Science terms starting with C

1,236 terms

County Warning Forecast Area (CWFA) The area (aggregation of counties, or parishes and sometimes portions of counties, or parishes) served by a WFO for which weather forecast and warning…
Coupled Atmosphere-Ocean Model Same as Coupled Model; in the context of climate modeling this usually refers to a numerical model which simulates both atmospheric and oceanic motions…
Coupled Model In the context of climate modeling this usually refers to a numerical model which simulates both atmospheric and oceanic motions and temperatures and…
Coupled to Radiation Matter, such as charged particles, that is strongly affected by radiation.
Couplet Adjacent maxima of radial velocities of opposite signs.
coupling The phase state in which either two dominant or two recessive alleles of two different genes occur on the same chromosome. Synonym: cis configuration.
covalently-closed circular DNA (Abbreviation: ccc DNA). A DNA molecule in which the free ends have ligated to form a circle. The strands remain linked together even after denaturation.
Covenants Rules and restrictions governing the use of property.
cover Natural or manmade objects on the bottom of lakes, rivers, or impoundments, especially those that influence fish behavior.
Cover crop A crop that provides temporary protection for delicate seedlings and/or provides a canopy for seasonal soil protection and improvement between normal crop…
COW A radioisotope generator system.
Coyote holes Horizontal tunnels in which explosives are packed for blasting a high rock face.
CP4 EPSPS Abbreviation for CP4 5-enolpyruvyl-shikimate-3-phosphate synthase. See: enolpyruvyl-shikimate-3-phosphate synthase.
CPC Climate Prediction Center
cpDNA Abbreviation for chloroplast DNA.
Crack To beat a hand - typically a big hand. You hear this most often applied to pocket aces: "Third time tonight I've had pocket aces cracked."
cracking A reduction of molecular weight by breaking bonds, which may be done by thermal, catalytic, or hydrocracking.
craniosynostosis A birth defect whereby an infant's skull bones are already fused at birth. Because this defect may interfere with the ability of the brain to grow…
Crater A steep-sided, usually circular depression formed by either explosion or collapse at a volcanic vent.
Crawlspace The unoccupied, and usually unfinished and unconditioned space between the floor, foundation walls, and the slab or ground of a building.
Crazing A network pattern of fine cracks in concrete that do not penetrate much below the surface.
Credit Credit generally refers to the ability of a person or organization to borrow money, as well as the arrangements that are made for repaying the loan and…
Credit clearing A mechanism for settling mutual claims that shares among many parties the risk of a company failing to fulfill its contract.
Credit rating Your credit rating is an independent statistical evaluation of your ability to repay debt based on your borrowing and repayment history.
Credit Risk A term used to describe the possibility of default on a loan by a borrower.
Credit Score A number, roughly between 300 and 800, that measures an individual's credit worthiness. The most well-known type of credit score is the FICOÃÂ® score.
Creek A small stream of water which serves as the natural drainage course for a drainage basin of nominal, or small size.
Creep Monster
Creep (rate) Relatively slow movement along a fault. It is sometimes called "seismic creep" to distinguish it from the slumping of rock or soil on slopes (which is…
Creosote A liquid byproduct of wood combustion (or distillation) that condenses on the internal surfaces of vents and chimneys, which if not removed regularly, can…
Crepuscular Rays The alternating bands of light and dark (rays and shadows) seen at the earth's surface when the sun shines through clouds.
Crescents Quarter-moon-shaped (hence crescent) artifacts that may have been in the form of blades, scrapers, or projectile points.
Crest The top surface of the dam. A roadway may be constructed across the crest to permit vehicular traffic or facilitate operation, maintenance, and…
Crest (Top) of Dam The elevation of the uppermost surface of a dam excluding any parapet walls, railings, etc.
Crest elevation (crest of dam, top of dam, dam crest) The elevation of the uppermost surface of a dam, usually a road or walkway, excluding any parapet wall, railing, curb. etc.
Crest Gage A gage used to obtain a record of flood crests at sites where recording gages are installed.
Crest Gate (Spillway Gate) A gate on the crest of a spillway to control the discharge or reservoir water level.
Crest Length The length of the top of a dam from left abutment to right abutment, including the length of spillway, powerhouse, navigation lock, fish pass, etc.
Crest length (length of dam) The distance, measured along the axis or centerline crest of the dam at the top level of the main body of the dam or of the roadway surface on the crest…
Crest of Dam The elevation of the uppermost surface of a dam excluding any parapet wall, railings, etc.
Crest structure Portion of spillway between the inlet channel and the chute, tunnel or conduit, which does not contain gates.
Crest Width The width or thickness of a dam at the level of the crest of the dam. In general, the term "thickness" is used for gravity and arch dams and "width" is…
Crest Width (Top thickness) The thickness or width of a dam at the level of the top of dam (excluding corbels or parapets).
Creutzfeldt-Jakob Disease (CJD) A disease of humans hypothesized to be caused by a prion, or a small protein, which alters the structure of a normal brain protein, resulting in…
Crib Dam A gravity dam built up of boxes, cribs, crossed timbers or gabions, filled with earth or rock.
Cripto Transcription factor expressed by pluripotent stem cells and early embryos.
Criteria air pollutants Six common air pollutants for which National Ambient Air Quality Standards (NAAQS) have been established by the U.S.
Criteria pollutant A pollutant determined to be hazardous to human health and regulated under EPA's National Ambient Air Quality Standards.
Critical Compression Pressure The highest possible pressure in a fuel-air mixture before spontaneous ignition occurs.
Critical Density The density of matter/energy that would just halt the expansion of the universe. The dividing line between a collapsing and an ever-expandinguniverse.
Critical Depth The depth of flow when the Froude number equals one. The depth of flow at which the discharge is maximum for a given specific energy, or the depth at…
Critical discharge The maximum discharge for a given specific energy, or the discharge which will occur with minimum specific energy.
Critical Flow When the Froude number is equal to one, the flow is critical and surface waves remain stationary in the flow. Flow at critical depth.
Critical habitat The specific area within the geographical area occupied by the species at the time it is listed as endangered or threatened.
Critical habitat unit (CHU) Under the Endangered Species Act, critical habitat is defined as "the specific areas within the geographic area occupied by a species on which are found…
Critical height The maximum height at which a vertical or sloped bank of soil will stand unsupported under a given set of conditions.
Critical notices Pipeline issuances that provide information on conditions that affect natural gas scheduling or adversely affect scheduled gas flow.
Critical Rainfall Probability (Abbrev. CRP) - In hydrologic terms, the Probability that the actual precipitation during a rainfall event has exceeded or will exceed the flash flood…
Critical Rainfall Probability (CRP) The probability that the actual precipitation during a rainfall event has exceeded or will exceed the flash flood guidance value.
Critical slope The maximum angle with the horizontal at which a sloped bank of soil or rock of given height will stand unsupported.
Critical velocity The mean velocity when the discharge is critical.
CRN Coronal Rain - In solar-terrestrial terms, material condensing in the corona and appearing to rain down into the chromosphere as observed at the solar…
Crochet In solar-terrestrial terms, a sudden deviation in the sunlit geomagnetic field (H component; see geomagnetic elements) associated with large solar flare…
Crop irrigation requirement Quantity of water, exclusive of effective precipitation, that is needed for crop production. See irrigation requirement.
Crop Moisture Index In 1968, Palmer developed the index to assess short-term crop water conditions and needs across major crop-producing regions.
Crop residue Organic residue remaining after the harvesting and processing of a crop.
Crop root zone The soil depth from which a mature crop extracts most of the water needed for evapotranspiration.
Crop rotation A pattern of changing the crops grown in a specific field from year to year in order to control pests and maintain soil fertility.
Crop subsidy Price support paid by the government to farmers.
Crop tree Usually a conifer tree grown to provide wood products.
Crop water requirement Crop consumptive use plus the water required to provide the leaching requirements.
Cropping pattern The acreage distribution of different crops in any one year in a given farm area such as a county, water agency, or farm.
cross The mating of two individuals or populations. See: cross-breeding.
cross pollination efficiency The ease with which cross pollination can be achieved. Generally measured by the number of hybrid progeny generated per flower pollinated.
cross-breeding Mating between members of different populations (lines, breeds, races or species). See: cross.
Cross-hybridization The hydrogen bonding of a single- stranded DNA sequence that is partially but not entirely complementary to a singlestranded substrate.
cross-over See: chiasma.
Cross-pollination Fertilization of a plant from a plant with a different genetic makeup.
Cross-section Slice of the channel and adjacent valley made perpendicular to the assumed flow.
Cross-sectional area Area of a stream, channel or waterway, usually measured perpendicular to the flow.
Cross-Valley Wind System A thermally driven wind that blows during daytime across the axis of a valley toward the heated sidewall.
Crossing over The exchange of DNA sequences between chromatids of homologous chromosomes during meiosis.
crossing-over unit See: recombination fraction.
Crown The base of the stem of cereals and forage species from which tillers or branches arise. In woody plants, the root-stem junction.
Crown Fire A fire where flames travel from tree to tree at the level of the tree's crown or top.
crown gall A tumorous growth at the base of certain plants characteristic of infection by Agrobacterium tumefaciens.
Crowning Movement of a fire from the understory into the crown of a forest canopy.
CRP Abbreviation for catabolite regulator protein. See: catabolite activator protein.
CRS Console Replacement System for NOAA Weather Radio
Crucial winter range The portion of the winter range to which a wildlife species is confined during periods of heaviest snow cover or that portion of the year-long range which…
Crude oil A mixture of hydrocarbons that exist in liquid phase in underground reservoirs and remain liquid at atmospheric pressure after passing through surface…
Crushed gravel Gravel which has been produced by a machine.
Crushed rock Rock which has been reduced in size by a machine.
Crusher A machine which reduces rocks to smaller and more uniform sizes.
Crustaceans Aquatic animals with hard external skeletons and segmented limbs, belonging to the class Crustacea; include cladocerans, shrimp, crayfish, fairy shrimp…
Crustal spreading center A linear zone in the Earth's crust whose opposite sides are moving away from one another.
cry proteins A class of crystalline proteins produced by strains of Bacillus thuringiensis, and engineered into crop plants to give resistance against insect pests.
Cry1A A protein derived from the bacterium Bacillus thuringiensis that is toxic to some insects when ingested.
cryobiological preservation The preservation of germplasm resources in a dormant state by storage at ultra-low temperatures, often in liquid nitrogen.
Cryogenic At very low temperature.