- C3 plant
Any plant that uses the C biochemical pathway for fixing
which involves the enzyme ribulose-diphosphate
carboxylase. Approximately 95% of the Earth's plant biomass
is accounted for by C3 plants.
Abbreviation for the Center for Clouds, Chemistry and Climate,
an organization whose goal is to develop the theoretical, observational,
and modeling base required to understand and predict the changing
clmiate and chemistry of Earth's atmosphere due to natural causes and
human activities. A major objective is to unravel the role of
clouds in climate and chemistry. C4 is located at the Scripps
Institution of Oceanography. The C4 members designed, implemented,
and analyzed the results of the
C4 Web site.
- C4 plant
Any plant that uses the C biochemical pathway for fixing
which involves the enzyme phospho-enol-pyruvate
carboxylase. Approximately 5% of the Earth's plant biomass
is accounted for by C4 plants, although a number of plants
of importance to humans (e.g. maize) are included in this
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 (1987).
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.
CABEX Web site.
Abbreviation for Commission on Atmospheric Chemistry and Global
Acronym for Complete Atmospheric Energetics Experiment.
Acronym for Chesapeake Area Forecasting System, a
project aimed at providing pilots and boaters in the
Chesapeake Bay with improved water level predictions.
CAFE Web site.
Acronym for Conservation of Arctic Flora and Fauna, an
AEPS program to facilitate the exchange
of information and coordination of research on species
and habitats of flora and fauna in the Arctic. The goals of
the program are to conserve Arctic flora and fauna with their
diversity and habitats; to protect the Arctic ecosystem from
threats; to seek to develop improved conservation management,
laws, regulations and practices for the Arctic; to collaborate
for more effective research, sustainable utilization and conservation;
and to integrate Arctic interests into global conservation fora.
CAFF Web site.
Acronym for CERES/ARM/
GEWEX Exercise, intended to foster the
development of algorithms for the retrieval of vertical
profiles of broadband radiative fluxes from satellite data.
See the CAGEX Web site.
The single age of the
lasting from 1.6 to 0.01 Ma. It is preceded by
the Piacenzian age and followed by
the Holocene epoch.
Of or containing calcium carbonate or another, usually insoluble,
- 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.
Acronym for California Co-operative Fisheries Investigations.
CALCOFI Web site.
- California Current
The eastern limb of the clockwise flowing subtropical gyre in
the North Pacific. This, like the
Peru Current is a region of
upwelling although the winds and therefore the upwelling in
this region are more highly variable. The average (with a
large standard deviation) transport has been estimated at
around 11 Sv. From about October to March the prevailing
winds are southeasterly which causes poleward flow at the
surface over the shelf and even further offshore. This seasonal
flow, reaching a peak speed of 0.2-0.3 m/s in January and February,
is sometimes called the
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 Tomczak and Godfrey (1994).
Acronym for Carbonate ALKalinity, a function of carbonate and
bicarbonate ion concentration.
Acronym for Circumpolar Active Layer Monitoring program, an
IPA project for actively monitoring
changes in the thickness of permafrost layers to help in the
detection of climate change.
A French program to monitor the Azores front and the flow of
meddies 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.
The earliest period of the
Paleozoic era, lasting from 570 to 505 Ma and
preceding the Ordovician period. It is
comprised of the Early (570-540 Ma), Middle (540-523 Ma), and
Late (523-505 Ma) epochs.
Named after the Roman name for Wales, the strata of this period
contain the oldest system of rocks in which abundant fossils are
usable for dating and correlation. Most invertebrate groups are
present with trilobites and brachiopods most numerous.
- Camotes Sea
A small sea within the Visayan Islands that comprise the middle
portion of the Philippines. It is centered at about
124.5 E and 10.5 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.
Acronym for Chlorfluorocarbon Alternatives Monitoring Project,
a program of the NOAA CMDL
facility to monitor atmospheric levels of compounds used as
replacements for chlorfluorocarbons, methyl chloroform, and carbon
CAMP Web site.
The fifth of six ages in the
Late Cretaceous epoch, lasting
from 84.0 to 74.5 Ma. It is preceded by
the Santonian age and
followed by the Maastrichtian age.
- Canadian Arctic Archipelago
See Collin and Dunbar (1964).
- Canadian Hydrographic Service
An organization that produces hydrographic maps of Canadian
coastal and inland waters for shipping and recreational
CHS Web site.
- Canadian Institute for Climate Studies (CICS)
A nonprofit Canadian corporation created to further the
understanding of the climate system, its variability and
potential for change, and the application of that understanding
to decision making in both the public and private sectors.
It is located on the campus of the University of Victoria
in British Columbia, and puts out an electronic newsletter called
``The Climate Network.''
CICS Web site.
- 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).
- Canary Current
Acronym for Carbon and Nitrogen Cycling in Forest Ecosystems.
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).
1. Abbreviation for
convective available potential energy.
2. Acronym for Circumpolar Arctic PaleoEnvironments.
Acronym for Convective and Precipitation/Electrification
- Cape Basin
An ocean basin located to the west of South Africa at about
35 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 Verde Basin
An ocean basin located at about 15 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).
- capillary wave
A wave on a fluid interface for which the restoring force is
Acronym for Center for Analysis and Prediction of Storms, an
NSF Science and Technology Center at the University of Oklahoma.
Its mission is to demonstrate the practicality of small-scale
numerical weather prediction with an emphasis on deep
CAPS Web site.
Acronym for Carbon Dioxide Intercalibration Experiment.
- 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
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
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).
- carbon dioxide fertilization
A probable feedback effect of the terrestrial
biosphere-atmospheric carbon system where elevated levels of
CO2 increase the productivity of natural ecosystems. This would
cause more CO2 to be stored in woody tissue or soil organic matter
and thus serve as a negative feedback on the atmospheric CO2
increase. This is also known as the fertilization effect.
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
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).
The penultimate period of the
Paleozoic era, lasting from 360 to 286 Ma.
It precedes the Permian period and
follows the Devonian period, and is comprised of
the Early (360-320 Ma) and Late (320-286 Ma) epochs which coincide with,
respectively, the Mississippian and Pennsylvanian sub-systems into which
it is also divided. It is so named due to the widespread occurrence of
carbon in the form of coal in layers of this period.
Acronym for Climate and Research Directorate, the research arm
of the Atmospheric Environment Service, one of the components
of Environment Canada, a department of the Canadian federal
government. This directorate responds to a number of major
issues of concern to Canada under the overriding concept of
sustainable development, including such topics as atmospheric
change, toxics, and biodiversity.
CARD Web site.
Acronym for the Comprehensive Aerological Reference Data Set, a
DOE and CGCP program providing a high
quality global upper air database containing daily rawinsonde
observations from 1948-1990. This also contains an upper air
station history for 2400+ stations. See the
CARDS Web site.
- Caribbean Current
- Caribbean Sea
Much more later.
Acronym for Caribbean Coastal Marine Productivity, a
Acronym for Marine Pollution Monitoring Program in the
Caribbean, an IOCARIBE program.
- 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).
Acronym for Cloud and Radiation Testbed, a DOE network.
The science of mapmaking. A separate glossary of
is available on the Web.
1. Abbreviation for Commission for Atmospheric Sciences.
2. Abbreviation for Canopy Air Space.
Acronym for Coordinated Air-Sea Experiment.
Acronym for Cooperative Atmosphere-Surface Exchange Study, an
NCAR MMM site that
is being established to enable scientists to observe, understand,
and model linkages among the atmosphere, hydrosphere and terrestrial
biosphere on time scales from minutes to years. The CASES site
is located in the upper Walnut River watershed north of Winfield,
Kansas within the ARM/CART
research area. The goals of this study include: (1) to quantify
the exchange of energy, moisture, and trace chemical species that
link the earth and its vegetation to the atmosphere on a variety
of space and time scales; (2) to develop techniques to properly
represent these linkages in numerical models; (3) to identify the
relative importance of these linkages to atmospheric, hydrospheric,
and biospheric processes; and (4) to examine applicability to
similar biomes worldwide.
CASES Web site.
- Caspian Sea
See Zenkevich (1957) and Zenkevitch (1963).
Acronym for Canadian Atlantic Storms Program.
See Stewart et al. (1987).
Abbreviation for the Cloud and Surface Parameter Retrieval System,
a toolkit for the analysis of data from the
AVHRR satellite sensor carried on NOAA
polar-orbiting satellites. See the
CASPR Web site.
Acronym for the Center for Air Sea Technology, a program whose
emphasis is on application of numerical ocean models and modeling
techniques toward realistic simulation of ocean conditions,
particularly the physical and dynamic state of coastal waters
and semi-enclosed seas. See the CAST Web site.
- Catalan Sea
See Balearic Sea.
Abbreviation for convective boundary layer.
Abbreviatoin for Chesapeake Bay Observing System.
Abbreviation for Commission for the Conservation of Antarctic
Marine Living Resources.
Abbreviation for Canadian Climate Centre, located at Downsview,
1. Abbreviation for Calcite Compensation Depth, defined as the
depth at which the CaCO3 content of sediments reaches 20%.
2. Abbreviation for the Climate Change Detection Project, a
WCDMP project that aims to provide regular
assessments and authoritative statements on the interpretation and
applicability of databases for the detection of climate change on
global and regional scales. See the
CCD Web site for more information.
Abbreviation for the Climate Change and Data and Detection project,
a NOAA OGP program element that provides data and information
management support for a variety of national and international
programs (e.g. GEWEX,
GOALS, etc.), documents the quantitative
character of observed climate variations and changes, and attributes
changes in the observed record to specific climate forcings. See the
CCDD Web page.
Abbreviation for the Centre for Climate and Global Change
Research, located at McGill University in Canada. See the
CCGCR Web site.
Abbreviation for Climatic Change Information Exchange, an attempt to
open and broaden the channels of communication between climate model
owners and users of their information. It is intended to be used
as an electronic library or clearinghouse for climatic change
information. See the
CCIX Web site.
Abbreviation for Canadian Center for Inland Waters.
The abbreviation for the
Community Climate Model, an atmospheric GCM
developed at NCAR. See the
CCM Web site.
Abbreviation for cloud condensation nuclei, particles that serve to
nucleate cloud drops in clouds.
Acronym for Cooperative Convective Precipitation Experiment.
Abbreviation for Clouds in Climate Program, an
NCAR program currently focuses on tropical
convection, although it will eventually encompass other aspects of
clouds in climate research.
CCP Web site.
Abbreviation for the Canada Center for Remote Sensing, a national
center responsible for the acquisition of remotely sensed data and for
the development of remote sensing applications and related methodologies
and systems. See the
CCRS Web site.
Abbreviation for the Center for Climate System Research, located
at the University of Tokyo.
Abbreviation for Coordinating Committee for the World Climate
Program, a WMO committee.
Climate Diagnostics Center.
Acronym for the Climate Dynamics and Experimental Project, a NOAA
OGP initiative to establish a program for quantitative predictions
and reliable assessments of global climate change and its regional
implications on time scales of seasons to a century. See the
CDEP Web page.
Abbreviation for Cloud Depiction and Forecast System.
Acronym for Carbon Dioxide Information and Analysis Center, an
archive at ORNL
containing data pertaining to atmospheric and climate
CDIAC Web site.
Abbreviation for Circumpolar Deep Water.
Acronym for Centro Argentino de Datos Oceanograficos (i.e. the
Argentine Oceanographic Data Center), established in 1974 to
acquire, control quality, process, and store the oceanographic
data gathered by Argentine institutions. CEADO performs the
functions of an NODC for Argentina and
also operates as the RNODC for the
Southern Oceans, i.e. RNODC-SOC. It was also accredited in
1990 to operate as Specialized Oceanographic Center within
CEADO Web site.
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) and the
CEAREX Web site or the
CEAREX Data site.
Acronym for Coordinated Eastern Arctic Experiment.
Acronym for Coupling, Energetics, and Dynamics of Atmospheric
Regions, an NSF program that maintains a data base of
ground-based observations of atmospheric phenomena (e.g. neutral
atmosphere, aeronomy and ionospheric physics and chemistry)
that occur above
the earth's troposphere. Most of the data are from various
CEDAR Web site.
Acronym for Center for Experiment Design and Data Analysis, a
Acronym for Committee on Earth and Environmental Science.
Abbreviation for the U.S. Climate Extremes Index, the annual average
of five indicators. In all of the following much above or much below
normal are defined as falling within the highest or lowest tenth
percentile of the local, long-term record.
The long-term variation or change of this index represents the tendency
for extremes of climate to either decrease, increase, or remain the
same. See Karl et al. (1995) and
Karl et al. (1996).
- The sum of (a) the percent of the U.S. with maximum temperatures
much below normal and (b) the percent of the U.S. with maximum temperatures
much above normal.
- The sum of (a) the percent of the U.S. with minimum temperatures
much below normal and (b) the percent of the U.S. with minimum temperatures
much above normal.
- The sum of (a) the percent of the U.S. in severe drought (equivalent
to the lower ten percentile) based on the PDSI and
(b) the percent of the U.S. with severe moisture surplus (equivalent to
the upper ten percentile) based on the PDSI.
- Twice the value of the percent of the U.S. with a much greater
than normal proportion of precipitation derived from extreme 1-day
precipitation events (more than 2 inches or 50.8 mm).
- The sum of (a) the percent of the U.S. with much greater than
normal number of days with precipitation and (b) the percent of the
U.S. with much less than normal number of days with precipitation.
- Celebes Sea
Alternate name for the
- celestial equator
The great circle in which the plane of the Earth's equator cuts the
celestial sphere; the primary circle to
which the coordinates, right ascension
and declination are referred.
- celestial latitude
The angular distance of a body north or south of the
- celestial longitude
The arc of the ecliptic intercepted between
the latitude circle and the First Point of Aries. It is measured
positively eastwards from 0 to 360 .
- celestial mechanics
The study of the motions of celestial objects in gravitational fields.
A perturbing subject.
- celestial poles
The two points in which the Earth's axis, extended indefinitely,
cuts the celestial sphere.
- celestial sphere
An imaginary sphere, of indeterminate radius, in which the observer
is the center.
- 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) and
Abbreviation for CCAMLR Ecosystem
- Cenderawasih Bay
A bay on the northern coast of Irian Jaya centered at
approximately 135 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
The first of six ages in the
Late Cretaceous epoch, lasting
from 97.5 to 91.0 Ma. It is preceded by
the Albian age
of the Early Cretaceous epoch and
followed by the Turonian age.
The last of three eras of the
Phanerozoic eon, lasting from 66.4 Ma to present.
It is preceded by the Mesozoic era and consists of
the Tertiary and
- centered statistics
See uncentered statistics.
- centers of action
In meteorology, 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
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).
Abbreviation for Centre for Earth Observation, a European
Community (EC) funded program to advance the use of Earth
Observation (EO) data such as is typically collected with
satellites and airborne sensors.
See the CEO Web site.
Abbreviation for Coastal and Estuarine Oceanography Branch, a
part of the NOS Office of Ocean and Earth
Science responsible for traditional products such as the
U.S. Tide and Tidal Current Tables. It also provides a monitoring
and numerical capability in support of safe navigation and
CEOB Web site.
Acronym for Committee on Earth Observation Satellites, a coordinating
group of national space agencies and others with interest in satellite
data management issues. Its objectives include optimizing
the benefits of spaceborne observations, aiding both its members
and the international user community by serving as a focal
point for international coordination of space-related earth
observations satellites, exchanging policy and international
technology, and addressing issues of common interest across the
spectrum of earth observations satellite missions. See the
CEOS Web site.
- CEOS IDN
Abbreviation for the CEOS International
Directory Network, an international effort to assist researchers
in locating information on data sets in the areas of earth sciences,
space physics, solar physics, planetary science, and astronomy
and astrophysics. The IDN describes data held by university
departments, government agencies and other organizations.
CEOS IDN Web site.
1. 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 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: (1) to measure the vertical structure of the water vapor
greenhouse effect; (2) to measure the effect of cirrus on radiation
fluxes over the equatorial Pacific Ocean; (3) to measure the
east-west gradients of SSTs and the evaporative and sensible
heat fluxes from the sea surface along the equatorial Pacific
Ocean; (4) to measure the east-west gradients of vertical distribution
of water vapor along the equatorial Pacific Ocean; and (5) to
explore the microphysical factors contributing to high albedo
of widespread cirrus layers.
See the CEPEX Web site and obtain
the data at CODIAC.
2. Acronym for Controlled Ecosystems Pollution Experiment, a joint
Canada/US/UK experiment of NSF-IOC/IDOE.
A class of marine invertebrates in the phylum
This class includes the squid, devilfish, cuttlefish,
octopus, nautilus as well as extinct forms such as
Most of these have well-developed eyes and are
predatory, although some blind deep sea forms occur.
Some, such as nautilus, have a well-developed outer shell
although others such as the squid and cuttlefish contain
the shell internally.
Cephalopods are either benthic
or pelagic, with some capable of
living at great depths.
The most notorious creature in this class is the giant
squid or Architeuthis princeps.
All 400 or so species in this class are marine.
- Ceram Sea
See Seram Sea.
Acronym for Clouds and the Earth's Radiant Energy System, an
EOS experiment that will provide a consistent
data base of accurately known fields of radiation and clouds.
The CERES experiment will fly broad band, scanning radiometer
instruments on polar orbiting and low earth orbit included
spacecraft as part of EOS. See the
CERES Web site.
Acronym for the European Center for Research and Advanced Training
in Scientific Computation (Centre Europeen de Recherche et de
Formation Avancee en Calcul Scientifique). More information can
be found at the
CERFACS Web site,
including a link to their
Global Change division.
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
CESNA Web site.
A marine order that includes whales and dolphins.
See Gaskin (1976).
Abbreviation for the Centre d'etude des Environnements Terrestre et
Planetaires, a part of the IPSL. See the
CETP Web site.
Abbreviation for Courant, Friedrichs, and Levy, the discoverers
of a time step limitation for numerical simulations of
partial differential equations.
Abbreviation for Coastal Forecast System, a forecasting project
A Phylum of phytoplankton
that occurs widely in the oceans but is only important in
coastal waters. These are motile organisms with one to three
unequal flagella, and they possess an elastic cuticle which
may either be naked or have lightly silicified or calcified
plates. They may be phototrophic,
phagotrophic according to
circumstances. Reproduction occurs by fission or budding.
Most species contain chlorophyll a with phototrophic species
also having chlorophyll c and fucoxanthin.
- 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).
- Chukotsk Sea
See Chukchi Sea.
Abbreviation for Center for Global Atmospheric Modeling, the
core group of UGAMP who are responsible for
maintaining the UGAMP GCM and related diagnostics for the
rest of UGAMP. See the
CGAM Web site.
1. Abbreviation for the Climate and Global Change Program,
a NOAA project that addresses key elements
of the long-term monitoring and mission-directed research
necessary to improve our understanding and prediction of
climate variability. See the
CGCP Web site.
2. Abbreviation for Canadian Global Change Program.
- cgs system
A system of units based on the centimeter, the gram and the
second as fundamental units. This is usually used in the
sciences to express both fundamental and derived units. Compare
to mks system.
A phylum that includes numerous small holoplanktonic
wormlike animals commonly known as ``arrow worms'' or
``glass worms.'' They are transparent, have eyespots,
a caudal fin, one or two pairs of lateral fins, and strong
chitinous jaws and teeth to capture prey. Their distribution
ranges from the surface to great depths in all parts of
the sea. All thirty known species are marine with
Sagitta being the most common genus.
See Alvarino (1965).
- 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 to
The expedition was led
by Sir Wyville Thompson, with
his chief assistant
John Murray and the expedition's
chemist J. Y. Buchanan also playing
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
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
Acronym for Computer Hardware, Advanced Mathematics, and Model
Physics, a DOE program to rapidly advance
the science of decade and longer time scale climate prediction.
CHAMMP Web site.
A collaborative CHAMMP project between
ORNL, ANL and
NCAR addressing the use of massively
parallel computers for climate modeling. See the
CHAMMPions Web site.
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.
CHAMP Web site.
That which we should be mindful of.
- Chappuis bands
Spectral bands in which solar radiation is absorbed by ozone
in the atmosphere. These are weak absorption bands in the
visible and near-IR regions from about 4400 to
See Liou (1992).
Acronym for Coupled Hydrosphere-Atmosphere Research Model.
The second of two ages in the
Oligocene epoch (coincidental with the
Late Oligocene), lasting from 30.0 to 23.7 Ma. It is preceded by
the Rupelian age and followed by
the Aquitanian age of
the Miocene epoch.
- chemical actinometry
The measurement of broadband
actinic flux by the measurement
of the loss of an absorbing gas in a quartz tube or bulb
exposed to sunlight.
See Jeffries (1995).
- chemical oceanography
Compare to biological,
A species of phytoplankton
that can grow without the presence of light. These can be
either facultative and also be able to grow in the presence of
light or obligate and be completely unable to do so.
Acronym for Chemical Research Applied to World Needs.
- Chile Current
See 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
A warm and dry west wind that occurs on the eastern slope of the
Rocky Mountains. It usually arrives suddenly with a consequent
large temperature rise and rapid melting of snow.
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 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
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.
A Phylum of phytoplankton that
are green algae ranging from unicellular to macroscopic types.
Most species are phototrophic
and the marine forms are mainly in the
nanoplankton range. Some
reproduce by cell division and others asexually by means of
zoospores or autospores. They occur mainly in coastal waters
at temperature latitudes in late summer and autumn.
The number of grams of chloride and chloride equivalent to the
bromide in one liter of sea water at 20 C.
See Riley and Chester (1971).
Abbreviation for Carbon-Hydrogen-Nitrogen analyzer.
Acronym for Center for Hydro-Optics and Remote Sensing, formed
in 1988 at San Diego State University to carry out interdisciplinary
research on bio-optical properties and remote sensing of the
ocean environment. Research topics include analysis of inherent
and apparent optical properties of the ocean, development and
validation of ocean color remote sensing algorithms, oceanographic
analyses of in situ bio-optics and remote sensed ocean color
data, relationships between phytoplankton pigments and spectral
reflectance and absorption by sea water, and relationships between
bio-optical profiles and the photo-adaptive state of
CHORS Web site.
- Chronomeric Standard hierarchy
a system of formally naming intervals of geologic time. This
Chronomeric Standard hierarchy consists of the terms
eon, era, period,
epoch, age and
chron. These terms are capitalized when used
with the names of the intervals to which they refer, e.g.
Campanian Age, etc. This system is used
concurrently with the the geochronologic or geologic time unit
system called the
Stratomeric Standard hierarchy.
A branch of stratigraphy dealing with
time as a correlative factor among rock sequences. Contrast with
Abbreviation for Canadian Hydrographic Service.
Abbreviation for Climate Impact Assessment Division, a part of
See Climate Impact Center.
Acronym for Cooperative Investigation of the Caribbean and
Adjacent Regions, an IOC Coordination
Acronym for Center for International Climate and Energy Research,
located in Oslo, Norway. CICERO was created to perform research
in the areas of technology, the natural sciences, economics, law
and politics that is needed to give policy-makers the best
possible information on which to base decisions affecting the
CICERO Web site.i
Canadian Institute for Climate Studies.
Acronym for CEPEX Integrated Data System, a system
to provide easy and uniform access to all the observations from
CEPEX. See the
CIDS Web site.
Acronym for Consortium for International Earth Sciences Information
Network, a private, nonprofit corporation with members from leading
universities and non-government research organizations established
in 1989 to further the interdisciplinary study of global
environmental change. CIESEN is agency-neutral and specializes
in the access and integration of physical, natural, and
socionomic information across scientific disciplines.
CIESIN Web site.
Cooperative Institute for Arctic Research.
Cooperative Institute for Limnology and Ecosystems
Abbreviation for the Center for Marine Research at the
Rudjer Boskovic Institute (IRB) in Zagreb, Croatia.
CIM Web site.
Acronym for Centro de Investigaciones del Mar y la Atmósfera (the
Center for Sea and Atmosphere Research), a research center located
at the University of Buenos Aires in Argentina. It was created
in 1987 as a laboratory associated with the Department of
Atmospheric Sciences and has the objective of expanding the
understanding of the physical processes that control and
determine the behavior of the atmosphere and the ocean.
CIMA Web site.
Acronym for Cooperative Institute for Marine and Atmospheric
Cooperative Institute for Mesoscale Meteorological
Abbreviation for Cooperative Institute for Marine Resources
Acronym for chemical ionization mass spectrometer.
Abbreviation for the Cooperative Institute for Meteorological
Satellite Studies, located at the
SSEC at the University of Wisconsin. See the
CIMSS Web site.
Cooperative Institute for Research in the
- 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 S and
having a temperature of 39.5 F, the sun warms the
sea to temperatures above this mean temperature such that
at 45 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 F. Similarly, the mean temperature line descends
to the south of the circle where it exists at a depth of
750 fathoms at 70 S, above which the temperature decreases
to a surface minimum of 30 F. The latitude of the
circle corresponds closely to the mean position of what is
now known as the
thus leading to Ross identifying an important oceanic feature
for the wrong reasons. The figure of 39.5 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 F due
to pressure distortion effects on his thermometers.
See Deacon (1971).
Cooperative Institute for Research in Environment Science.
A type of cloud composed of ice crystals and shaped in the form
of layers. It is formed at an altitude of approximately
A type of cloud composed of ice crystals and shaped in the form
of heaps or piles. It is formed at an altitude of approximately
A type of cloud composed of ice crystals and shaped in the form of hairlike
filaments. It is formed at an altitude of approximately
See conditional instability of the second kind.
Acronym for Chemical Instrumentation Test and Evalutation, a field
program of the NASA GTE. The CITE missions
focused on the evaluation ofthe ability of airborne instrumentation
to measure key tropospheric constituents. The first two, CITE 1 and
CITE 2, evaluated instruments for measurements of carbon monoxide (CO),
the hydroxyl radical (OH), nitric oxide (NO), nitrogen dioxide (NO2),
nitric acid (HNO3), and peroxyacetyl nitrate (PAN), with CITE 2
also including an emphasis on questions related to the abundance
and partitioning among the major members of the odd nitrogen family.
CITE 3 emphasized the major sulfur species in the troposphere,
evaluating instrumentation for measurement of sulfur dioxide (SO2),
hydrogen sulfide (H2S), carbon disulfide (CS2), dimethyl sulfide (DMS),
and carbonyl sulfide (COS) as well as addressing questions related to
the abundance and photochemistry of these species.
See Beck and et al. (1987) (CITE 1),
Hoell and et al. (1990) (CITE 2), and
Hoell and et al. (1993) (CITE 3).
A group of organisms believed to have
evolved from a common ancestor.
The systematic classification
of groups of organisms on the basis of the order of their assumed
divergence from ancestral species.
A method of graphing the evidence of the most probable evolutionary
relationships between organisms by delineating the branching
sequences in an evolutionary tree.
They are statements of general
pattern testable by applying more data and are useful for the
analysis of biogeographic
history. This is one of two types of
See Nelson and Platnick (1981).
Acronym for the Cryogenic Limb Array Etalon Spectrometer, a
UARS instrument used to measure
temperature profiles and concentrations of ozone, methane, water
vapor, nitrogen oxides, CFCs and other important species in the
atmosphere. CLAES infers the amounts of gases in the stratosphere
from the measurement of the unique infrared emission features
associated with each gas. CLAES has a resolving power of about
4000 and is operated over the wavelength range
from 3.5 to 12.9 microns.
It achieves high spectral resolution and sensitivity by combining
a telescope with an infrared spectrometer and solid state detectors.
The entire instrument is cryogenically cooled to prevent its own
thermal infrared emissions from interfering with the measurement
of weak atmospheric signals.
The measurements are used to study the photochemical,
radiative and dynamical processes taking place in the
CLAES Web site.
A marine invertebrate of the phylum Mollusca
and the class Pelecypoda.
Related animals include oysters and mussels.
1. Acronym for Canadian Land Surface Scheme, an LSP.
See Verseghy (1991) and Verseghy et al. (1993).
2. Acronym for cross-chain LORAN atmospheric
Descriptive of a rock or a sediment consisting mainly of broken
fragments derived from preexisting rocks or minerals that have
been transported a large distance from their place of origin.
Aeolianites consist of clastic material.
See Sellwood and Price (1994).
- Clausius-Clapeyron equation
An equation expressing rate of change of the
saturation vapor pressure
with temperature. It is given by
where is the saturation vapor pressure, T the
temperature, the latent heat of vaporization,
the specific volume of the vapor phase, and
the specific volume of the water phase. This
is given approximately by
where t is the temperature in degrees Celsius.
- CLAW hypothesis
- Clementsian school
One of two major schools of thought in
in the first half of the twentieth century, the other
This school, based in the USA, identified succession as having
the primary role in determining the character of communities.
In this view the `association' was the final stable or semi-stable
climax community and placed emphasis on the dominants. The climax
was assumed to represent the response of plants to the prevailing
climatic conditions, and each climatic type would induce an
appropropriate climax community. This is known as the
monoclimax hypothesis. This school uses a deductive methodology.
See McIntosh (1978).
Acronym for CLoud Experiment OberPfAffenhofen TRAnsports,
an experiment conducted in summer 1992 in Southern Germany.
The project goal was to quantify elements of the
on a regional scale in dependence upon precipitation
events and the vegetation state. Other goals were to describe
the mechanisms that force the organization of
deep convective systems,
to compare theories and observations of atmospheric depositions,
and to test and compare observational methods from platforms
on the ground, on aircraft and in space.
See Meischner et al. (1993).
Acronym for CLImate COMputing which, along with
is a WCDMP project to coordinate the
implementation, maintenance and upgrading of automated climate data
management procedures and systems in WMO member countries. CLICOM
is a system for the collection, quality control and archiving of
climate data and the production of climate applications products.
INFOCLIMA is a system developed to provide information on climate
data sets which are available in various services and institutions
as well as information about observing station networks and National
Climate Centers. See the
CLICOM/INFOCLIMA Web site.
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).
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 Agenda
A proposal for an integrating framework for international
climate-related programs, prepared at the request of the
participants at the Intergovernmental Meeting on the World
Climate Program (IGM-WCP) held in Geneva in April 1993.
It addresses worldwide climate-relate disues and provides
a framework within which governments, international organizations
and non-government organizations can plan their own contributions
to national and international climate-related programs, allocate
financial and human resouces appropriately, and benefit from the complementary
and coordinate activities being undertaken in other nations. It is
primarily addressed to governments and outlines a program that will
provide a cost-effective way to respond to their obligations
arising from international agreements as well as their national
needs for social and economic development.
There is an online copy of the complete document at
the CICS Web site.
- climate change
This is defined by the United Nations Convention on Climate
Change as ``change of climate which is attributed directly or
indirectly to human activity that alters the composition of the
global atmosphere and which is in addition to natural climate
variability observed over comparable time periods.''
This definition deliberately introduces the concept of a
difference between changes in climate that include the effects
of anthropogenic increases in greenhouse gases and changes that
would occur otherwise.
Other definitions of climate change are often used, both
colloquially and scientifically, and may include natural
fluctuations, anthropogenic fluctuations, or both. Distinctions
are also sometimes made between local and global climate
change or short- and long-term climate change. A careful
perusal of the context in which it is used should usually
yield the definition if not offered.
See Houghton and Filho (1995).
- Climate Diagnostics Center (CDC)
A part of the NOAA ERL
network whose mission is performing climate diagnostic studies on
a variety of datasets to provide an understanding of the nature
and causes of climate variability on time scales of months to
centuries. See the
CDC Web site.
- 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
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
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.
- Climate Impact Center (CIC)
A research center located at Macquarie University in Sydney, Australia
whose mission is to study the impacts of climatic variability and
climatic change on Australia and its neighboring countries in the
Asia-Pacific region. See the
CIC Web site.
- Climate Monitoring and Diagnostics Laboratory (CMDL)
A part of the NOAA ERL
network which conducts research to measure atmospheric constituents
and assess climate fluctuations on a variety of time scales.
CMDL Web site.
- climate-physiology-vegetation model
A climate-vegetation model with
an additional level of complication. The physiological
responses of individual species of plants are included with
the climatic variables to model the process of plant competition
and succession to predict the steady-state vegetation expected
under given climatic conditions. An example is the
- climate space
In pollen data analysis, this is a space created by plotting
pollen data with respect to axes of the warmest and coldest
month mean temperatures of the geographical location at which
the pollen data was obtained. An isoline drawn on such a graph
depicts a surface, the elevation of which at any point in climate
space reflects abundance of the pollen taxon.
This surface is called the pollen-climate response surface for
that taxon with respect to those climate variables.
- climate-vegetation model
See bioclimatic classification scheme.
- climatic optimum
A period, lasting from about 5000 to 2000 B.C. when average
temperatures are hypothesized to have reached a higher level,
probably on a world-wide scale, than in the last million
- climax vegetation
Vegetation which, if left undisturbed, will eventually attain a
steady state constrained by prevailing conditions in the
environment (climate, soil, animals, relief, parent material).
Acronym for Climatic Extremes of the Past.
Acronym for the Climate Visualization system, an interactive
graphing tool designed to allow visual browsing of the data
available on-line at the NCDC. See the
CLIMVIS Web site.
Acronym for the WCRP's study of
Climate Variability and Predictability,
scheduled to run from 1995-2010. It focuses on the variability
and predictability of the 'slow' climate system, i.e. those
physical processes working on seasonal, interannual, decadal,
and centennial time scales. CLIVAR is complementary to the
See McPhaden (1995) and the
CLIBAR Web site.
Acronym for Climate Information and Prediction Service,
a WMO project whose ultimate goal is
to provide the best possible climate information, including
expections of future conditions, to improve economic and
social decisions, reduce risks, and improve economic vitality
as well as the quality of life. Specific objectives include
stimulating the use of sector-specific climate information
and prediction services, facilitating the development of a
network of regional and national climate centers, and actively
supporting interdisciplinary and user-oriented research
CLIPS Web site.
- cloud absorption anomaly
A discrepancy between cloud absorption of solar radiation as inferred
from aircraft radiation and that simulated by models. Measurements
yield a value for R, the ratio of the short-wavelength cloud radiative
forcing (CRF) at the Earth's surface to that at the top of the
atmosphere (TOA), of about 1.5, whereas radiative-transfer models
produced R values of around 1.0.
It is not as
yet certain whether this is a real phenomenon or an aberration
stemming from uncertainties in either aircraft flux observations
or input parameters for radiative-transfer modeling.
- cloud ceiling
The height above ground to the bottom of a cloud.
- cloud classification
A system for classifying clouds based on the system proposed by
Luke Howard, a London pharmacist, in 1803. Howard divided clouds
into three fundamental forms: stratus (sheet or layer clouds),
cumulus (heaped-up clouds), and cirrus (fibrous or tufty clouds).
The form nimbus was also added to indicate a rain cloud, but is
now used only in composite forms, e.g. cumulonimbus. The prefix
alto- indicates clouds with bases in the middle
troposphere, well away from the immediate
influence of the ground.
Clouds are also classified into the height-based categories of
low (up to 2 km), medium (2 km to 6 km), and high (above 6 km),
with examples in each category being, respectively, cirrus,
altocumulus, and stratus. The official International
Classification scheme assigns a number to nine types of clouds.
These are (ranging from high to low altitude types): (0) cirrus,
(1) cirrocumulus, (2) cirrostratus, (3) altocumulus,
(4) altostratus, (5) nimbostratus, (6) stratocumulus,
(7) stratus, (8) cumulus, (9) cumulonimbus.
A pictorial guide to the various cloud types can be found
University of Illinois Cloud Catalog.
- cloud forcing
The difference between the radiation budget components for average
cloud conditions and cloud-free conditions. Roughly speaking,
clouds increase the albedo from 15 to
30%, which results in a reduction of absorbed solar radiation
of about 50 W/ . This cooling is offset somewhat by the
greenhouse effect of clouds which
reduces the OLR by about 30 W/ , so the
net cloud forcing of the radiation budget is a loss of about
20 W/ . Were the clouds to be removed with all else remaining
the same, the Earth would gain this last amount in net radiation
and begin to warm up.
See Hartmann (1994).
- cloud fraction
In the numerical modeling of climate processes, the atmosphere
is discretized as a collection of 3-D grid boxes. The average
effects of the physical processes occuring throughout each entire box
are represented by a calculation at one point at the center
of each box. One parameter needed for the calculations is the
horizontal extent of clouds in each box that can absorb and reflect
solar radiation. In the real world counterpart of each box
clouds are usually irregularly distributed throughout the entire
box with there being both clear and cloudy areas. A minimal
estimate of their collective effective is the cloud fraction,
a single number that estimates the percentage of the horizontal
area of the box that contains clouds. The clouds also don't
all have the same properties, e.g.
optical depth, so it is preferable
and more accurate to obtain a frequency distribution of the
cloud properties in the cloudy regions of the box.
See Wielicki et al. (1995).
- cloud height
A parameter needed in numerical climate models to calculate the
vertical extent of clouds in the atmosphere. This enables the number of
vertical grid boxes over which physical processes pertaining
to clouds must be calculated to be ascertained. See
Wielicki et al. (1995).
- Cloud Liquid Water
The CLW content is defined as the total mass of cloud water in a vertical
column of atmosphere per unit of surface area.
- cloud radiative forcing
The amount by which the presence of clouds alters the top-of-atmosphere
energy budget, this is the difference between the cloud-free radiation
budget climatology and the average over all possible cloud scenario
types. ERBE measurements show the net
effect of clouds on the present climate to be a net cooling of
20 W/m2, with a short wave CRF contributing 50 W/m2 cooling
(via reflection of incoming short wave radiation) and
a long wave CRF contribution of 30 W/m2 warming (the greenhouse
See Hartmann (1993) and
Wielicki et al. (1995).
- cloud seeding
Dropping silver iodide crystals or dry ice into selected clouds to
simulate ice crystal formation and induce precipitation.
See Cloud Liquid Water.
Acronym for Coastal Marine Automated Network, a NWS
Climate Monitoring and Diagnostics Laboratory.
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.
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.
CMIP Web site.
Abbreviation for Commission for Marine Meteorology, a
Coastal Mixing and Optics Project.
Abbreviation for Center for Meteorology and Physical Oceanography,
a part of the Depart of Earth, Atmospheric, and Planetary Sciences
at MIT that oversees the graduate programs in atmospheric science
and physical oceanography. The physical oceanography program is
conducted in cooperation whith WHOI.
CMPO Web site.