Data Collection Platform (DCP)(DCP)An electronic device that connects to a river or rainfall gage that records data from the gage and at pre-determined times transmits that data through a…
Data Management Facility (DMF)(DMF)Manages ARM datastream and provides for the collection, processing, analysis, and delivery of ARM data.
Data Management System (DMS)(DMS)Controls the data flow and minimizes data loss. Its primary functions are data collection, storage, and processing.
data object descriptionThe basic information, definitions, and metadata required to process "raw" measurement data to standard NetCDF files.
Data PointIn the context of hydrologic observations, a location on a river/stream for which observed data is input to RFC or WFO hydrologic forecast procedures, or…
Data Quality Assessment Report (DQAR)(DQAR)An assessment report issued by the Data Quality Office and/or instrument mentors based on a data quality inspection.
Data Quality Problem Report (DQPR)(DQPR)An ARM infrastructure problem report issued to site operators by the Data Quality Office, instrument mentors, and/or site scientists to report a problem…
Data Quality ProgramRun by the ARM Program Data Quality Office to help coordinate the continued evolution and implementation of efforts to assure the quality of the data…
Data Quality Report (DQR)(DQR)Used to identify and document problems with ARM systems, physical infrastructure, or instruments.
Data warehouseA collection of databases, data tables, and mechanisms to access the data on a single subject.
DATACOLThe Software System that supports RFC gateway functions.
datastreamSimilar files that are in a time-sequenced series.
DataWebDataWeb is an electronic presentation of the Bureau of Reclamation's Project Data book and contains historical, statistical, and technical information on…
dATPAbbreviation for deoxyadenosine 5'-triphosphate. dATP is required for DNA synthesis since it is a direct precursor molecule. See: adenosine, adenylic acid.
datumAny level surface taken as a plane of reference from which to measure elevations.
DaughterA nucleus formed by the radioactive decay of a different (parent) nuclide.
DawnSame as Civil Dawn; the time of morning at which the sun is 6 degrees below the horizon.
Day LengthDuration of the period from sunrise to sunset.
Day-ahead marketsForward markets for electricity to be supplied the following day. This market closes with acceptance by the independent system operator, power exchange…
Day-night average noise levelTwenty-four-hour average noise level, obtained after the addition of a 10-dB penalty for environmental noise occurring from 10 p.m. to 7 a.m.
Day-Second FeetOften abbreviated as SDF. See Second-Day Feet.
DaylightingThe use of direct, diffuse, or reflected sunlight to provide supplemental lighting for building interiors.
Daytime mean rural background levelDaytime (7 a.m. to 10 p.m.) average sound level in the rural environment, from all sources other than a particular noise that is of interest.
dBZNondimensional "unit" of radar reflectivity which represents a logarithmic power ratio (in decibels, or dB) with respect to radar reflectivity factor, Z.
DCP(Data Collection Platform) In hydrologic terms, an electronic device that connects to a river or rainfall gage that records data from the gage and at…
dCTPAbbreviation for deoxycytidine 5'-triphosphate. dCTP is required for DNA synthesis since it is a direct precursor molecule. See: cytidine, cytidylic acid.
DDDirect Damage. This is a spell that does all of its damage in one hit rather than spreading its damage over time.
DDSA rare disorder that causes kidney failure before age 3, abnormal development of the sexual organs, and, in most cases, Wilms tumor (a type of kidney…
De Facto MPADelineated areas of the marine environment where human access is restricted or where specific activities or uses are regulated for reasons other than…
de-differentiationThe process, in response to wounding and in tissue cultures, by which plant cells can become unspecialized and start to proliferate by cell division to…
De-energize(d)To disconnect a transmission and/or distribution line; a power line that is not carrying a current; to open a circuit.
de-ionized waterWater from which most salts have been removed - with varying degrees of efficiency - by ion exchange.
Death phaseThe final growth phase, during which nutrients have been depleted and cell number decreases. (See Growth phase).
Debris CloudA rotating "cloud" of dust or debris, near or on the ground, often appearing beneath a condensation funnel and surrounding the base of a tornado.
Debris fanSloping mass of boulders, cobbles, gravel, sand, silt and clay formed by debris flows at the mouth of a tributary.
Debris flowA mixture of water-saturated rock debris that flows downslope under the force of gravity (also called lahar or mudflow).
Debris flow fansAlluvial fans prone to debris flows; a mixture of water and debris, such as mudslides, mudflows, or debris avalanches.
Debt financingProviding capital by selling bonds, bills, or notes to individuals or institutions.
DecadalOccurring over a 10-year period, such as an oscillation whose period is roughly 10 years ("Pacific Decadal Oscillation").
Decay (radioactive)The change of one radioactive nuclide into a different nuclide by the spontaneous emission of alpha, beta, or gamma rays, or by electron capture.
DecelerationDecreasing the velocity (of expansion).
deceleration phaseThe phase of declining growth rate, following the linear phase and preceding the stationary phase in most batch-suspension cultures. See: growth phase.
DecibelA unit for expressing the relative intensity of sounds on a scale from zero for the average least perceptible sound to about 130 for the average level at…
Decibel (dB)(dB)A standard unit for measuring the loudness or intensity of sound. In general, a sound doubles in loudness with every increase of 10 decibels.
Decibel, A-weighted (dBA)(dBA)A measurement of sound approximating the sensitivity of the human ear and used to characterize the intensity or loudness of a sound.
Decidual cellsA cellular matrix that first surrounds an implanted embryo and later occupies most of the endometrium.
DeciduousPlants that shed their leaves annually. Not evergreen.
Deciduous treesTrees such as oaks and maples that lose their leaves during part of the year. See coniferous trees.
Decision criteriaSet of formal criteria that is used to determine if an event is threatening and what action to implement.
Decision makersDesignated personnel responsible for interpreting data that has been collected and determining if an event is threatening enough to issue an alert or…
Decision makingThe second of five Early Warning System components consisting of the processes and facilities necessary to translate incoming data about the threatening…
Decision noticeThe written record of a federal agency decision after an environmental assessment.
DeckingSeparating charges of explosives by inert material which prevents passing of concussion, and placing a primer in each charge.
DeclinationThe angular position of the sun at solar noon with respect to the plane of the equator.
Declining Block RateAn electricity supplier rate structure in which the per unit price of electricity decreases as the amount of energy increases.
DecommissioningThe process of removing a power plant, apparatus, equipment, building, or facility from operation.
DecompositionThe process of breaking down organic material; reduction of the net energy level and change in physical and chemical composition of organic material.
DecontaminationThe removal of radioactive contaminants by cleaning and washing with chemicals.
DecouplingA regulatory design that breaks the link between utility revenues and energy sales to encourage utility investment in conservation.
Deed covenantA term used in association with the sale of excess lands. In order for an eligible buyer of excess land to receive Reclamation irrigation water on such…
Deed RestrictionA legally binding restriction on the use, activity, and/or limitation of property rights, recorded at the registry of deeds.
Deep DischargeDischarging a battery to 20 percent or less of its full charge capacity.
Deep percolationThe movement of water by gravity downward through the soil profile beyond the root zone; this water is not used by plants.
Deep Percolation LossWater that percolates downward through the soil beyond the reach of plant roots.
Deep SeepageInfiltration which reaches the water table.
Deep wellA well whose pumping head is too great to permit use of a suction pump.
Deep-cycle batteryA battery with large plates that can withstand many discharges to a low state of charge.
DeepeningA decrease in the central pressure of a surface low pressure system. The storm is intensifying.
deepwateran ocean water mass with relatively uniform temperature, salinity, and density, found near the bottom of the ocean.
defective virusA virus that, by itself, is unable to reproduce when infecting its host cell, but that can grow in the presence of another virus.
deficiency(dih-FIH-shun-see) In medicine, a shortage of a substance (such as a vitamin or mineral) needed by the body.
Deformation ZoneThe change in shape of a fluid mass by variations in wind, specifically by stretching and/or shearing.
Deformed IceA general term for ice which has been squeezed together and forced upwards and downwards in places.
degeneracyThe specification of one amino acid by more than one codon. It arises from the inevitable redundancy resulting from the 64 possible codons encoding only…
degeneration1. Changes in cells, tissues or organs due to disease. 2. The reduction in size or complete loss of organs during evolution.
DegradationProcess wherein the elevation of streambeds, sandbars, and flood plains is lowered by erosion. The opposite of aggradation.
Degree DayA unit for measuring the extent that the outdoor daily average temperature (the mean of the maximum and minimum daily dry-bulb temperatures) falls below…
Degree HourThe product of 1 hour, and usually the number of degrees Fahrenheit the hourly mean temperature is above a base point (usually 65 degrees Fahrenheit)…
dehalogenationThe removal of halogen atoms (fluorine, chlorine, bromine, iodine) from molecules, for example during biodegradation.
dehiscenceThe spontaneous and often violent opening of a fruit, seed pod or anther to release and disperse the seeds or pollen.