Cn-Cz

 

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.

 

CNES

Abbreviation for Centre National d'Etudes Spatiales (France).

 

CNRS

Abbreviation for Centre National de la Recherche Scientifique (France).

 

COADS

Acronym for Comprehensive Ocean Air Data Set, a CGCP program to update and enhance the most extensive and widely used set of surface marine data available for the global ocean over the past 150 years. See the COADS Web site.

 

COARDS

Acronym for Cooperative Ocean-Atmosphere Research Data Service, a NOAA branch whose purpose is to provide high quality, well documented gridded datasets and software that can analyze and visualize these data for the purpose of examining climate change. See the COARDS Web site.

 

COARE

Acronym for Coupled Ocean-Atmosphere Response Experiment, a TOGA experiment. Additional information can be found at the TOGA COARE Web site.

 

coarse particle mode

One of three categories used to summarize the distribution of atmospheric aerosols in terms of production mechanism and particle size, the others being the nucleation and accumulation modes. The coarse particle mode is greater than 1 m in diameter and its production mechanism is by mechanical processes. See Jaenicke (1993b).

 

coastal trapped wave

To be completed.

 

CODATA

Acronym for Committee on Data for Science and Technology, an ICSU committee. See the CODATA Web site.

 

COHMAP

The Cooperative Holocene Mapping Project (COHMAP) was an initiative to assemble a global array of well-dated paleoclimate data and use a GCM to identify and evaluate causes and mechanisms of climate change over the last 18,000 years. See Project (1988).

 

COLA

Acronym for the Center for Ocean-Land-Atmosphere Studies, located at the Institute of Global Environment and Society at Calverton, Maryland. See the COLA Web site.

 

cold start problem

In climate modeling, this is a problem that results from beginning a model simulation at a point in time when the climate response to natural and anthropogenic forcing that happened before the start of the simulation is already in progress. An example would be specifying 1950 initial conditions for a simulation of the effects of anthropogenic CO2 increases when the CO2 increases although the CO2 increases started in the latter half of the 19th century. This results in a simulation that is missing at least 50 years of the time evolution of the modeled system's response to increasing atmospheric CO2, which can be vital to the prediction of future states of a system with components that change on time scales greater than 50 years, e.g. the ocean.

 

collection of cloud water

In cloud microphysics, the rate at which the precipitation content increases as a result of the large falling drops intercepting and collecting small cloud droplets lying in their paths. See Houze (1993).

 

community

An aggregation of species that live together at some locality that relate to each other ecologically, i.e. a local set of functionally interdependent species. Contrast with assemblage.

 

collision broadening

See pressure broadening.

 

complex demodulation

In statistics, this is a procedure used when a time series contains significant energy in specific frequency bands. See Bloomfield (1976).

 

Comprehensive Ocean Air Data Set

This is an extensive data set that was created by combining, editing and summarizing global in situ marine data from many sources. It covers the period 1854-1992. It is a cooperative project among ERL, NOAA, the NCDC, CIRES and NCAR. Extensive hypertext documentation is available. There is also a further processed version of this data set called UWM/COADS. See Woodruff et al. (1987).

 

computational grid

A mapping of discrete points onto a continuum (e.g. the ocean, the atmosphere, etc.) to comprise a grid-like structure. This is done to enable a numerical solution of the equations governing the specific continuum in cases where analytical solutions are impossible or infeasible due to irregular boundary conditions, nonlinearities in the governing equations, or some combination thereof. A discretized version of the equations is solved at each point in the grid, and the collection of these solutions is combined (usually graphically) to recover a continuum-like solution. It is hoped that this solution well approximates the hypothesized correct solution.

 

computational mode

An artifact of numerical solution procedures that use a centered scheme for temporal advancement, i.e. one that requires information at three time levels. Starting such a scheme requires two independent initial conditions, one specified and the other calculated from this using a temporal scheme requiring only two time levels. This results in a solution that is actually the sum of two solutions, one related to the actual physics of the problem and the other purely an artifact of the numerical procedure. The numerical solution usually alternates at each time step, resembling a sawtooth wave over time, and can be damped by averaging the solution over two consecutive time steps at suitably chosen intervals. See Kowalik and Murty (1993).

 

concentration basin

See mediterranean sea.

 

concurrent range biozone

In biostratigraphy, a type of biozone in which the co-occurrence of overlapping taxa is used for definition. See Briggs and Crowther (1990), pp. 466-467.

 

conditional instability

See conditionally unstable.

 

conditional instability of the second kind

The process, abbreviated CISK, where low-level convergence in a wind field produces convection and cumulus formation. This releases latent heat which enhances the convergence and increases convection. This is a positive feedback loop that may lead to the formation of a large-scale disturbance such as a hurricane.

 

conditionallyunstable

An atmospheric condition where the temperature lapse rate lies between the dry and saturated adiabatic lapse rates. That is, the environment is statically stable with respect to dry air but unstable with respect to saturated air. This region is usually located between the lower level of free convection (LFC) and the upper limit of convection (LOC).

 

conformal projection

A map projection that preserves the angles between intersecting curves and is characterized by metric coefficients independent of direction at a point, although they may vary from point to point. Examples include the polar stereographic and Mercator projections.

 

conglomerate

In geology, a coarse-grained rock with rounded particles of broken-down rock (clasts) greater than 2 mm in size.

 

Coniacian

The third of six ages in the Late Cretaceous epoch, lasting from 88.5 to 87.5 Ma. It is preceded by the Turonian age and followed by the Santonian age.

 

conjunction

In tidal mechanics, that instant when the Earth-centered longitudes of the Moon and Sun are identical, i.e. they are co-linear on the same side of the Earth. This is also the time of the new moon and of one of two monthly spring tides. See also opposition.

 

consecutive range biozone

In biostatigraphy, a type of biozone where one (or more) of the zone fossils ranges through an interval unaccompanied by taxa that overlap with it at other levels. See Briggs and Crowther (1990), pp. 466-467.

 

conservation laws

More later.

 

consistency

In numerical modeling, a numerical computational scheme is said to be consistent if the discrete algebraic equations created by the process of discretization recover or reduce to the original continuum differential equations as the spacing in the computational grid is shrunk to zero. The scheme is said to be unconditionally consistent if the above is true no matter how (i.e. in what order, etc.) the grid is shrunk. Thus consistency deals with relations between equations in their continuum versus discrete forms, as opposed to convergence.

 

consumer

In marine ecology, a heterotrophic organism that feeds on living or dead organic material.

 

continental climate

The type of climate found inland on large continental areas where it is not subject to ameliorating maritime influences. As such, a continental climate is characterized by more pronounced extremes between summer and winter, with summers being hotter and winters colder than in other climates. It is also charactarized by relatively low rainfall amounts and humidities.

 

continental drift

More later.

 

continental rise

More later.

 

continental shelf

Much more later.

 

continental slope

The relatively steep slope usually found between the continental shelf and the abyssal plain. Continental slopes range from 3 to 6 deg. in slope (with 4 deg. being about average), range in depth from 100-300 m to 1400-3200 m, range in width from 20-100 km, and occupy about 8.5% of the ocean floor if the 2000 m contour is taken as the deeper border. The continental shelf and slope are said to comprise the continental margin.

 

continental shelf wave

To be completed.

 

Continental Water Boundary

In physical oceanography, a frontal region in the Southern Ocean located at around 61-62 deg. S that separates the Continental Zone to the south and its separate water mass of uniform temperature and low salinity in the upper 500 m from the Antarctic Zone to the north. See Tomczak and Godfrey (1994), pp. 76. This is also known in the Weddell Sea region as the Weddell Gyre Boundary.

 

Continental Zone

In physical oceanography, a region in the Southern Ocean between the Southern ACC Front and the continent of Antarctica. It is characterized hydrographically by a water mass of uniform temperature and low salinity in the upper 500 m. The CZ is one of four distinct surface water mass regimes in the Southern Ocean, the others being (to the north) the Antarctic Zone (AZ), the Polar Front Zone (PFZ) and the Subantarctic Zone (SAZ). See Orsi et al. (1995).

 

continuous plankton meter

A device used by biological oceanographers to provide continuous qualitative and quantitative records of plankton distribution and patchiness when studying swarms over large areas. The meter is a square or round torpedo-shaped tube about 1 m long that is towed behind a ship underway at full speed. There is a small entrace hole in the front end which leads to a wider tunnel across which a band of silk gauze is stretched. This gauze is slowly wound from one spool to another via a propeller mechanism attached to the outside of the meter, thus being linked to the speed of the meter and therefore the distance it has traveled. Data gathered with the meter is considered supplementary to other types of net tow data gathered separately at individual stations. See Sverdrup et al. (1942).

 

contra solem

A term introduced by V. W. Ekman in 1923 to describe motion turning to the left (right) in the northern (southern) hemisphere, i.e. cyclonic motion. This is the reverse of cum sole.

 

contrail cirrus

A type of cloud hypothesized to form when water vapor within jet aircraft plumes undergoes homogeneous and/or heterogeneous nucleation processes upon which ice particles form and grow. They persist for only a short time if the ambient air is dry, but may last for minutes to hours and spread into linear formations a few kilometers in width and tens of kilometers in width if humid conditions prevail. They also tend to cluster in groups. Various investigations attempting to show a connection between them have at least showed a correlation between increased use of jet fuel in some regions and the average annual number of clear days. See Liou (1992).

 

convective adjustment

In the numerical modeling of ocean circulation, this is a process wherein, after each time step, the vertical potential density gradient is calculated and, if densier water anywhere overlies lighter water, the densities are mixed such that a state of either a neutral or slightly positive stability is created. This process numerically mimics the convective overturning processes observed and inferred in the real ocean at locations such as the Weddell Sea, although the real process takes place at spatial scales on the order of a kilometer or less while the model resolution is such that the spacing between grid points is usually much greater than this.

 

convective available potential energy

A quantity, abbreviated CAPE, used by meteorologists to estimate the possible intensity of thunderstorms. CAPE is an integral of the total energy of an air parcel warmer than the ambient environment as it rises from the level of free convection (LFC) to the limit of convection (through the region of conditional stability) in an environment conducive to storm development. It is calculated as

where is the parcel temperature, the temperature of the environment and g gravitational acceleration. An estimated maximum updraft velocity is obtained by equating this measure of potential energy to kinetic energy, thus obtaining a measure of storm strength.

 

convective precipitation

One of the two clearly distinguishable types of precipitation, the other being stratiform. Convective precipitation falls from cumulus and cumulonimbus clouds, and is defined as a precipitation process in which vertical air motion equals or exceeds the typical fall speeds of ice crystals and snow. The precipitation particles originate and grow not far above the base of the cloud at the time of cloud formation, and the growth mechanism is that of accretion of liquid water. The strong convective updrafts condense large amounts of liquid water which facilitates the rapid growth of the particles until they reach a size sufficient to overcome the upward force of the wind and fail as rain. This process takes significantly less than an hour to complete. See Houze (1993), pp. 197-200.

 

convergence

In numerical modeling, a numerical computational scheme is said to be convergent is the solutions to the discrete algebraic equations created by the process of discretization approach the solutions of the original continuum differential equations as the spacing in the computational grid is shrunk to zero. Thus convergence deals with relations between solutions of equations in their continuum versus discrete forms, as opposed to consistency.

 

CONVEX

Acronym for CONtrol Volume EXperiment.

 

conveyor belt

A simple model of a closed global thermohaline interbasin exchange circulation scheme introduced by Broecker (1987), Broecker (1991), and Gordon (1986). Cold and salty deep water formed in the Norwegian/Greenland Sea (called NADW) flows southward as a deep current where around 30% is transported via the ACC to the Indian and Pacific Oceans. The flow travels northward along the western boundaries of these oceans and upwells in the northern portions. This drives a warm, shallow return flow that travels from the Northern Pacific through the Indonesian Archipelago and the Indian Ocean (gaining the water upwelled there) towards the South Atlantic via the southern tip of Africa. There it is joined by the remaining 70% that mixed with AAIW and returned to the South Atlantic via the Drake Passage. A general northward flow returns the water to the North Atlantic. The regions of deep water formation around Antarctica form AADW which flows under and mixes with the NADW, forming another component in the mixture. This is a simple (and to some an overly simplistic) view of the thermohaline circulation, but it is useful as a first order description. A more complete and accurate version of the interbasin exchange circulation pattern has been developed.

 

coordinate system

A method by which the position of an object in n-dimensional (where n is usually 2 or 3) space is specified, usually in reference to an origin of the specified coordinate system. A overview of coordinate systems for georeferencing is available on the Web.

 

cooscillating tide

The tide created in an estuary caused by the ocean tide at the entrance to the estuary acting as a driving force. See Officer (1976).

 

COP

Acronym for the Coastal Ocean Program a program office of NOAA that provides scientific information to facilitate the management of coastal resources. More information can be found at the COP Web page.

 

coral bleaching

A phenomena wherein coral reefs bleach as a result of high temperatures or other environmental stresses, e.g. pollution episodes. Observations indicate that since 1979 bleaching episodes have coincided with El Nino war events and suggest that the scale of bleaching since 1979 is unprecedented since 1870. See Goreau and Hayes (1994) and Glynn (1993).

 

coral reef

A limestone structure found in relatively shallow water composed of corals, organisms that secrete limestone foundations to provide structural support and protection. There are three geomorphologically distinct types of coral reefs, fringing reefs, barrier reefs, and atolls, although there are gradations between these types. All these types have the same basic biological structure and result from the same processes of accretion. See Barnes and Hughes (1988).

 

Coral Sea

More later.

 

core layer method

A systematic attempt to apply hydrography to describe the waters of the ocean as developed by Wust and his students in the 1930s. In this method he distinguished between different core layers characterized by maxima or minima in their oxygen, salinity or temperature fields. While of unquestioned descriptive value, this method has some significant limitations. The number of layers that can be identified using this techique is limited, e.g. Wust identified just seven such layers in the North Atlantic, a shortcoming ameliorated by the development of the isopycnal method. Also, these layers were too often uncritically assumed to be the main paths of ocean circulation, an assumption that has been proven to be incorrect on more than one occasion.

 

Coriolis acceleration

An acceleration, the magnitude of which for a particle moving horizontally on the surface of the Earth is where is the angular velocity of the rotation of the Earth, V the vector velocity relative to the Earth's surface, and the latitude. This acceleration is directed perpendicular to the direction of V and to the right (left) in the northern (southern) hemisphere. There are other terms for three-dimensional motion in GFD, but they are generally negligible.

 

Coriolis effect

The denotes the effect of the Coriolis force to deviate a moving body perpendicular to its velocity.

 

Coriolis force

The force which, acting on a given mass, produces the Coriolis acceleration. It is a fictitious force introduced to facilitate the application of Newton's second law of motion to a rotating reference frame.

 

Coriolis parameter

This is defined by

where is the angular velocity of the rotation of the Earth and the latitude. This gives the Coriolis acceleration on a moving particle when multiplied by that particle's velocity.

 

correlogram

A presentation of the degree of autocorrelation in a time series which graphs the autocorrelation coefficient as the ordinate and the lag for each coefficient as the abscissa.

 

cosmogenic

Of or produced by cosmic rays.

 

coupled model

In climate modeling this refers to the combination of an atmospheric GCM with some sort of ocean model rather than the simple specification of SSTs as a lower boundary condition. From simple to complex, the ocean model hierarchy used proceeds from swamp ocean models to slab ocean or mixed-layer models to oceanic GCM models. See Meehl (1992).

 

CPC

Abbreviation for Climate Prediction Center, which provides climate products and services consisting of operational prediction of climate variations, monitoring of the climate system, and development of data bases for determining current global and regional climate anomalies and trends, and analysis of their origins and linkages to the complete climate system. See the CPC Web site.

 

CPOP

Abbreviation for complex principal oscillation pattern, a generalization of the POP concept into the complex domain. Although this was introduced to extend the POP technique to the modeling of standing wave oscillations, it was also found the CPOPs evolve more regularly and with less noise than POPs. Also, prediction skills are significantly stronger than with the POP model. See Burger (1993).

 

craton

A major structural unit of the Earth's crust, generally of igneous and/or metamorphic origin with perhaps a thin layer of sediment, which is no longer affected by orogenic activity. An example is the Canadian Shield. Shield is now used synonymously with craton (or kraton).

 

CREDDP

Abbreviation for the Columbia River Estuary Data Development Program, a project to increase understanding of the ecology of the Columbia River Estuary and to provide information useful in making land and water use decisions. See the CREDDP Web site.

 

Cretaceous

The final period of the Mesozoic era, lasting from 144 to 66.4 Ma. It precedes the Tertiary period of the Cenozoic era and follows the Jurassic period, and is comprised of the Early (144-97.5 Ma) and Late (97.5-66.4 Ma) epochs. It is named from the Greek word for chalk since in Northern Europe and part of the midwestern U.S. it is represented by a unique white limestone known as the Chalk.

 

Cretaceous-Tertiary extinction

This refers to the catastrophic extinction of an estimated 75% of all living species at the end of the Cretaceous (66 Ma). The weight of evidence seems to favor the theory that an asteroid impact was the major cause of this event. Paleontological evidence for other extinction events occuring every 20-30 million years has led to various theories attempting to explain these supposed cyclic extinctions, the best known of which is the Nemesis theory.

 

CRF

Abbreviation for cloud radiative forcing.

 

Croll, James

Needs work.

 

Cromwell Current

More later.

 

cryosphere

That part of the climate system consisting of the ice fields of Antarctica and Greenland, other continental snow and ice fields, sea ice and permafrost. At present the Antarctic ice sheet holds 89.3% of the total global ice mass, with the Greenland ice sheet holding 8.6% and mountain glaciers and permafrost holding 0.76% and 0.95%, respectively. The remaining 0.39% is distributed among seasonal snow and sea ice. See Untersteiner (1984), Hibler and Flato (1992), and Van der Veen (1992).

 

Cryptophyta

A Phylum of phytoplankton.

 

Cryptozoic

An eon comprising the whole of geologic time to the end of the Precambrian era, as opposed to Phanerozoic after that. It is represented by rocks in which evidence for life is only slight and of primitive forms.

 

CRYSYS

Acronym for CRYospheric SYStem, a Canadian interdisciplinary science investigation under the NASA EOS program. The goals of CRYSYS are to develop capabilities for monitoring and understanding regional and North American variations in cryospheric variables, to develop and validate local, regional and global models of climate/cryospheric processes and dynamics, and the assemble, maintain and analyze key historical, operational and research cryospheric data sets. See the CRYSYS Web site.

 

CSIRO

Abbreviation for Commonwealth Scientific and Industrial Research Organization, the chief scientific research organization in Australia. See the CSIRO Web site.

 

CSM

Abbreviation for Climate System Monitoring Project, a WCDMP project to provide CSMP members with information on large-scale climatic fluctuations and to facilitate the interpretation and dissemination of this information. More information can be found at the CSM Web site.

 

CSW

Abbrevation for continental shelf wave.

 

CTD

In oceanography, an abbreviation for Conductivity-Temperature-Depth, an instrument for performing oceanographic measurements. The CTD measures (either directly or indirectly) the three most important oceanographic parameters for describing the distribution of water in the ocean: temperature, salinity, and pressure.

 

CTDO

Abbreviation for Conductivity-Temperature-Depth-Oxygen profiler.

 

CTEI

Abbreviation for cloud top entrainment instability. See Deardorff (1980).

 

CTW

Abbreviation for coastal trapped wave.

 

cum sole

Descriptive of rotation in the same sense as a vector that points toward the sun, i.e. motion turning to the right (left) in the northern (southern) hemisphere, i.e. anticyclonic motion. This term, along with the opposite contra solem, was coined by V. W. Ekman in 1923.

 

cumulus

A type of cloud that is shaped like heaps or piles. It is colored brilliant white in sunlight and dark and flat at the base, and forms at an altitude of approximately 16,000 feet.

 

cumulonimbus

A type of cloud associated with storms and rains. It is heavy and dense with a flat base and a high, fluffy outline, and can be tall enough to occupy middle as well as low latitudes. This type of cloud is formed from about 10,000 to 12,000 feet of altitude.

 

curl

The curl of a vector field is a measure of its rotational motion, i.e. when applied to the velocity vectors of air or water motion, the curl is nonzero if the parcel is spinning. In mathematical terms, the divergence of a vector function is defined by

where is the gradient operator that operates with a vector (or cross) product on the vector field A. See Dutton (1986).

 

CW

(1) In meteorology, an abbreviation for cloud water. (2) In physical oceanography, an abbreviation for Central Water.

 

CWB

In physical oceanography, an abbreviation for Continental Water Boundary.

 

CWC

Abbreviation for cloud water content, comprising both LWC and IWC.

 

Cyanophyta

A Phylum of phytoplankton better known as blue-green algae. They are the most primitive of the phytoplankton and show many affinites with bacteria. They are commonly found in great abundance in shoreline and estuarine environments, although oceanics species are rarer. Reproduction can take place by production of endospores, exospores, or unencysted fragments of filaments.

 

cyclic extinction

There exists persuasive evidence for several major extinction events in Earth history. Analysis of the temporal nature of this record has led some to perceive a cyclic pattern to these extinction events. One causal mechanism advanced to explain this perceived periodicity involves the Nemesis theory.

 

cyclone

An atmospheric pressure distribution in which there is a low central pressure relative to the surroundings. The circulation around the center is anticlockwise (clockwise) in the northern (southern) hemisphere.

 

cyclonic

The direction of rotation around a center of low pressure. This is counter-clockwise in the northern hemisphere and clockwise in the southern. The term originates from the circulation observed around tropical cyclones.

 

cyclostationary

In statistics, this is said of a process evincing periodic correlations.

 

cyclostratigraphy

The study of rhythmic sedimentary sequences.

 

cyclostrophic wind

A theoretically hypothesized wind that would exist, when blowing around circular isobars, as a balance between the pressure gradient and the centrifugal force. The Coriolis force is neglected, and as such this is a useful approximation only in low latitudes, e.g. in tropical cyclones.

 

cyclothem

A series of beds deposited during a single cycle of sedimentation.

 

CZCS

Abbreviation for Coastal Zone Color Scanner, a scanning radiometer with six spectral channels centered at 0.443, 0.520, 0.550, 0.670, 0.750 and 11.5 micrometers and selected to allow measurement of ocean color and temperature, suspended sediment and chlorophyll concentrations, and ocean pollutants. The device resolution is 800 m. This instrument flew aboard the NIMBUS-7 satellite.