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Lincoln Sea 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 headlands. It is covered with sea ice throughout the year, the thickest sea ice in the Arctic Ocean, which can be up to thick. Water depths range from to . 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 Adolphus W. Greely's 1881–1884 Arctic expedition into Lady Franklin Bay. Alert, the northernmost station of Canada, is the only populated place on the shore of Lincoln Sea. The body of water to the east of Lincoln Sea (east of Cape Morris Jesup) is Wandel Sea. ==Currents and Oceanic Circulation== Because of the severe ice conditions that last year-round, oceanographic measurements of the Lincoln Sea have been all but impossible. Before the 1980s, only low-flying aircraft samplings and ground observations from ice islands could be attempted; these did not stray far from the shores of Greenland and the Canadian Arctic Archipelago due to the harsh environment. Between 1989 and 1994, the field experiments in Project Spinnaker were underway, implementing instrumentation that captured temperature and salinity profiles well into the heart of the Lincoln Sea. Taken just east of where the North American continent intersects the Lomonosov Ridge, these observations revealed the oceanographic features and current formations within and surrounding the Lincoln Sea. Along the continental margins of the Arctic Ocean basin, narrow boundary currents are hypothesized to house intense large-scale advection that is critical in the general circulation of Arctic waters. From the Bering Strait, Pacific Ocean waters flow counterclockwise (cyclonically) along the northern shores of Canada, passing through the Lincoln Sea. Atlantic Ocean waters cyclonically flow in from and return to the Eurasian basin along the Greenland Sea continental slope. The waters of these basins converge at the Lincoln Sea, creating unique vertical temperature and salinity profiles here. Measurements detail that both the Pacific and Eurasian Ocean water profiles are clearly offset from one another, an important facet of the hydrography of the Lincoln Sea. 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 the shelf’s slope. These waters protrude into the Arctic basin’s large-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 currents 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. The current’s strength 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 Sverdrups, 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. 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Lincoln Sea」の詳細全文を読む スポンサード リンク
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