Climate of Antarctica#Precipitation

The highest temperature ever recorded on Antarctica was {{convert|19.8|C|F|1}} recorded at Signy Research Station, Signy Island on 30 January 1982.{{cite web |url=https://public-old.wmo.int/en/media/press-release/wmo-verifies-highest-temperatures-antarctic-region |archive-url=https://web.archive.org/web/20231218174524/https://public-old.wmo.int/en/media/press-release/wmo-verifies-highest-temperatures-antarctic-region |url-status=dead |archive-date=18 December 2023 |title=WMO verifies highest temperatures for Antarctic Region |date=1 March 2017 |access-date=12 July 2018 }}{{cite web |url=https://wmo.int/news/media-centre/wmo-verifies-one-temperature-record-antarctic-continent-and-rejects-another |title=WMO verifies one temperature record for Antarctic continent and rejects another |publisher=World Meteorological Organization |date=1 July 2021 |access-date=3 July 2021}}

The highest temperature on the Antarctic mainland was {{convert|18.3|C|F|1}} at the Esperanza Base (Argentina) on 6 February 2020.{{Cite web|publisher=The World Meteorological Organization (WMO)|url=https://wmo.int/news/media-centre/wmo-verifies-one-temperature-record-antarctic-continent-and-rejects-another|title=WMO verifies one temperature record for Antarctic continent and rejects another|date=2021-07-01|accessdate=2022-05-17}}

File:Five Myr Climate Change.svg and interglacial cycles of the present ice age]] The lowest air temperature record, the lowest reliably measured temperature on Antarctica was set on 21 July 1983, when a temperature of {{convert|−89.2|C}} was observed at Vostok Station.{{cite web|url=http://wmo.asu.edu/world-lowest-temperature|title=World: Lowest Temperature - ASU World Meteorological Organization|work=asu.edu|url-status=dead|archive-url=https://web.archive.org/web/20100616025722/http://wmo.asu.edu/world-lowest-temperature|archive-date=16 June 2010}} For comparison, this is {{convert|10.7|C-change|F-change}} colder than subliming dry ice (at sea level pressure). The elevation of the location is {{convert|3488|m|ft|abbr=off|sp=us}}.

Satellite measurements have identified even lower ground temperatures, with {{convert|−93.2|C}} having been observed at the cloud-free East Antarctic Plateau on 10 August 2010.[https://www.bbc.com/news/science-environment-25287806 Coldest spot on Earth identified by satellite] {{webarchive|url=https://web.archive.org/web/20160414013306/http://www.bbc.com/news/science-environment-25287806 |date=14 April 2016 }}, Jonathan Amos, BBC News, 9 December 2013.

The lowest recorded temperature of any location on Earth's surface at {{Coord|81.8|S|63.5|E|dim:10000km}} was revised with new data in 2018 in nearly 100 locations, ranging from {{convert|−93.2|C|F|1}}{{cite web|url=http://nsidc.org/news/press/2013_ColdestPlace_PR.html|title=Landsat 8 helps unveil the coldest place on Earth|publisher=National Snow and Ice Data Center|date=9 December 2013|author=Natasha Vizcarra|access-date=27 December 2013|url-status=live|archive-url=https://web.archive.org/web/20131220034754/http://nsidc.org/news/press/2013_ColdestPlace_PR.html|archive-date=20 December 2013}} to {{convert|−98|C|F|1}}.{{cite web |author=Natasha Vizcarra |date=25 May 2018 |title=New study explains Antarctica's coldest temperatures |url=https://nsidc.org/news-analyses/news-stories/new-study-explains-antarcticas-coldest-temperatures |url-status=live |archive-url=https://web.archive.org/web/20241217210227/https://nsidc.org/news-analyses/news-stories/new-study-explains-antarcticas-coldest-temperatures |archive-date=17 December 2024 |access-date=22 January 2025 |publisher=The National Snow and Ice Data Center (NSIDC)}} This unnamed part of the Antarctic plateau, between Dome A and Dome F, was measured on 10 August 2010, and the temperature was deduced from radiance measured by the Landsat 8 and other satellites. It was discovered during a National Snow and Ice Data Center review of stored data in December 2013{{cite web|url=https://www.bbc.co.uk/news/science-environment-25287806|title=Coldest spot on Earth identified by satellite|publisher=BBC News Science & Environment|date=9 December 2013|author=Jonathan Amos|access-date=27 December 2013|url-status=live|archive-url=https://web.archive.org/web/20131226192112/http://www.bbc.co.uk/news/science-environment-25287806|archive-date=26 December 2013}} but revised by researchers on 25 June 2018.{{cite web|url=https://nsidc.org/sites/nsidc.org/files/files/Scambos_et_al-2018-Geophysical_Research_Letters.pdf|publisher=The National Snow and Ice Data Center (NSIDC)|date=25 May 2018|author=Ted Scambos|title=Scambros et al 2018}}{{cite web|url=https://www.bbc.co.uk/helpandfeedback/corrections_clarifications.html|title=BBC Corrections and Clarifications page|author=NOT CORRECTED|access-date=7 August 2018|archive-date=13 October 2018|archive-url=https://web.archive.org/web/20181013082606/https://www.bbc.co.uk/helpandfeedback/corrections_clarifications.html|url-status=dead}} This temperature is not directly comparable to the {{convert|-89.2|C|F|1}} reading quoted above, since it is a skin temperature deduced from satellite-measured upwelling radiance, rather than a thermometer-measured temperature of the air {{convert|1.5|m|ft|0|abbr=on}} above the ground surface.

The mean annual temperature of the interior is {{convert|-43.5|C|F|1}}.{{cite web|url=https://climatereanalyzer.org/reanalysis/monthly_tseries/|publisher=Climate Change Institute, University of Maine|access-date=18 May 2023|title=Annual mean 2m Temperature for 0-150ºE, 75-90ºS, Climate Reanalyzer}} The coast is warmer; on the coast Antarctic average temperatures are around {{convert|-10|C|F|1}} (in the warmest parts of Antarctica) and in the elevated inland they average about {{convert|-55|C|F|1}} in Vostok.{{cite web|url=http://www.antarctica.gov.au/about-antarctica/environment/weather|title=Antarctic weather|

website=www.antarctica.gov.au|url-status=live|archive-url=https://web.archive.org/web/20161105034626/http://www.antarctica.gov.au/about-antarctica/environment/weather|archive-date=5 November 2016}}{{cite web |url=http://www.aari.aq/data/data.asp?lang=0&station=6 |title=Antarctic climatic data |

access-date=7 May 2008 |url-status=dead |archive-url=https://web.archive.org/web/20080507070713/http://www.aari.aq/data/data.asp?lang=0&station=6 |archive-date=7 May 2008 }}

Monthly means at McMurdo Station range from {{convert|-26|C|F|1}} in August to {{convert|-3|C|F|1}} in January.{{cite web|url=http://www.coolantarctica.com/Antarctica%20fact%20file/antarctica%20environment/climate_graph/vostok_south_pole_mcmurdo.htm|title=Antarctica Climate data and graphs, South Pole, McMurdo and Vostok|work=coolantarctica.com|url-status=dead|archive-url=https://web.archive.org/web/20101009114203/http://coolantarctica.com/Antarctica%20fact%20file/antarctica%20environment/climate_graph/vostok_south_pole_mcmurdo.htm|archive-date=9 October 2010|access-date=14 May 2014}}

At the South Pole, the highest temperature ever recorded was {{convert|-12.3|C|F|1}} on 25 December 2011.{{cite web|url=http://amrc.ssec.wisc.edu/blog/2011/12/28/preliminary-report-record-temperatures-at-south-pole-and-nearby-aws-sites/|title=Preliminary Report: Record Temperatures at South Pole (and nearby AWS sites…)|date=28 December 2011|author=Matthew A. Lazzara|access-date=28 December 2011|url-status=live|archive-url=http://archive.wikiwix.com/cache/20111230104839/http://amrc.ssec.wisc.edu/blog/2011/12/28/preliminary-report-record-temperatures-at-south-pole-and-nearby-aws-sites/|archive-date=30 December 2011}} Along the Antarctic Peninsula, temperatures as high as {{convert|18.3|C|F|1}} have been recorded,{{clarify | reason = Relationship between this statement and the earlier statement about the highest temperature ever recorded in Antarctica is unclear.|date=December 2013}} though the summer temperature is below {{convert|0|C|F}} most of the time. Severe low temperatures vary with latitude, elevation, and distance from the ocean. East Antarctica is colder than West Antarctica because of its higher elevation.{{citation needed|date=January 2014}} The Antarctic Peninsula has the most moderate climate. Higher temperatures occur in January along the coast and average slightly below freezing.

File:File-Dgv-surfbal-1.gif on Antarctica (mm liquid equivalent)]]

The total precipitation on Antarctica, averaged over the entire continent, is about {{convert|166|mm|abbr=off}} per year (Vaughan et al., J. Clim., 1999). The actual rates vary widely, from high values over the Peninsula ({{convert|380 to 640|mm|abbr=off}} a year) to very low values (as little as {{convert|50|mm|abbr=off}} in the high interior (Bromwich, Reviews of Geophysics, 1988). Areas that receive less than {{convert|250|mm|abbr=off}} of precipitation per year are classified as deserts. Almost all Antarctic precipitation falls as snow.{{cite web|archive-url=https://web.archive.org/web/20161113152357/http://www.dna.gov.ar/la-ant%C3%A1rtida |archive-date=13 November 2016 |url=http://www.dna.gov.ar/la-ant%C3%A1rtida |title=La Antártida |publisher=Dirección Nacional del Antártico |language=es |access-date=13 November 2016 |url-status=dead }} Rainfall is rare and mainly occurs during the summer in coastal areas and surrounding islands. Note that the quoted precipitation is a measure of its equivalence to water, rather than being the actual depth of snow. The air in Antarctica is also very dry. The low temperatures result in a very low absolute humidity, which means that dry skin and cracked lips are a continual problem for scientists and expeditioners working on the continent.{{cite news|newspaper=Fair Observer|title=Is Mainstream Tourism a Good Way to Save Helpless Antarctica? |url=https://www.fairobserver.com/world-news/is-mainstream-tourism-a-good-way-to-save-helpless-antarctica/ |access-date=9 July 2024}}

{{Main|Antarctica Weather Danger Classification}}

The weather in Antarctica can be highly variable, and the weather conditions can often change dramatically in short periods of time. There are various classifications for describing weather conditions in Antarctica; restrictions given to workers during the different conditions vary by station and nation.{{cite web|url=http://antarcticsun.usap.gov/pastIssues/1997-1998/1997_10_18.pdf |title=Weathering The Conditions |work=The Antarctic Sun |date=18 October 1997 |access-date=8 June 2015 |pages=8 |url-status=live |archive-url=http://archive.wikiwix.com/cache/20150609102338/http://antarcticsun.usap.gov/pastIssues/1997-1998/1997_10_18.pdf |archive-date=9 June 2015}}{{cite web |url=https://www.nsf.gov/about/contracting/rfqs/support_ant/docs/mcmurdo_guide2006.pdf |title=Weather and Travel |publisher=McMurdo Station |work=Welcome to McMurdo Station |access-date=8 June 2015 |author=Jim Scott |pages=6 |url-status=dead |archive-url=https://web.archive.org/web/20140910200435/http://www.nsf.gov/about/contracting/rfqs/support_ant/docs/mcmurdo_guide2006.pdf |archive-date=10 September 2014 }}{{cite web|url=http://antarcticanz.govt.nz/images/downloads/publications/FieldHandbookA6Aug12.pdf |title=Field Manual |publisher=New Zealand Government |work=Antarctica New Zealand |access-date=8 June 2015 |pages=37 |url-status=dead |archive-url=https://web.archive.org/web/20150115054010/http://antarcticanz.govt.nz/images/downloads/publications/FieldHandbookA6Aug12.pdf |archive-date=15 January 2015}}

Nearly all of Antarctica is covered by a sheet of ice that is, on average, at least {{convert|1500|m|ft|sigfig=1|abbr=on}} thick. 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 {{convert|30|e6km3|e6cumi|abbr=on}} of ice—the seas would rise by over {{convert|60|m|ft|abbr=on}}.{{cite web|url=http://www.grida.no/climate/ipcc_tar/wg1/412.htm#tab113|title=Climate Change 2001: The Scientific Basis|publisher=Grida.no|access-date=27 March 2011|url-status=dead|archive-url=https://web.archive.org/web/20071216235037/http://www.grida.no/climate/ipcc_tar/wg1/412.htm#tab113|archive-date=16 December 2007}} 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 precipitation, which takes the form of snow. This would increase the amount of ice in Antarctica, offsetting approximately one third of the expected sea level rise from thermal expansion of the oceans.{{cite web|url=http://www.grida.no/climate/ipcc_tar/wg1/428.htm|title=Climate Change 2001: The Scientific Basis|publisher=Grida.no|access-date=27 March 2011|url-status=dead|archive-url=https://web.archive.org/web/20110514002354/http://www.grida.no/climate/ipcc_tar/wg1/428.htm|archive-date=14 May 2011}}

During a recent{{when|date=February 2020}} decade, East Antarctica thickened at an average rate of about {{convert|1.8|cm|in|frac=16|abbr=on}} per year while West Antarctica showed an overall thinning of {{convert|0.9|cm|in|frac=16|abbr=on}} per year.{{cite journal|vauthors=Davis CH, Li Y, McConnell JR, Frey MM, Hanna E |s2cid=31797055 |year=2005 |title=Snowfall-Driven Growth in East Antarctic Ice Sheet Mitigates Recent Sea-Level Rise |journal=Science |volume=308 |issue=5730 |pages=1898–1901 |doi=10.1126/science.1110662 |bibcode=2005Sci...308.1898D |pmid=15905362|doi-access=free }} For the contribution of Antarctica to present and future sea level change, see sea level rise. Because ice flows, albeit slowly, the ice within the ice sheet is younger than the age of the sheet itself.

{{notelist-ua|refs={{efn-ua|name=ice-volume-rounding|text=The total ice volume is different from the sum of the component parts because individual figures have been rounded.}}}}

File:Antarctica ice shelves-en.svg

About 75% of the coastline of Antarctica is ice shelf. The majority of ice shelf consists of floating ice, and a lesser amount consists of glaciers that move slowly from the land mass into the sea. Ice shelves lose mass through breakup of glacial ice (calving), or basal melting due to warm ocean water under the ice.{{cite journal|journal=Science |title=Ice-Shelf Melting Around Antarctica |author1=E. Rignot |author2=S. Jacobs |author3=J. Mouginot |author4=B. Scheuchl |doi=10.1126/science.1235798 |bibcode=2013Sci...341..266R |volume=341 |issue=6143 |pages=266–270 |pmid=23765278 |year=2013|s2cid=206548095 |doi-access=free }}

Melting or breakup of floating shelf ice does not directly affect global sea levels; however, ice shelves have a buttressing effect on the ice flow behind them. If ice shelves break up, the ice flow behind them may accelerate, resulting in increasing melt of the Antarctic ice sheet and an increasing contribution to sea level rise.

Known changes in coastline ice around the Antarctic Peninsula:

• 1936–1989: Wordie Ice Shelf significantly reduced in size.
• 1995: Ice in the Prince Gustav Channel disintegrated.
• Parts of the Larsen Ice Shelf broke up in recent decades.
• 1995: The Larsen A ice shelf disintegrated in January 1995.
• 2001: {{convert|3,250|km2|sqmi|abbr=on}} of the Larsen B ice shelf disintegrated in February 2001. It had been gradually retreating before the breakup event.
• 2015: A study concluded that the remaining Larsen B ice-shelf will disintegrate by the end of the decade, based on observations of faster flow and rapid thinning of glaciers in the area.{{cite web|title=NASA Study Shows Antarctica's Larsen B Ice Shelf Nearing Its Final Act|url=http://www.nasa.gov/press-release/nasa-study-shows-antarctica-s-larsen-b-ice-shelf-nearing-its-final-act|author=NASA|date=14 May 2015|url-status=live|archive-url=https://web.archive.org/web/20150609032810/http://www.nasa.gov/press-release/nasa-study-shows-antarctica-s-larsen-b-ice-shelf-nearing-its-final-act/|archive-date=9 June 2015}}

The George VI Ice Shelf, which may be on the brink of instability,{{cite web|url=http://www.antarctica.ac.uk/BAS_Science/Highlights/2001/george_vi.html |title=Millennial-scale variability of George VI Ice Shelf, Antarctic Peninsula |publisher=Natural Environment Research Council |access-date=8 June 2015 |first1=Mike |last1=Bentley |first2=Dominic |last2=Hodgson |archive-url=https://web.archive.org/web/20020912045816/http://www.antarctica.ac.uk/BAS_Science/Highlights/2001/george_vi.html |archive-date=12 September 2002}} has probably existed for approximately 8,000 years, after melting 1,500 years earlier.{{cite web|url=http://igloo.gsfc.nasa.gov/wais/pastmeetings/abstracts00/Bentley2.htm |title=Holocene Instability of the George VI Ice Shelf, Antarctic Peninsula |access-date=8 June 2015 |last1=Bentley|first1= M.J.|last2= Hjort|first2= C. |last3=Ingolfsson|first3= O. |last4=Sugden|first4= D.E.|url-status=dead |archive-url=https://web.archive.org/web/20041020150823/http://igloo.gsfc.nasa.gov/wais/pastmeetings/abstracts00/Bentley2.htm | archive-date=20 October 2004}} Warm ocean currents may have been the cause of the melting.{{cite web|url=http://www.antarctica.ac.uk/News_and_Information/Press_Releases/story.php?id=160 |title=Press Release – New Year's Honours for British Antarctic Survey Personnel |publisher=British Antarctic Survey |date=5 January 2006 |url-status=dead |archive-url=https://web.archive.org/web/20061215053832/http://www.antarctica.ac.uk/News_and_Information/Press_Releases/story.php?id=160 |archive-date=15 December 2006}} Not only are the ice sheets losing mass, they are losing mass at an accelerating rate.{{cite web|url=https://www.nasa.gov/topics/earth/features/20100108_Is_Antarctica_Melting.html |title=NASA - Is Antarctica Melting? |website=www.nasa.gov |url-status=live |archive-url=https://web.archive.org/web/20161212153658/https://www.nasa.gov/topics/earth/features/20100108_Is_Antarctica_Melting.html |archive-date=12 December 2016}}

{{Excerpt|Climate change in Antarctica|file=no|paragraphs=1,2}}

• Antarctic oscillation
• Antarctica cooling controversy
• Climate of the Arctic
• Effects of global warming
• Polar amplification
• Retreat of glaciers since 1850
• Southern Ocean

Notes

{{reflist|30em}}

Sources

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{{main|Bibliography of Antarctica}}

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• [http://www.antarctica.ac.uk/met/READER/ Temperature data from the READER project]
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• [https://www.usatoday.com/story/tech/sciencefair/2012/12/23/antarctica-warming-global/1782829/ Western Antarctica warming confirmed] 23 December 2012 USA Today
• [https://www.youtube.com/watch?v=03t3429OUSM NASA experts explain ice melt in Antarctica (2014)]

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{{Antarctica}}

Category:Environment of Antarctica