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caballing
See cabbeling.

cabbeling
In physical oceanography, a phenomenon that occurs when two water masses with identical densities but different temperatures and salinities mix to form a third water mass with a greater density than either of its constituents. This is hypothesized to be a major cause of sinking in high northern latitudes. See McDougall (1987b).

cabbeling coefficient
A quantity given by

$\displaystyle d\,=\,{1\over\beta}{ {\partial\beta} \over {\partial\theta} }\,-\... ... \over {\partial S} }\,-\, {1\over\beta}{ {\partial\alpha} \over {\partial S} }$

where $ \beta$ is the saline contraction coefficient, $ \alpha$ is the thermal expansion coefficient, $ \theta$ is the potential temperature, and $ S$ is the salinity. This describes changes of the isopycnal slope along isopycnals. See Muller (1995).

CABEX
Acronym for Cascadia Basin Experiments, an underwater acoustics experiment performed jointly by the APL at the University of Washington School of Oceanography and the Acoustical Oceanography Research Group at the IOS. In this experiment acoustic arrays are designed to record images of sea surface zone backscattering in order to distinguish between rough surface scattering and scattering from bubble distributions near and beneath the surface. The hypothesis being tested is whether the small void fraction bubble clouds are responsible for the observed increase over simple rough surface backscattering predictions at moderate to high wind speeds. See the CABEX Web site.

calcareous
Of or containing calcium carbonate or another, usually insoluble, calcium salt.

calcareous ooze
A fine-grained, deep-sea deposit of pelagic origin containing more than 30% calcium carbonate derived from the skeletal material of various plankton. It is the most extensive deposit on the ocean floor but restricted to depths less than about 3500 m due to the carbon compensation depth.

CALCOFI
Acronym for California Co-operative Fisheries Investigations.

[http://www-mlrg.ucsd.edu/calcofi/]
[http://www.sio.ucsd.edu/explorations/calcofi/]

CalCOOS
Acronym for the California Coastal Ocean Observation System, the mission of which is to provide an observation-based description of the resources of California's coastal ocean in support of science, coastal resource management and emergency response.

[http://www.calcoos.org/]

California Current
The eastern limb of the clockwise flowing subtropical gyre in the North Pacific. The California Current flows equatorward throughout the year offshore from California from the shelf break to about 1000 km from the coast. The current is strongest at the surface and extends over the upper 500 m of the water column, with seasonal mean speeds of about 10 cm s$ ^{-1}$. It carries relatively colder fresher subarctic water equatorward. Within about 300 km of the coast, some of the fresher water in the upper 20 m is associated with the Columbia River plume. South of Point Conception a portion of the Current turns southeastward and then shoreward and poleward. This is known as the Southern California Countercurrent (SCCC) during times when the flow successfully rounds the Point, and as the Southern California Eddy when the flow recirculates within the Bight.

From April until September northerly winds prevail which leads to upwelling and equatorward surface flow through the spring and summer months. This leads to an extremely large temperature gradient between a few kilometers offshore and the land surface with concomitant condensation and the sort of heavy fogs for which San Francisco is notorious. See Hickey (1979), Hickey (1993), Tomczak and Godfrey (1994) and Hickey (1998).

California Undercurrent
One of the two narrow, poleward-flowing boundary currents in the California Current system (the other being the Inshore Countercurrent). The CU appears as a subsurface maximum of flow between 100 and 250 m deep over the continental slope and transports warm, saline equatorial waters. It flows within 150 km of the coast as opposed to the 850-900 km extent of the southward flowing CC. The flow seems to be continuous for distances of 400 km or more, and has been observed at locations ranging from Baja California to Vancouver Island. Current measurements off Central California indicate continuous, year-round flow over the upper slope at around 350 m with an average speed of 7.6 cm s$ ^{-1}$. See Collins et al. (2000).

CALK
Acronym for Carbonate ALKalinity, a function of carbonate and bicarbonate ion concentration.

CAMBIOS
A French program to monitor the Azores front and the flow of meddy across that region. This is to be done via acoustic tomography using three sound transceivers as well as with a series of CTD/ADCP stations and some XBT deployments. See the CAMBIOS Web site.

Camotes Sea
A small sea within the Visayan Islands that comprise the middle portion of the Philippines. It is centered at about 124.5$ ^\circ$ E and 10.5$ ^\circ$ N and is connected to the Visayan Sea to the northwest (between the islands of Cebu and Leyte), and to the Bohol Sea to the south via the Tanon Strait and a passage between the islands of Bohol and Leyte. The Camotes Islands are prominently features in the midst of this sea.

Canadian Arctic Archipelago
See Collin and Dunbar (1964).

Canadian Basin Deep Water (CBDW)
A water mass ... See Hansen and Osterhus (2000).

Canary Basin
An ocean basin located to the west of the Canary Islands in the eastern North Atlantic Ocean. This is bound to the north by the Azores Rise and is mostly composed of the Madeira Abyssal Plain, although a smaller depression called the Seine Abyssal Plain is also found there. This has also been called the Monaco Deep. See Fairbridge (1966) and Barton et al. (1998).

Canary Current
More later.

CANIGO
A European Union research project whose goal is to understand of the marine system in the Canary-Azores-Gibraltar region of the Northeast Atlantic Ocean and its links wit the Alboran Sea. The project objectives are to obtain improved knowledge about the physical processes controlling the subtropical gyre and related mesoscale circulations through observations and modeling; to study the carbon cycle in the pelagic system and estimate the carbon flow from this system to deeper waters; to quantify the influence of coastal upwelling and Saharan dust on particle fluxes in the Canary region and its change through the last glacial and interglacial periods; and to quantify, understand and model the exchange system thorugh the Strait of Gibraltar, the processes of formation, evolution and fate of the Mediterranean outflow, and to measure the biogeochemical fluxes accompanying the water exchanges.

The program, scheduled to start in August 1996 and to last for 38 months, consists of observations with ships, moored instrumentation, drifters, and acoustic tomography. Laboratory experiments, satellite data, and numerical models will also be used. The project is coordinated by the Instituto Espanol de Oceanografia in Spain and the participants include Portgual, the UK, France, Germany, Norway, Sweden, Italy, Austria, Switzerland, Ireland and Israel. See the CANIGO Web site.

capacitance matrix method
An algorithm for imposing additional conditions on the solution of a boundary value elliptic problem at specified grid points in the interior of the computational domain. It effectively determines a modification to the right-hand side of the governing elliptic equation which will precisely satisfy the additional interior boundary conditions. Pragmatically it allows the inclusion of island and irregular coastal boundaries while retaining the use of fast and accurate elliptic solving routines at a modest additional computational expense. See Wilkin et al. (1995).

CAPE
Abbreviation for convective available potential energy.

CAPE
Acronym for Circumpolar Arctic PaleoEnvironments, an organization within IGBP-PAGES to provide the vehicle through which international and national Arctic paleo-programs can be linked. The primary emphasis of CAPE is to facilitate the scientific integration of paleoenvironmental research on terrestrial environments and adjacent margins covering the last 250,000 years of Earth history, particularly those tasks that cannot easily be achieved by individual investigators or even regionally focused research teams. See CAPE Project Members (2001).

[http://www.ngdc.noaa.gov/paleo/cape/cape.html]

Cape Basin
An ocean basin located to the west of South Africa at about 35$ ^\circ$ S in the South Atlantic Ocean. This includes the Cape Abyssal Plain which is fed by the Orange River. This has also been called the Walvis Basin. See Fairbridge (1966).

Cape Horn Current (CHC)
A current found south of approximately 42$ ^\circ$S along the coast of Chile. The west wind drift of the subtropical gyre veers south and becomes the Cape Horn Current at this latitude. The lower salinity and higher oxygen values found in the upper part of the current as it moves south indicate interaction with the estuarine circulation in the complex fjords along the coast. These properties are limited to the region next to the coast at 42$ ^\circ$S, but extend to around 100 km offshore at 51$ ^\circ$S. See Strub et al. (1998).

Cape Verde Basin
An ocean basin located at about 15$ ^\circ$ N off the west coast of Africa in the North Atlantic Ocean. It includes the Cape Verde Abyssal Plain, separated from the Madeira Abyssal Plain to the north by a belt of abyssal hills, and the Gambia Abyssal Plain. This has also been known as the North African Trough, the Chun Deep, and the Moseley Deep. See Fairbridge (1966).

Cape Verde Frontal Zone
A major discontinuity in the warm water sphere in the eastern tropical Atlantic named as such by Zenk et al. (1991). It marks the boundary between the North and South Atlantic Central Waters (NACW, SACW) that form a strong thermohaline front north of the Cape Verde Islands. See Zenk et al. (1991) and Klein and Siedler (1995).

capillary wave
A wave on a fluid interface for which the restoring force is surface tension. See Dias and Kharif (1999) and Perlin and Schultz (2000).

carbon-14 dating
A radioisotope dating method wherein a radioactive isotope of carbon, also called radiocarbon, is used to date materials containing carbon. Carbon-14 is produced in the atmosphere by a reaction between slow cosmic ray neutrons and stable nitrogen-14 and subsequently becomes incorporated into molecules of carbon dioxide by reactions with oxygen or by exchange reactions with stable carbon isotopes in molecules of carbon monoxide or carbon dioxide. These molecules are rapidly mixed through the atmosphere and hydrosphere to reach a constant level of concentration representing a steady-state equilibrium, maintained by the constant production of carbon-14 and its continuous decay to stable carbon-12.

The carbon-14 molecules enter plants tissues via photosynthesis or by absorption through roots and the concentration subsequently remains constant due to a balance between incorporation and decay. Animals feeding on such plants have a similar constant radiocarbon level. When the plants and animals die, the incorporation of carbon-14 stops while the decay into carbon-12 continues with a half-life period of 5570 years. Thus if the radiocarbon activity in a living plant or animal is known, its activity in the dead tissues of a similar plant or animal can be used to calculate the time elapsed since its death by measuring the ratio of carbon-14 to carbon-12. This is known as the carbon-14 date of the sample. See Bowen (1991) and the Radiocarbon Web site.

carbon compensation depth
The level in the ocean below which the solution rate of calcium carbonate exceeds its deposition rate. This is also called the carbonate compensation depth.

carbon cycle
Refers to the cycling of carbon in the form of carbon dioxide, carbonates, organic compounds, etc. between various reservoirs, e.g. the atmosphere, the oceans, land and marine biota and, on geological time scales, sediments and rocks. The largest natural exchange fluxes occur between the atmosphere and the terrestrial biota and between the atmosphere and the surface water of the oceans.

carbon dating
See carbon-14 dating.

carbon dioxide
This is the most important of the greenhouse gases with an atmospheric concentration of 353 ppm (in 1990), up from an estimated 260-290 in pre-industrial times (pre-1880). This gas plays a very large part in the natural carbon cycle, with the amount of carbon taken out of the atmosphere each year by plant photosynthesis being almost perfectly balanced by the amount put back into the atmosphere by the processes of animal respiration and plant decay.

The chief natural sources the burning of coal, oil and natural gas, the so-called fossil fuels, and the cutting down and burning of forests, with the latter contributing about a third as much as the former. See Revelle and Fairbridge (1957).

carbonate pump
The name given to the cycling of CaCO3 in the ocean. Plants and animals living in the euphotic zone have CaCO3 skeletons (tests) which they precipitate from dissolved calcium and carbonate ions. The CaCO3 formed this way eventually sinks and is dissolved back to calcium and carbonate ions in the deeper parts of the water column and in the sediments. The ocean circulation closes the loop by transporting the ions back to the surface waters. This pump creates a surface depletion and a deep enrichment of both DIC and alkalinity. An increase in the strength of this pump will serve to increase atmospheric CO2 since the pump variations have twice as great an effect on alkalinity as on DIC. See Najjar (1991).

Cariaco Basin
See Richards (1975).

Caribbean Current
One of two downstream branches into which the confluence of the Guiana Current and the North Equatorial Current split when encountering the Lesser Antilles. The Antilles Current flows northward along the eastward side of the Antillean Island Arc to eventually merge into the Florida Current, while the Caribbean Current flows west-northwesterly through the various passages between the Windward Islands of the Lesser Antilles.

The characteristics of the Carribean Current derived from the observed annual average density field show it to be a warm, persistent, and powerful current with a gentle increase in velocity as it flows from the Windward Islands to the Yucatan Channel. The axis of the main flow is about 20 km wide, extends from the surface to a few tens of meters below, and streams about 200-300 km off the coast of Venezuela. It then veers northwest across, over and beyond the various submarine channels of the Jamaica-Honduras Ridge and exits through the Yucatan Channel. The axis of the current has an annual average velocity of 0.50 m/s, with the spring-summer velocity (0.80 m/s) greater than that of autumn-winter (0.40 m/s). Maximum velocities greater than 2.0 m/s have been measured, and the velocities decrease with depth to speeds not greater than 0.05 m/s at 1000 m. The annual average volume transport is estimated at 30 Sv.

The trajectories of satellite-tracked drifters indicate that the trajectory of the Caribbean Current is most correctly referred to in a statistical sense, e.g. Gallegos (1996) refers to ``the loops, cusps, meanders and reversals, the presence of eddies, filaments of currents and countercurrents, and other typical motions, including turbulence, within a wide range of time and space scales.'' See Gallegos (1996).

Caribbean Sea
The largest marginal sea of the Atlantic Ocean, with a surface area of 2.52 $ \times\,{10^6}$ km$ ^2$ and a volume of 6.48 $ \times\,{10^6}$ km$ ^3$ (twice that of the Mediterranean Sea). The north and eastern boundaries are the Greater and Lesser Antilles, and the southern extent is bounded by the irregular coasts of Venezuela, Colombia and Panama. The western boundary is Central America. It is located between 8-22$ ^\circ$N latitude and 60-89$ \circ$W longitude, i.e. about 3000 km east to west and 1500 km south to north.

The average depth of the Caribbean is 4400 m, and it consists of five principal basins. They are, from east to west (with average depths):

The major sills and ridges (with maximum depths) separating the basins from each other, the Atlantic, and the Gulf of Mexico are, from east to west:

The water masses and circulation of the Caribbean have been summarized by Mooers and Maul (1998). Their summary is repeated here in slightly modified form:

The IAS [Intra-Americas Sea, i.e. the coastal, estuarine, riverine, continental shelf and deep waters of the Gulf of Mexico, Caribbean Sea, Guianas and Bahamas (including the Straits of Florida)] contains the ``roots'' of the Gulf Stream system, and its circulation is consequently dominated by throughflow, with a volume transport estimated to be about 30 Sv. The inflow is derived from the tropical and subtropical North Atlantic Ocean. For example, the Guyana Current is a major source of inflow from the tropical Atlantic Ocean. The majority of the inflow enters the Caribbean Sea through several passages, of variable sill depth, between the Antilles Islands and, to a lesser estent, the Windward Passage. The remainder bypasses the Caribbean Sea via the Antilles Current, some of which flows through the Bahamas Islands and enters the Straits of Florida.

Associated with the throughflow regime is the thermohaline-driven lower branch of the meridional overturning circulation known as the Deep Western Boundary Current (DWBC), which flows equatorward at a depth of about 3 km along the periphery of the IAS continental slope. This intense, deep flow is part of the Global Conveyer Belt in the Atlantic and has a volume transport of about 15 Sv. Although little DWBC water spills directly into the IAS through the major deep passages, it mixed with the ambient middepth Atlantic waters to form the remarkably uniform bottom water in the Caribbean Sea Basin. Dynamically, the role of the DWBC on IAS circulation is essentially unknown.

Surface waters of the tropical Atlantic Ocean (T $ \approx$ 28$ ^\circ$C, S $ \approx$ 36 ppt) flow into the IAS through the Antilles Passages, and except for extreme winters, flow out the Straits of Florida with almost the same general T-S properties. Below the surface, at typically 200 m, the subtropical underwater (SUW) dominates the shape of the T-S curve (T $ \approx$ 22$ ^\circ$C, S $ \approx$ 36.7 ppt) in the main flows of the Gulf Stream system. Outside the current, the salinity is typically reduced to S $ \approx$ 36.2 ppt, due to mixing with the ambient waters, usually of riverine origin but also due to excess of precipitation (P) over evaporation (E), particularly in the northern Gulf of Mexico. SUW is formed in the central tropical Atlantic where E $ >$ P and sinks along an isopycnal surface before and during IAS passage.

The next 500 m or so of the water column is dominated by Western North Atlantic Central Water (WNACW) with a typical temperature range of 20$ ^\circ$C $ >$ T $ >$ 8$ ^\circ$C and salinity range of 36.3 $ >$ S $ >$ 35.2 ppt. At about 700 m, the characteristic salinity minimum of Antarctic Intermediate Water (AAIW) near S $ \approx$ 34.8 ppt and T $ \approx$ 7$ ^\circ$C can be traced from the northern Straits of Florida through the IAS, including the western Gulf of Mexico (where SUW is only found in Loop Current anticyclonic edies), through the Caribbean Sea and eventually of course to its (E $ <$ P) source off Antarctica. Finally, in the deepest waters, $ >$1000 m or so, the mid-depth waters of the Atlantic (slightly increased salinity) are generally recognized. The deep waters of the IAS are remarkably uniform (T $ \approx$ 4$ ^\circ$C, S $ \approx$ 35 ppt) and created by overflows of the sills in the deeper passages (especially the Anegada and Windward Passages).

The surface flow through the island passages organizes into the Caribbean Current that flows westward off the northern coast of South America and then northward along the eastern coast of Central America. Subsequently, it becomes known as the Yucatan Current as it flows through the Yucatan Channel and then becomes known as the Loop Current as it penetrates northward into the eastern Gulf of Mexico. It then turns anticyclonically southward to exit to the east through the Straits of Florida, where it is known as the Florida Current and its volume transport is about 30 Sv. The persistent cyclonic Panama-Colombian Gyre (PCG), located in the southwestern Caribbean Sea, where it interacts with the plume of the Magdelena River, is the other major component of the surface general circulation.

The flow through the Antillean Passages is spatially complex (i.e. undercurrents and countercurrents; bottom trapping) and temporally variable on time scales of months and years wit no clear annual cycle.

The deep circulation is largely unexplored but there are dynamical reasons to anticipate a mean cyclonic flow along bottom topography in both the Caribbean Sea and the Gulf of Mexico. ... The Caribbean Sea is composed of several basins that divide the deep circulation. Geochemical data provide some estimates of deep-water age and residence times, but the physical processes involved (i.e. flow over the deep sills of the island passages) are onlly now being investigated theoretically and observationally.

The macroscale, seasonal wind forcing (which is regional as well as remote, i.e. from the North Atlantic, in nature) modulates the general circulation of the open basins by approximately 10% and may lead to flow reversals over shelves. For example, the summertime intensification of the trade winds leads to ecologically significant coastal upwelling and westward shelf flows along the northern coasts of South America, the Yucatan Peninsula and Cuba.
See Wust (1964), Gordon (1967), Kinder et al. (1985), Gallegos (1996) and Mooers and Maul (1998).

Caribbean Surface Water (CSW)
See Corredor and Morell (1999).

[http://cima.uprm.edu/cats/cats.htm]
[http://cima.uprm.edu/~morelock/mor2.htm]

Carpenter, William (1813-1885)
See Peterson et al. (1996), p. 93.

Carruthers residual current meter
A current meter designed to measure and record the residual current over a longer period of time. In a manner similar to that of the Ekman current meter, a device drops small metal balls into a compass box after a certain number of turns of the propeller. The average velocity and direction are obtained by counting, after an extended period of time, the number and distribution of balls dropped (of over 22,000 available) into the slots of the compass box. See Sverdrup et al. (1942).

CARUSO
Acronym for CARbon dioxide Uptake by the Southern Ocean, an experiment undertaken from January 1988 to December 2000 to test the hypothesis that ``the carbon dioxide uptake by the Southern Ocean is being dominated by synergistics of light and iron regulating the photosynthetic carbon dioxide fixation of large diatoms and carbon export into deeper Antarctic waters.'' The specific objectives of the program were:

[http://kellia.nioz.nl/projects/caruso/]

Caspian Sea
See Zenkevich (1957) and Zenkevitch (1963).

Catalan Sea
See Balearic Sea.

CATCH
Acronym for the Couplage avec l'ATmosphère en Conditions Hivernales experiment, which took place in the North Sea in January and February 1997. See Eymard (1999).

CATO Expedition
See Scripps Institution of Oceanography (1979a).

CCD
Abbreviation for Calcite Compensation Depth, defined as the depth at which the CaCO3 content of sediments reaches 20%.

CDW
Abbreviation for Circumpolar Deep Water.

CEAREX
Acronym for Coordinated Eastern Arctic Experiment, a multi-national and multi-platform field program carried out in the Greenland and Norwegian Seas (north to Svalbard) from Sept. 1988 through May 1989. It was a collaboration between Canada, Denmark, France, Norway and the United States and consisted of four phases: the Polarbjorn Drift Phase, the Whaler's Bay/SIZEX Phase, the Oceanography Camp Phase, and the Acoustic Camp Phase. See Pritchard and et al. (1990).

[http://nsidc.org/NSIDC/CATALOG/ENTRIES/nsi-0020.html]

Celebes Sea
Alternate name for the Sulawesi Sea.

Celtic Sea
A shallow embayment of the eastern North Atlantic bounded by Southern Ireland, southwest Wales, Cornwall and Brittany. It is usually separated from the Irish Sea by a line drawn from Ramsey Island to Carnsore Point and from the English Channel by a line drawn from Ushant to Lands End. The seaward limit is usually set at the slope break at about 165-185 m. See Cooper (1967), Fairbridge (1966), Pingree (1980) and Simpson (1998).

Celtic Seas
A term used for the European shelf seas to the west and south of the British Isles. These include the Hebrides and Malin shelves west of Scotland, the Irish Shelf, the English Channel, the Celtic Sea and the Irish Sea. See Simpson (1998).

Cenderawasih Bay
A bay on the northern coast of Irian Jaya centered at approximately 135$ ^\circ$ E and 2.5 deg. S at the southwestern edge of the Pacific Ocean. It connects with the Pacific via the Woinui and Yapen Straits and is bordered immediately to the north by the New Guinea Trench.

belcentersofaction

centers of action
Large semipermanent belts of high or low sea level pressure distributed around the Earth that largely control the general circulation of the atmosphere and the concomitant long-term weather patterns. The term was originally used by Teisserenc de Bort in 1881 to describe maxima and minima of pressure on daily charts, but has evolved to have the more global meaning. These centers include the Icelandic Low, the Aleutian Low, the Pacific High, the Azores High, the Siberian High, and the Asiatic Low. See Herman and Goldberg (1985).

Central South Equatorial Current
One of three distinct branches into which the South Equatorial Current splits in the western South Atlantic. See Stramma (1991).

Central Water
In physical oceanography, a term used to identify thermocline water masses in all three oceans. The water arrives at the thermocline via a process known as subduction. Central Water is characterized by T-S relationships that span a large range that is nonetheless well-defined by the method of formation. The term was originally introduced to differentiate between thermocline water of the central north Atlantic Ocean (now known as NACW) and water from the shelf area to west, but now has the abovementioned broader meaning. See Tomczak and Godfrey (1994).

CEPEX
Acronym for Central Equatorial Pacific Experiment, conducted in March and April 1993 with the goal of establishing the respective roles of cirrus radiative effects and surface evaporation in limiting maximum surface temperatures in the equatorial Pacific. It examined the validity of a hypothesized thermostat effect which may limit greenhouse warming. Deep intensive convection is observed to occur when tropical SSTs exceed about 27$ ^\circ$ C. This produces cirrus (ice particle clouds) anvils that spread out over millions of square kilometers. It is hypothesized that while these clouds trap outgoing infrared radiation, they also reduce incoming solar radiation, the net effect being to stabilize SSTs, thereby acting in effect as a thermostat.

CEPEX employed surface, airborne, and space-borne platforms to measure radiation fluxes, cirrus radiative and microphysical properties, vertical water vapor distribution, evaporation from the sea surface, and precipitation. The specific objectives were:

See Ramanathan et al. (1995).

[http://www-c4.ucsd.edu/~cids/cepex/]
[http://www.joss.ucar.edu/cgi-bin/codiac/projs?CEPEX]

CEPTE
Acronym for Central Equatorial Pacific Tomography Experiment, a long-term, 1000 km scale tomography experiment taking place from Dec. 1998 to Dec. 2000. The purpose is to measure the shallow overturning of a meridional circulation cell, i.e. a subtropical circulation cell (STC) that has been hypothesized as one mechanism by which El Nino/La Nina events in the tropics are connected to the subtropical ocean. CEPTE involved five JAMSTEC tomography moorings deployed in an array about 1000 km across just north of the equator at about 180$ ^\circ$W.

Ceram Sea
See Seram Sea.

CESNA
Acronym for the Climate Expert System for the North Atlantic, part of a project to develop a practical system that can manipulate qualitative information in a way that facilitates insights into observed and anticipated climate changes. At present CESNA can be used to estimate changes in mean winter and annual climatic characteristics with a one year lead time in the region that includes eastern North America, the North Atlantic, the adjacent Arctic seas and much of Europe. See the CESNA Web site.

CFC
See chlorofluorocarbon.

CFL
Abbreviation for Courant, Friedrichs, and Levy, the discoverers of a time step limitation for numerical simulations of partial differential equations.

Chain Fracture Zone
One of the pathways (along with the Romanche Fracture Zone) for AABW and lower NADW from the western to the eastern trough of the equatorial Atlantic Ocean across the Mid-Atlantic Ridge. To the west of the CFZ sill, the AABW and NADW cores are separated by a deep thermocline marking the vertical transition between them. This thermocline erodes eastward and vanishes in the eastern basin. See Mercier and Morin (1997) and Messias et al. (1999).

Challenger Expedition (1872-1876)
A three and a half year voyage starting in 1872 that laid the scientific foundation for every major branch of oceanography. The ship, captained by George S. Nares and later Frank T. Thomson, took over 350 stations in all the oceans except the Arctic and logged 68,890 nautical miles. Perhaps the only ultimately unsatisfying aspect of the expedition was that the ship, a spar-decked vessel with auxiliary steam power, was slow and clumsy and had the habit of rolling about 50$ ^\circ$ to either side. The expedition was led by Sir Wyville Thompson, with his chief assistant John Murray and the expedition's chemist J. Y. Buchanan also playing major roles.

The observations and records obtained aboard the Challenger furnished data for charting the main bathymetric contours of the ocean basins, established the cold and relatively constant nature of temperatures at great depths, located the exact position of many islands and sea mounts, established that there was no zone in the sea in which life did not exist, and enabled the construction of accurate charts of the principle surface (and some subsurface) currents in the world ocean. The deep sea data were obtained with trawls lowered on hemp ropes. The ship dragged for samples in water as deep as 4,475 fathoms and trailed as much as eight miles of line in trawls that took 12 or 14 hours to complete.

The foundations of marine geology were laid by Murray with his study of the deep-sea sediments obtained in the trawls. The sediments discovered were newly classified as globigerina, radiolarian or diatom oozes or red clay, and their spatial distribution was mapped. The plankton nets, simple bags of muslin or silk attached to iron rings one foot in diameter captured many new planktonic forms, permanently changing that branch of marine biology. Many new and different forms of life were dredged from great depths, permanently dispelling the notion that these depths were lifeless and founding deep-sea biology. The expedition's chemist Buchanan took seventy-seven water samples throughout the oceans, deriving data from these that formed the foundation of chemical oceanography. He also dispelled the myth of Bathybius.

The scientific results of the expedition were published in fifty large volumes over fifteen years, edited first under the direction of Thompson and, after his death, by Murray. The best artists in England were hired to create the illustrations. The funding for this publishing endeavor was not included as part of the budget of the expedition and it was a constant struggle for Thompson and Murray to obtain financial resources to complete the endeavor, so it might also be said that the foundations for the difficulty of obtaining funds for oceanographic research were also laid by this expedition.

The Challenger Expedition probably contributed more to the science of oceanography than any single expedition before or after. It marked the beginning of oceanography as a disciplined science, with the scientists establishing a pattern of scrupulously precise observations and efficiency. While the quality of ships and of sampling and measuring devices have greatly improved since 1872, it is doubtful that the standards set by the Challenger Expedition will ever be exceeded. It was truly a landmark in oceanography. See Thomson and Murray (1884-1895).

Challenger Report
A fifty volume set of reports on the results of the Challenger Expedition. The six main sections of the report were narrative, physics and chemistry, deep-sea deposits, botany, zoology and a summary. A more detailed breakdown is:

I. Narrative. Three bound volumes.
II. Physics and Chemistry. Two bound volumes.
III. Deep-Sea Deposits. One bound volume. (583 pp.) IV. Botany. Two bound volumes. V. Zoology. Forty bound volumes.
VI. Summary. Two bound volumes.

CHAMP
Acronym for the Coral Health And Monitoring Program, a NOAA project to provide services to help improve and sustain coral reef health throughout the world. The goals include establishing an international network of coral reef researchers to share information about and monitor coral health, providing near real-time data products derived from satellite images and monitoring stations at coral reef areas, providing a data repository for historical data, and adding to the general fund of coral reef knowledge. See the CHAMP Web site.

chaos
That which we should be mindful of.

Jule Charney (1917-1981)
A dominant figure in atmospheric science and geophysical fluid dynamics in general in the three decades following WWII.

[http://www.nap.edu/readingroom/books/biomems/jcharney.html]

chemical oceanography
The most thorough and complete series of reviews on the topic can be found in the Chemical Oceanography series. The chapters to date are:
  1. Ocean and estuarine mixing processes - K. F. Bowden
  2. Sea water as an electrolyte solution - M. Whitfield
  3. Chemical speciation - W. Stumm and P. A. Brauner
  4. Adsorption in the marine environment - G. A. Parks
  5. Sedimentary cycling and the evolution of sea water - F. T. Mackenzie
  6. Salinity and the major elements of sea water - T. R. S. Wilson
  7. Minor elements in sea water - P. G. Brewer
  8. Dissolves gases other than CO$ _2$ - D. R. Kester
  9. The dissolved gases-carbon dioxide - G. Skirrow
  10. Chemistry of the sea surface microlayer - P. S. Liss
  11. The micronutrient elements - C. P. Spencer
  12. Biological and chemical aspects of dissolved organic material in sea water - P. J. Le B. Williams
  13. Particulate organic carbon in the sea - T. R. Parsons
  14. Primary productivity - G. E. Fogg
  15. The hydrochemistry of landlocked basins and fjords - K. Grasshof
  16. Reducing environments - W. G. Deuser
  17. Marine pollution - E. D. Goldberg
  18. Radioactive nuclides in the marine environment - J. D. Burton
  19. Analytical chemistry of sea water - J. P. Riley et al.
  20. The electroanalytical chemistry of sea water - M. Whitfield
  21. Extraction of economic inorganic materials from the sea - W. F. McIlhenny
  22. Seaweed in industry - E. Booth
  23. Marine drugs: chemical and pharmacological aspects - H. W. Youngken, Jr. and Y. Shimizu
  24. Oceanic sediments and sedimentary processes - T. A. Davies and D. S. Gorsline
  25. Weathering of the Earth's crust - G. D. Nicholls
  26. Lithogenous material in marine sediments - H. L. Windom
  27. Hydrogenous material in marine sediments: excluding manganese nodules - H. Elderfield
  28. Manganese nodules and other ferro-manganese oxide deposits - D. S. Cronan
  29. Biogenous deep sea sediments: production, presentation and interpretation - W. H. Berger
  30. Chemical diagenesis in sediments - N. B. Price
  31. Factors controlling the distribution and early diagnosis of organic matter in marine sediments - E. T. Degens and K. Mopper
  32. Interstitial waters of marine sediments - F. T. Manheim
  33. The mineralogy and geochemistry of near-shore sediments - S. E. Calvert
  34. The geochemistry of deep-sea sediments - R. Chester and S. R. Aston
  35. Sea-floor spreading and the evolution of the ocean basins - E. J. W. Jones
  36. Sea-floor sampling techniques - T. C. Moore, Jr. and G. R. Heath
  37. Suspended matter in sea-water - W. M. Sackett
  38. Aerosols chemistry of the marine atmosphere - W. M. Berg Jr. and J. W. Winchester
  39. The organic chemistry of marine sediments - B. R. Simoneit
  40. Determination of marine chronologies using natural radionuclides - K. K. Turekian and J. K. Cochran
  41. Estuarine chemistry - S. R. Aston
  42. Coastal lagoons - L. D. Mee
  43. Influence of pressure on chemical processes in the sea - F. J. Millero
  44. The Geochemical Ocean Sections Study-GEOSECS - J. A. Campbell
  45. Trace elements in sea-water - K. W. Bruland
  46. The chemistry of interstitial waters of deep sea sediments: interpretation of deep sea drilling data - J. M. Gieskes
  47. Hydrothermal fluxes in the ocean - G. Thompson
  48. Natural water photochemistry - O. C. Zafiriou
  49. Organic matter in sea-water: biogeochemical processes - C. Lee and S. G. Wakeham
  50. Marine pollution - M. R. Preston
  51. Electroanalytical chemistry of sea water - C. M. G. Van Den Berg
Compare to biological, geological and physical oceanography. See Holland (1978).

chemical tracers
See England and Maier-Reimer (2001).

Chile Current
Another name used for the Peru Current.

Chile-Peru Current
Another name used for the Peru Current.

China Coastal Current
A southward flowing current along the Chinese coast in the Yellow Sea. This current brings low salinity water from the northern parts of the Yellow Sea, particularly the Bohai Gulf, to the south and on into the East China Sea where part of it continues along the coast and another part joins and turns eastward with the northward flowing Taiwan Current.

chlorine titration
The method developed by Knudsen and others in 1902 to determine the chlorinity and therefore salinity of a sea water sample. See Dietrich (1963).

chlorinity
A concept originally defined (circa 1900) to circumvent the difficulties inherent in attempting to directly measure the salinity of sea water. It was determined by volumetric titration using silver nitrate and originally defined as ``the weight in grams (in vacuo) of the chlorides contained in one gram of seawater (likewise measured in vacuo) when all the bromides and iodides have been replaced by chlorides.'' This was defined in terms of the atomic weights known in 1902 and as such was dependent on any changes in their determinations. The weights did change so the definition was kept in terms of the 1902 atomic weights until a new definition was determined in 1937. The new definition of chlorinity as ``the mass of silver required to precipitate completely the halogens in 0.3285234 kg of sample seawater'' was free of this limitation.

The chlorinity was later defined in terms of electrical conductivity when it was determined that density may be predicted from conductivity measurements with nearly an order of magnitude better precision than from a chlorinity titration. This change was also predicated on the development of precise and reliable electronic instruments in the 1950s to perform the measurements. This led to the present method of calculating the chlorinity (and thence salinity) by experimental determination of a relationship between chlorinity and the conductivity ratio of a sample at atmospheric pressure and 15$ ^\circ$ C to that of a standard seawater. See Lewis (1980) and Lewis and Perkin (1978).

chlorofluorocarbon (CFC)
Any of a group of exceptionally stable compounds containing carbon, fluorine, and chlorine, which have been used especially as refrigerants and aerosol propellants. CFCs are climatically significant for their ability to break down ozone molecules in the atmosphere. There are several kinds of CFCs, the most common being CFC-11, CFC-12, CFC-113, CFC-114 and CFC-115, having ODPs of, respectively, 1, 1, 0.8, 1 and 0.6. They are also significant as a greenhouse gas since, molecule for molecule, they are 10,000 times more efficient in trapping heat in the atmosphere than carbon dioxide. The GWPs of CFC-11 and CFC-12 are, respectively, 5000 and 8500.

chlorosity
The number of grams of chloride and chloride equivalent to the bromide in one liter of sea water at 20$ ^\circ$ C. See Riley and Chester (1971).

Chukchi Sea
One of the seas found on the Siberian shelf in the Arctic Mediterranean Sea. It is located to the east of the East Siberian Sea, to the north of the Bering Strait, and adjoins the Arctic Ocean proper to the north. This has also been called the Chukotsk Sea. See Zenkevitch (1963), Weingartner et al. (1998) and Münchow et al. (1999).

Chukotsk Sea
See Chukchi Sea.

CICAR
Acronym for Cooperative Investigation of the Caribbean and Adjacent Regions, an IOC Coordination Group.

CINCS
A project to study pelagic-benthic coupling in the oligotrophic Cretan Sea. The primary aim of the study was to study biogeochemical exchanges between the Cretan continental shelf and the adjacent open marine ecosystem of the oligotrophic Cretan Sea.

[http://www.ncmr.ariadne-t.gr/frame/CINCS.html]
[http://bali.cetiis.fr/mtp/MTP1/Projets/cincs.html]

circalittoral zone
This has also been called the outer sublittoral zone.

circle of mean temperature
A concept advanced by Sir James Clark Ross in 1847 in which he posited that there is a latitude circle where the mean temperature of the sea is constant through its entire depth. North of this line, located at 56$ ^\circ$ S and having a temperature of 39.5$ ^\circ$ F, the sun warms the sea to temperatures above this mean temperature such that at 45$ ^\circ$ S the mean temperature line has descended to 600 fathoms. The limit of the sun's influence was ascertained to be 1200 fathoms, at which latitude the surface temperature was 78$ \circ$ F. Similarly, the mean temperature line descends to the south of the circle where it exists at a depth of 750 fathoms at 70$ ^\circ$ S, above which the temperature decreases to a surface minimum of 30$ ^\circ$ F. The latitude of the circle corresponds closely to the mean position of what is now known as the Antarctic Convergence, thus leading to Ross identifying an important oceanic feature for the wrong reasons. The figure of 39.5$ ^\circ$ F was used because Ross, throughout his 3 year voyage, consistently measured temperatures at depths as great as 1200 fathoms but never record a temperature lower than 39.5$ ^\circ$ F due to pressure distortion effects on his thermometers. See Deacon (1971).

Circumpolar Deep Water (CDW)
The most extensive water mass found in the ACC, CDW is usually further split into Upper Circumpolar Deep Water (UCDW) and Lower Circumpolar Deep Water (LCDW). UCDW is characterized by an oxygen minimum and nutrient maxima (with sources in the Indian and Pacific Oceans) as well as by a relative minimum in temperature south of the Subantarctic Front (SAF) induced by the overlying Antarctic Intermediate Water (AAIW) and Winter Water. LCDW is characterized by a salinity maximum and nutrient minima derived from North Atlantic Deep Water (NADW).

The source region of the split (and LCDW) is in the southwest Atlantic where relatively warm, salty, oxygen rich and nutrient poor NADW meets the ACC just below the oxygen minimum therein, thus splitting the CDW into two parts. The upper branch of this split retains the oxygen minimum layer present before the split, with the lower branch also showing an oxygen minimum induced by high oxygen concentrations in both the overlying NADW and the underlying Antarctic Bottom Water. The latter minimum has been eroded via mixing by the time the LCDW reaches the Greenwich Meridian, to be replaced by a general increase in oxygen from the UCDW minimum to the bottom.

The oxygen minimum of the UCDW lies slightly below the phosphate and nitrate maxima. At the Drake Passage the concentrations in this minimum increase from 3.7 mL/L in the Subantarctic Zone (SAZ) to 4.1 mL/L in the Antarctic Zone (AZ). The NADW influx to the east of this reverses this trend such that concentrations decrease to the south at the Greenwich Meridian, e.g. from 4.2 mL/L near the SAF to less than 4.1 mL/L near the PF. The mean concentrations of the nutrient maxima at the Drake Passage or 2.42 $ \mu$mol/L for phosphate and 35.4 $ \mu$mol/L for nitrate. The phosphate maximum is eroded by NADW north of the PF such that it is reduced to 2.36 $ \mu$mol/L at the Greenwich Meridian, although it is unchanged south of the PF. The nitrate concentration erodes slightly to 34.8 $ \mu$mol/L north of the SAF at the Greenwich Meridian, while it increases to as high as 36.8 $ \mu$mol/L near the PF.

The mean salinity at the LCDW salinity maximum at Drake Passage is 34.729, the lowest in the Southern Ocean since there it is most remote from the NADW source of the maximum. The phosphate minima concentration at Drake passage is about 2.25 $ \mu$mol/L while the nitrate minima is 32.5 $ \mu$mol/L. That are reduced to, respectively, 1.98 $ \mu$mol/L and 29.9 $ \mu$mol/L, north of the PF at the Greenwich Meridian, with the concentrations reduced even south of the PF, although to a lesser degree.

The paths of LCDW in the Atlantic are summarized by Onken (1995):

In the Atlantic, LCDW is found in all basins. From the Argentine Basin it flows north and invades the Brazil Basin via the Vema and Hunter Channels and the Lower Santos Plateau. At the northern end of the Brazil Basin, the flow splits into an eastward branch through the Romanche Fracture Zone and a northwestward one, which spills over the broad equatorial sill into the Guiana Basin and finally into the North American Basin, where it can be identified up to 40$ ^\circ$N. The eastern North Atlantic, that is, the Cape Verde, Canary and Iberian Basins, are supplied via the Vema Fracture Zone at $ \approx$11$ ^\circ$N. Here LCDW influence has been traced northward up to $ \sim$32$ ^\circ$N. The Sierra Leone and Angola Basins get their LCDW contribution through the Romanche Fracture Zone from the Brazil Basin; however, the abyss of the southwesternmost corner of Angola Basin is also partly influenced by LCDW, which originates from the Cape-Agulhas Basin and spills over deep sills in the Walvis Ridge named the Walvis Passage.
See Reid et al. (1977), Whitworth and Jr. (1987) and Onken (1995).

CIRFZ
The Circulation in the Romanche Fracture Zone experiment took place in November-December 1994. It was a cooperative effort between American and French scientists aboard the N/O Le Noroit to study the movement of Antarctic Bottom Water (AABW) through the Romanche Fracture Zone. During the 20 day experiment 55 HRP profiles and more than 30 CTD stations were completed, with most of the work concentrated in and around the Zone. Twelve more HRP dives comprising two equatorial sections were made after the work in the Zone to examine the structure of the deep equatorial jets. It was found that very strong eastward velocities in the deepest part of the Zone were responsible for high levels of turbulent mixing of the AABW. See Polzin et al. (1996) and Montgomery (1996).

C-LAB
Acronym for Communication-Linked Automatic Buoy, a moored oceanographical and meteorological buoy system operating in Prince William Sound, Alaska since late 1991. This started out as part of the CFOS project but became part of the SEA project in 1994. The buoy is moored to the southeast of Naked Island, Alaska in water 190 m deep. It is usually deployed in late February or early March and recovered in late November. C-LAB consists of a suite of meteorological instruments to measure wind speed and direction, air temperature, and barometric pressure. Water temperature measurements are made at 11 different depths, and there is a fluorometer at 10 m depth to measure the fluorescence of microscopic phytoplankton. Data are collected 12-18 times per day via the ARGOS system. See the C-LAB Web site.

clapotis
More later.

Clausius-Clapeyron equation
An equation expressing rate of change of the saturation vapor pressure with temperature. It is given by

$\displaystyle { {d{e_w}} \over {dT} }\,=\, { {L_v} \over {T({v_v}\,-\,{v_w})} }$

where $ e_w$ is the saturation vapor pressure, $ T$ the temperature, $ L_v$ the latent heat of vaporization, $ v_v$ the specific volume of the vapor phase, and $ v_w$ the specific volume of the water phase. This is given approximately by

$\displaystyle {L_v}(T)\,\simeq\,2.5008\times{10^{-6}}\,-\, 2.3\times{{10}^3}\,t\,\,J\,{\text{kg}^{-1}}$

where $ t$ is the temperature in degrees Celsius.

CLIMAP
Acronym for Climate: Long-Range Investigation Mapping and Prediction, a project started in 1971 by a consortium of scientists from many institutions to study the history of global climate over the past million years, particularly the elements of that history recorded in deep-sea sediments. One goal of CLIMAP, the Last Glacial Maximum Project, was to reconstruct the boundary conditions for the climate 18,000 years ago to serve as boundary conditions for atmospheric GCM simulations. See Project (1976) and Project (1981).

climate
Traditionally defined in terms of the mean atmospheric conditions at the earth's surface. Peixoto and Oort (1992) offer the more technical and broader "set of averaged quantities completed with higher moment statistics (such as variances, covariances, correlations, etc.) that characterize the structure and behavior of the atmosphere, hydrosphere, and cryosphere over a period of time." Any definition as least implicitly involves some sort of averaging procedure to distinguish the climate from that more instantaneous quantity we call the weather.

climate drift
The divergence of a coupled atmosphere-ocean numerical model simulation from an initial or observed state due to imbalances between the components. See also systematic errors and flux correction. The origin of this drift is the mismatch between the externally-prescribed air-sea surface fluxes used to drive each model during the spin-up phase and the surface fluxes computed by the coupled model once the ocean and atmosphere components are joined. Sources for this difficulty involve shortcomings in the simulation of extensive layers of marine stratocumulus clouds in tropical and sub-tropical regions, errors in surface fluxes, insufficient model resolution, spin up and initialization difficulties, sea ice representation problems, and the treatment of the vertical penetration of heat into the ocean. This has also been called solution drift. See Sausen et al. (1988), Manabe and Stouffer (1988), and Meehl (1992).

climate forcing agents
Any of several factors which can change the balance between the energy (in the form of solar radiation) absorbed by the Earth and that emitted by it in the form of long-wave infrared radiation, i.e. the radiative forcing of climate. Examples include changes in the amount or seasonal distribution of solar radiation that reaches the Earth due to Milankovitch forcing, changes in the albedo due to desertification, deforestation, or changes in ice area, and the absorption of solar radiation by aerosols in the atmosphere.

Clyde Sea
See Simpson and Rippeth (1993).

CME
Abbreviation for Community Modeling Effort, a WOCE component to design and execute a series of baseline calculations of the wind- and thermohaline-driven, large-scale ocean circulation, to make comparisons of these simulations with observations, and to evaluate the performance of the models and identify needed improvements. See the CME Web site.

CMICE
See Current Meter Intercomparison Experiment.

CMIP
Abbreviation for Coupled Model Intercomparison Project, an analog of AMIP for global coupled ocean-atmosphere general circulation models. It began in 1995 under the auspices of CLIVAR and is supported (as is AMIP) by PCMDI. The purpose of CMIP is to examine climate variability and predictability as simulated by the models, and to compare the model output with observations where available. See the CMIP Web site.

CMO
Abbreviation for Coastal Mixing and Optics program, a project to study the mixing of ocean water on the continental shelf, and the effect of the mixing on the transmission of light through the water.

[http://wavelet.apl.washington.edu/CMO/]
[http://www.whoi.edu/science/AOPE/cofdl/cmo/]

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