Ka-Km

Kamchatka Current

One of two currents (the other being the Alaskan Stream) in the northwest Pacific that combine to form the Oyashio Current. The Kamchatka brings water southward from the Bering Sea, where it is associated with the quasi-permanent anticyclonic eddies found close the the western shore. These eddies are caused by bottom topography and coastline configuration and result in countercurrents along the coast. See Tomczak and Godfrey (1994).

Kara Sea

One of the seas found on the Siberian shelf in the Arctic Mediterranan Sea. It is located between the Barents Sea to the west and the Laptev Sea to the east, and adjoins the Arctic Ocean proper to the north. The western boundary is defined by a line connecting the Kol'zat Cape with the Zhelaniya Cape at Novaya Zemlya. This boundary passes along the eastern shores of Novaya Zemlya and Vaigach Island, crossing the Matochkin Shar, Kara Gate and Yugorsky Shar Straits. The Kara Gate Strait is 45 km wide, 33 km long and up to 119 m deep. The other two straits are narrow than 2.5 km and shallower than 36 m. The Kara Sea is separated from the Laptev Sea by the Northern Land Archipelago and the Shokal'sky and Vil'kitsky Straits, with the boundary passing along the eastern periphery of these straits. The Vil'kitsky Strait is about 130 km long, has a minimum width of 56 kim and depths reaching 210 m. The Shokal'sky Strait is 110 km in length, has a minimum width of 20 km, and a depth of 200-250 m. The northern boundary proceeds from Kol'zat Cape to the Arktichesky Cape (in the Northern land), and the southern boundary is along the mainland coast.

Its area is about 883,000 km$^2$ and its volume 98,000 km$^3$. Over 80% of the area and 77% of the volume constitutes a shelf zone with depths less than 200 m. The mean depth is 111 m and the maximum 620 m (located in the northern section at about 80$^\circ$ N and 71$^\circ$ E). The seafloor is chiefly a series of platforms or broad terraces stepping downward from the southeast to the north and west. The most prominent features are the St. Anna (up to 610 m deep) and Voronin (up to 450 m deep) troughs. Between these is the Central Kara plain with depths less than 50 m. Along the Novaya Zemlya coast is the Novozemel'sky depression reaching depths greater than 400 m.

Zenkevitch (1963) gives the history of the exploration of the Kara Sea to 1955:

The first data on the Kara Sea were collected by the Swedish expeditions of O. Nordenskjöld in 1975 (in the Pröven), in 1876 (in the Imer) and in 1878 (in the Vega). In 1882 and 1883 biological work was carried out there by a Dutch expedition in the Varna and by a Danish one in the Dymphna. In 1893 the Kara Sea was surveyed by Nansen's famous Fram, in 1900 by Toll's Russian expedition in the Zarya, in 1907 by the expedition of the Duke of Orleans in the Belgica and in 1918 by R. Amundsen in the Mod. All these expeditions have contributed to the study of the Kara Sea fauna.

A comprehensive study of the Kara Sea and its fauna was begun as recently as 1921 by the expedition of the Oceanographic Institute in the Malygin and by that of the Hydrographic Directorate in the Taimyr. In subsequent years a number of Soviet expeditions of the Arctic Institute and the Committee of the Northern Sea Route cruised in the Kara Sea. Among them the voyages of the Sedov (1929, 1930 and 194), Lomonosov (1931), Rusanov (1931 and 1932) and others, and particularly the expeditions of the Sadko (1936, 1936 and 1937) which sailed to the north of the Kara Sea far into the Arctic basin and which was the first to haul bottom fauna from depths of almost 4,000 m, are of especial interest. The results of the expedition of the trawler Maxim Gorky in 1945 were of importance. During the Soviet period the number of expeditions working in the Kara Sea has been more than doubled in comparison with those of all previous years.

A significant feature of the Kara Sea is the large input of freshwater from rivers. The total volume is about 1525 km$^3$ yr$^{-1}$ and is chiefly from the Ob (400 km$^3$ yr$^{-1}$), the Pur (30 km$^3$ yr$^{-1}$), the Taz (34 km$^3$ yr$^{-1}$), the Yenisey (630 km$^3$ yr$^{-1}$) and the Pyasina (50 km$^3$ yr$^{-1}$). The water masses are controlled by this contintal runoff as well as by water inflows from the Arctic Basin and Barents Sea. In the southwest, bottom water forms from winter cooling and increased salinity from ice growth. Above this are saline Barents Sea water (-1.90-6.00$^\circ$ C, 35.30-35.60) and Arctic surface water (-1.80$^\circ$ C, 32.00). In the north deep Atlantic water penetrates into the Kara Sea from the Arctic Basin via the St. Anna and Voronin troughs. On top of this are the Arctic surface water and, below that, the winter Kara Sea surface water (-1.40$^\circ$ C, 22.00-25.00).

The general circulation is influenced by the relative strengths of the Arctic High and Icelandic Low. When the former prevails, water masses are transported from south to north, river outflow increases, the inflow of Barents Sea water decreases. These combine to reduce surface water salinity, increase sea level, thicken the surface layer, and position the Atlantic water nearer to the surface layer. When the Icelandic Low is prevalent, water masses are transported from west to east, Barents Sea inflows increase, Kara Sea outflows to the Arctic surface water increase, the sea level and and the surface water layer both decrease, and the depth of the Atlantic water increases. See Zenkevitch (1963), Fairbridge (1966), Pavlov and Pfirman (1995), Pfirman et al. (1995) and Johnson et al. (2000).

[http://www.nadn.navy.mil/Oceanography/courses/SO426/atlas_summer/html/intro/intro_ks.htm]

katabatic wind

A phenomenon that originates with a layer of cold air forming near the ground on a night with clear skies and a low pressure gradient. If the ground is sloping, the air close to the ground is colder than air at the same level but at some horizontal distance. The result is downslope gravitational flow of the colder, denser air beneath the warmer, lighter air. This occurs on the largest scale as the outflowing winds from Greenland and Antarctica. Contrast with anabatic wind.

Kattegat

A sedimentary basin that provides part of the connection (along with Skagerrak) between the North Sea and the Baltic Sea. It is surrounded by Denmark to the southeast and southwest (with the connections to the Baltic in the former direction), Sweden to the northeast, and Skagerrak to the northwest. It is a shallow basin with a maximum depth of about 50 m in the southeastern part.

The circulation consists of two northwestward flowing surface currents originating from the two passages providing connections to the Baltic, one on either side of the basin, and a southeastward flowing countercurrent to the west of the eastern current that flows along the Swedish coast. The flow from the two northwestward currents, jointly called the Baltic Current, eventually combines and joins the North Jutland Current (NJC) as it turns around and becomes the Norwegian Coastal Current. The countercurrent originates as part of the NJC turning and flowing southeast. See Svansson (1975) and Danielssen et al. (1997).

Kau Bay

A bay formed by the two northern arms of the island of Halmahera in the Australasian Mediterranean Sea. It is located at about 1$^\circ$ N and 128$^\circ$ W and is considered part of the Halmahera Sea. It is composed of an inner basin 500 m deep separated from the outer depression by a shallow sill ranging from 40-50 m in depth. The shallow sill results in oxygen concentrations within the bay decreasing with depth until they reach zero below 400 m, with hydrogen sulfide becoming important near the bottom. See Fairbridge (1966).

Kelvin-Helmholtz instability

See ocean turbulence.

Kelvin wave

A type of coastally trapped wave motion where the velocity normal to the coast vanishes everywhere. The wave is nondispersive and propagates parallel to the shore with the speed of shallow water gravity waves, i.e. sqrt (gH). The profile perpendicular to shore either decays or grows exponentially seaward depending on whether the wave propagates with the coast to its right or left (in the northern hemisphere). For vanishing rotation, the decay or growth scale becomes infinite and the Kelvin wave reduces to an ordinary gravity wave propagating parallel to the coast. The dynamics of a Kelvin wave are such that it is exactly a linearized shallow water gravity wave in the longshore direction and exactly geostrophic in the cross-shore direction.

KERE

Acronym for Kuroshio Extension Region Experiment, a field investigation of the Kuroshio and the deep western boundary current east of Japan.

Kerguelan Plateau

A ridge located at approximately 75$^\circ$ E in the Southern Ocean that impedes the flow of the Antarctic Circumpolar Current at depths below 2000 m. Most of this broad plateau is between 2000 and 3000 m deep with some flow occurring below 3000 m in a narrow gap between itself and Antarctica.

KESS

Acronym for Kuroshio Extension System Study, a study designed to investigate the Kuroshio Extension System from 2001 to 2005. The goal is to understand the mechanisms that govern the Kuroshio Extension and associated recirculation gyre variability, and to identify the processes responsible for interannual variations in upper-ocean heat content and SST in the region. The objectives of KESS are:

• to demonstrate the capability of tomographic techniques in monitoring the variabiity of the 1000 km scale 3-D oceanic structures; and
• to obtain information about the acoustic environment for the design of the tomography array.

KESS will deploy eight reciprocal tomography moorings in the Kuroshio Extension (centered on 35$^\circ$N, 150$^\circ$W) for four years to study the climatological relevance of the Kuroshio Extension/mode water variability.

Kerhallet, C.P. de

See Peterson et al. (1996), p. 76.

Kibel number

See Rossby number.

Kircher, Athanasius (1602-1680)

A Jesuit priest who published the earliest chart of the global ocean circulation in 1664/1665 in an encyclopedia entitled Mundus Subterraneus. This chart reflected Kircher's concurrence with Aristotle's primum mobile theory in that the Pacific and Indian Oceans were shown as regions of broad westward flow. The Atlantic Ocean, being much better known at the time, was more detailed. It was shown with a closed subtropical gyre in the South Atlantic whose flow split near the equator off the coast of Brazil. The northward flowing branch continued along South America and on into the Gulf of Mexico, there flowing in a clockwise gyre around the edge of the Gulf and turning northward after reaching and rounding the tip of Florida. This flow joined with other waters moving north and northeast through the North Atlantic and on into the region north of Scandinavia.

It was at this point that Kircher launched into the realms of sheer speculation. The broad north Atlantic flow into the northern regions was supposed to be drawn into the earth's interior at the north pole and released at the south pole, with the process occurring rhythmically to additionally offer an explanation for the periodicity of the tides. He also included small spotlike features on the map that were supposed to be locations of whirlpools and entrances to a vast system of subterranean channels, one example being an entrance/exit pair on either side of Panama to facilitate the postulated broad western flow pattern. See Peterson et al. (1996).