Lincoln Sea: Difference between revisions

{{shortShortdescription|A partBodyofthe Arctic Ocean from Cape Columbia, Canada,waterin thewestArcticto Cape Morris Jesup, Greenland, in the eastOcean}}

'''Lincoln Sea''' ({{lang-langx|fr|Mer de Lincoln}}; {{lang-langx|da|Lincolnhavet}}) is a body of water in the [[Arctic Ocean]], stretching from [[Cape Columbia]], [[Canada]], in the west to [[Cape Morris Jesup]], [[Greenland]], in the east. The northern limit is defined as the [[great circle]] line between those two [[headland]]s. It is covered with [[sea ice]] throughout the year, the thickest sea ice in the Arctic Ocean, which can be up to {{convert|15|m|ft|abbr=on}} thick. Water depths range from {{convert|100|m|ft|abbr=on}} to {{convert|300|m|ft|abbr=on}}. Water and ice from Lincoln Sea empty into [[Robeson Channel]], the northernmost part of [[Nares Strait]], most of the time.

The sea was named after [[Robert Todd Lincoln]], then [[United States Secretary of War]], on [[Augustus Greely|Adolphus W. Greely]]'s 1881–1884 Arctic expedition into [[Lady Franklin Bay]].<ref>{{cite web|url=http:// deepseawaters /Lincoln_Sea.htm|title=Lincoln Sea, a sea in the Arctic Ocean|year=2012|publisher=deepseawaters, Phoenix, Arizona|accessdateaccess-date=17 July 2012}}</ref>

The Lincoln Sea has been found to contain water with three distinct properties. The first concerns the water in the inner part of the Lincoln Sea shelf, where the temperature and salinity profiles increase from the surface to the seafloor. The second involves the water covering the outer part of the shelf, including the slope; the waters here hold attributes similar to those in the Canadian basin and thus not unlike those from the Pacific. The third includes the waters north of theshelf’sshelf'sslope. These waters protrude into the Arcticbasin’sbasin'slarge-scale circulation, and so their characteristics appear to change over to those found in the Eurasian basin.

Along the continental margins of the Arctic Ocean basin, narrow [[boundary current]]s are hypothesized to house intense large-scale [[advection]] that is critical in the general circulation of Arctic waters. One of these boundary currents resides along the sloping edge of the Lincoln Sea shelf, between the base and the shelf break at approximately 1600 m. Thecurrent’scurrent'sstrength is 5–6 cm/s, according to long-term measurements. Assuming an undercurrent with an average strength of 4 cm/s and dimensions of 50 km in length and 1000 m in depth, the transport delivered over the slope of the Lincoln Sea shelf would be 2 [[Sverdrup]]s, where 1 Sverdrup equals 10^6 m^3/s. Measurements reveal that this undercurrent shares comparable features to that found in the [[Beaufort Sea]], whose boundary currents are responsible for large-scale advection within the Arctic circulation. Because of this mutual oceanographic behavior, it has been determined that the Lincoln Sea undercurrent continuously flows and is a component of the boundary current system that spans between [[Alaska]] and [[Greenland]] along the northern shores of the Canadian archipelago.<ref>{{cite journal|title=Boundary undercurrent and water mass changes in the Lincoln Sea|year=1997|doi=10.1029/96JC03441|bibcode=1997JGR...102.3393N|volume=102|issue=C2|journal=Journal of Geophysical Research: Oceans|pages=3393–3403|last1 = Newton|first1 = John L.|last2=Sotirin|first2=Barbara J.|doi-access=free}}</ref>

In May 2004 and 2005, [[electromagnetic radiation|electromagnetic]] measurements from helicopters revealed insights into the thickness of the [[sea ice]] in the Lincoln Sea and surrounding waters. With thicknesses ranging between 3.9 and 4.2 m, [[sea ice|multi-year ice]] dominates south of 84°N. [[sea ice|First-year ice]], with thicknesses ranging between 0.9 and 2.2 m, denotes the refreezing of the Lincoln Polynya ice. These helicopter measurements concur with satellite-based radar imagery as well as ground-based electromagnetic observations. Drifting buoys have exposed a southward drift of sea ice toward [[Ellesmere Island]] and [[Nares Strait]]. It has been concluded that [[shear (fluid)|shear]] in the Lincoln Sea narrow boundary current plays an important role in shifting and thus removing sea ice from the Arctic region.<ref>{{cite web|url=http://umd.library.ingentaconnect /content/igsoc/agl/2006/00000044/00000001/art00040|title=Comparison of the sea-ice thickness distribution in the Lincoln Sea and adjacent Arctic Ocean in 2004 and 2005|year=2006|publisher=International Glaciological Society|accessdateaccess-date=9 November 2013}}{{dead link|date=December 2017 |bot=InternetArchiveBot |fix-attempted=yes }}</ref>

The majority of sea ice export takes place on the eastern edges of the Arctic Ocean circulation near Greenland through the [[Fram Strait]]. Sea ice export through the Canadian archipelago was originally assumed to be zero, but that is not the case. The Lincoln Sea contains very thick multi-year sea ice, and so was thought to be stationary because of the apparent lack of oceanic outlets. However, according to a Canadian sea ice study, an area of approximately 22500 km² of multi-year sea ice is drained through the Nares Strait each year. During the [[Northern Hemisphere]] [[winter]], an area of about 225 km² of ice reforms, resulting in 335 km² of total sea ice drainage. Although this represents only one of the many pathways from the Arctic Ocean basin through the Canadian archipelago, "…this [total drainage] is an order of magnitude less than the [[flux]] of sea ice out of [the] Fram Strait." <ref>{{cite web|url=http://clic.npolar.no/reports/archive/iapo_inf_04.pdf#page=31|title=Drainage of multi-year sea ice from the Lincoln Sea|year=1998|publisher=World Climate Research Program|accessdateaccess-date=10 November 2013|archive-url=https://web.archive.org/web/20131111041846/http://clic.npolar.no/reports/archive/iapo_inf_04.pdf#page=31|archive-date=2013-11-11|deadurl-url=yes|dfstatus=dead}}</ref>

A disagreement over a 200-square-kilometre section of the Lincoln Sea emerged after 1973 when Canada and Denmark signed a treaty<ref>{{cite web|url=http:// international.gc.ca/media/aff/news-communiques/2012/11/28a.aspx|title=Canada and Kingdom of Denmark Reach Tentative Agreement on Lincoln Sea Boundary Backgrounder|year=2012|publisher=Foreign Affairs and International Trade Canada|accessdateaccess-date=16 February 2014|archive-url=https://web.archive.org/web/20140222235231/http:// international.gc.ca/media/aff/news-communiques/2012/11/28a.aspx|archive-date=22 February 2014|url-status=dead}}</ref> establishing the offshore boundary north of Canada's [[Ellesmere Island]] and [[Denmark|Danish]]-controlled [[Greenland]] but left portions of it undefined.

From Canada's point of view, the point of focus in the Lincoln Sea dispute has been Denmark's inclusion oftiny[[Beaumont Island(Greenland)]](not to be confused with [[Beaumont Island]] off the west coast of [[Graham Land]], [[Antarctica]]) off Greenland's northwest coast in calculating the boundary. The boundary is determined in that region by an "equidistance" principle that draws the line halfway between points along each country's coastline. Canada has basically argued thattheBeaumont"rock" poking out of the wavesIslandis too insignificant to be used by Greenland to help determine the international boundary.<ref>{{cite web|url=http://www2.canada /edmontonjournal/news/story.html?id=4dd58b3c-e40d-4767-b943-1b6da9572a70.pdf|title=Canada, Denmark start talks to resolve border dispute|year=2010|publisher=Edmonton Journal|accessdateaccess-date=19 June 2012|deadurlurl-status=yesdead|archiveurlarchive-url=https://web.archive.org/web/20130512221442/http://www2.canada /edmontonjournal/news/story.html?id=4dd58b3c-e40d-4767-b943-1b6da9572a70.pdf|archivedatearchive-date=12 May 2013|df=}}</ref>

The [[International Hydrographic Organization]] defines the limits of the Lincoln Sea as follows:<ref>{{cite web|url=httphttps://iho.int/iho_pubsuploads/standarduser/Spubs/standards/s-23/S-23_Ed3_1953_EN.pdf|title=Limits of Oceans and Seas, 3rd edition|year=1953|publisher=International Hydrographic Organization|accessdateaccess-date=28 December 2020|archive-url=https://web.archive.org/web/20111008191433/http:// iho-ohi.net/iho_pubs/standard/S-23/S23_1953.pdf|archive-date=68FebruaryOctober20102011}}</ref>

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