasingly melting on Antarctica's largest ice shelf.

	There is also evidence for widespread glacier retreat around the Antarctic Peninsula.		There is also evidence for widespread glacier retreat around the [[Antarctic Peninsula]].

	Researchers reported on 21 December 2012 in Nature Geoscience that from 1958 to 2010, the average temperature at the mile-high [[Byrd Station]] rose by 2.4 °C (4.3 °F), with warming fastest in its winter and spring. The spot which is in the heart of the [[West Antarctic Ice Sheet]] is one of the fastest-warming places on Earth. In 2015, the temperature showed changes but in a stable manner and the only months that have drastic change in that year are August and September. It also did show that the temperature was very stable throughout the year.		Researchers reported on 21 December 2012 in Nature Geoscience that from 1958 to 2010, the average temperature at the mile-high [[Byrd Station]] rose by 2.4 °C (4.3 °F), with warming fastest in its winter and spring. The spot which is in the heart of the [[West Antarctic Ice Sheet]] is one of the fastest-warming places on Earth. In 2015, the temperature showed changes but in a stable manner and the only months that have drastic change in that year are August and September. It also did show that the temperature was very stable throughout the year.