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).

 

Kansan

The American name for the glacial period starting about 620,000 years ago and lasting for about 60,000 years. Northern and Central Europe and North America had extensive ice cover and the Arctic Ocean had ice. Two stadials are recognized in this period, which is called the Mindel period in the Alpine and the Elster period in the Scandinavian classification scheme. The was preceded by the Nebraskan period and followed by the Saale period.

 

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. Its area is about 883,000 km and its volume 104,000 km . It is located entirely on the continental shelf and has an average depth of 118 m, although it reaches over 600 m depth in one limited trench. The seafloor is chiefly a series of platforms or broad terraces stepping downward from the southeast to the north and west. See Zenkevitch (1963) and Fairbridge (1966).

 

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.

 

katallobaric wave

A center of 24-hour pressure fall that moves toward the Antilles from the Cape Verde region with a frequency of about one every three or four days during hurricane season in the Atlantic Ocean. These are apparently incipient tropical storms. See Byers (1944).

 

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).

 

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 N and 128 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

The SI unit of thermodynamic temperature. It is defined as 1/273.16 of the temperature of the triple point of water above absolute zero. The symbol for this is K.

 

Kelvin thermodynamic scale of temperature

A scale of temperature based on the thermodynamic principle of the performance of a reversible heat engine. This scale cannot have negative values so absolute zero is a well-defined thermodynamic temperature. The temperature interval used in this system is the kelvin.

 

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 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.

 

Kerhallet, C.P. de

See Peterson et al. (1996), p. 76.

 

keystone species

The concept that only one or a few species have uniquely important effects of the community or ecosystem by virtue of unique traits or attributes. The removal of a keystone species, like the removal of a keystone from an arch, results in dramatic changes in the functional properties of the ecological system, e.g. changes in diversity, abundance or habitat structure. See Heywood (1995).

 

khamsin

A southerly wind blowing over Egypt in front of depressions passing eastwards along the Mediterranean or North Africa, while pressure is high east of the Nile. The wind, most frequent from April to June, blows hotly and dryly from the interior of the continent and often carries much dust. According to the locals it blows for a period of fifty days, with khamsin being the Arabic word for fifty. This term is also loosely applied to any hot, dry winds from the south or southwest in the Red Sea. This corresponds to the scirocco of North Africa.

 

Kibel number

See Rossby number.

 

Kimmeridgian

The second of three ages in the Late Jurassic epoch, lasting from 156 to 152 Ma. It is preceded by the Oxfordian age and followed by the Tithonian age.

 

Kirchhoff's law

In radiation transfer, a law stating that in thermodynamic equilibrium and at a given wavelength the ratio of the intensity of emission to the absorptivity of any substance does not depend on the nature of the substance but rather only on the temperature and the wavelength, i.e.

Another way of saying this is the the absorptivity and emissivity of a substance are equal and any single wavelength.

 

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).