Science — page 110 of 132

13,110 terms including subtopics (0 terms filed directly here)

Science terms

slope An inclined surface usually defined by the ratio of the horizontal distance to the vertical distance, i.e. 2:1 (2 horizontal units to 1 vertical unit).
Slope failure The downward and outward movement of a mass of rock or unconsolidated materials as a unit. Landslides and slumps are examples.
Slope Protection The protection of an embankment slope against wave action or erosion.
Slope stability The resistance of an inclined surface to failure by sliding or collapsing.
SLOSH (Sea, Lake and Overland Surges from Hurricanes) - A computer model run by the National Hurricane Center (NHC) to estimate storm surge heights resulting…
Slough A long, narrow stretch of water such as a small stream or feeder tributary off a lake or river.
Slow pyrolysis Thermal conversion of biomass to fuel by slow heating to less than 450°C in the absence of oxygen.
SLP Sea Level Pressure
SLT 1. Slight (as in "slight chance") 2. Sleet
Sludge The mixture of organic and inorganic substances separated from sewage.
Slug Large initial amount. A unit of mass which will undergo an acceleration of 1 foot per second squared when a force of 1 pound is applied to it.
Sluice An opening for releasing water from below the static head elevation.
Sluice gate A gate that can be opened or closed by sliding in supporting guides.
Sluiceway An opening in a diversion dam used to discharge heavy floating debris safely past the dam.
Sluicing A method of compacting soil where the soil is washed into placed with a high velocity stream of water.
Slurry Watery mixture of insoluble matter which is pumped beneath a dam to form an impervious barrier. Cement grout.
Slurry trench A narrow excavation whose sides are supported by a mud slurry filling the excavation. Sometimes used incorrectly to describe the cutoff itself.
SLY Southerly
SM service mark
SMA The Soil Moisture Accounting Model.
Small Craft There is no precise definition for small craft. Any vessel that may be adversely affected by Small Craft Advisory criteria should be considered a small…
Small Craft Advisory (SCA) - An advisory issued by coastal and Great Lakes Weather Forecast Offices (WFO) for areas included in the Coastal Waters Forecast or Nearshore Marine…
Small Craft Advisory for Hazardous Seas (SCAHS) - An advisory issued by coastal and Great Lakes Weather Forecast Offices (WFO).
Small Craft Advisory for Rough Bar (SCARB): An advisory issued by coastal and Great Lakes Weather Forecast Offices (WFO) for specialized areas near harbor or river entrances known as bars.
Small Craft Advisory for Winds (SCAW): An advisory issued by coastal and Great Lakes Weather Forecast Offices (WFO).
Small Craft Should Exercise Caution Precautionary statement issued to alert mariners with small, weather sensitive boats.
Small Hail Technically used to refer to snow pellets or graupel.
small nuclear ribonucleoprotein (Abbreviation: snRNP). A complex of small nuclear RNA and nuclear protein, heavily involved in the post-transcriptional processing of mRNA, especially the…
small nuclear RNA (Abbreviation: snRNA ). RNA transcripts of 100-300 bp that associate with proteins to form small nuclear ribonucleoprotein particles.
Small nuclear RNA (snRNA) Short RNA transcripts of 100-300 bp that associate with proteins to form small nuclear ribonucleoprotein particles (snRNPs), which participate in RNA…
Small power producer (SPP) Under the Public Utility Regulatory Policies Act (PURPA), a small power production facility (or small power producer) generates electricity using waste…
Small Scale Energy Loan Program (SELP) (SELP) In Oregon, a low-cost loan and technical assistance program administered by the Oregon Department of Energy.
Small Stream Flooding Flooding of small creeks, streams, or runs.
Smart Energy Is the use of renewable resources to create electricity and to heat and cool buildings, as well as more efficient use of energy through conservation and…
Smart Growth Well-planned development that protects open space and farmland, revitalizes communities, keeps housing affordable and provides more transportation choices.
Smart Window A term used to describe a technologically advanced window system that contains glazing that can change or switch its optical qualities when a low voltage…
Smog A visible haze caused by particulate matter and ground-level ozone.
Smoke (abbrev. K) Smoke in various concentrations can cause significant problems for people with respiratory ailments.
Smoke Dispersal Describes the ability of the atmosphere to ventilate smoke. Depends on the stability and winds in the lower layers of the atmosphere, i.e.
Smoke Management The use of meteorology, fuel moisture, fuel loading, fire suppression and burn techniques to keep smoke impacts from prescribed fires within acceptable…
Smolts Adolescent salmon 3 to 7 inches long.
Smoothed Sunspot Number An average of 13 monthly RI numbers, centered on the month of concern.
SMW (Special Marine Warning) - A warning product issued for potentially hazardous weather conditions usually of short duration (up to 2 hours) producing…
SN snow
Snag Any standing dead, partially dead or defective tree. A hard snag is composed primarily of sound wood.
Snotel SNOw TELemetry - An automated network of snowpack data collection sites. The Natural Resources Conservation Service (NRCS), formerly the Soil Conservation…
Snow Precipitation that consists of frozen flakes formed when water vapor accumulates on ice crystals, going directly to the ice phase.
Snow Accumulation and Ablation Model A model which simulates snow pack accumulation, heat exchange at the air-snow interface, areal extent of snow cover, heat storage within the snow pack…
Snow Advisory This product is issued by the National Weather Service when a low pressure system produces snow that may cause significant inconveniences, but do not meet…
Snow blink Snow blink (snow sky) A bright white glare on the underside of clouds, produced by the reflection of light from snow-covered surface.
Snow Core A sample of either freshly fallen snow, or the combined old and new snow on the ground.
Snow Cornice A mass of snow or ice projecting over a mountain ridge.
Snow cover Snow cover 1) In general, a layer of snow on the ground surface. 2) The areal extent of snow-covered ground, usually expressed as per cent of total area…
Snow Density The mass of snow per unit volume which is equal to the water content of the snow divided by its depth.
Snow Depth The combined total depth of both the old and new snow on the ground.
Snow Flurries Snow flurries are an intermittent light snowfall of short duration (generally light snow showers) with no measurable accumulation (trace category).
Snow Grains Precipitation consisting of white, opaque ice particles usually less than 1 mm in diameter.
Snow Pack Same as Snowcover; the combined layers of snow and ice on the ground at any one time.
Snow Pellets Precipitation, usually of brief duration, consisting of crisp, white, opaque ice particles, round or conical in shape and about 2 to 5 mm in diameter.
Snow Pillow An instrument used to measure snow water equivalents. Snow pillows typically have flat stainless steel surface areas.
Snow Shower A snow shower is a short duration of moderate snowfall. Some accumulation is possible.
Snow Squall A snow squall is an intense, but limited duration, period of moderate to heavy snowfall, accompanied by strong, gusty surface winds and possibly lightning…
Snow Stake A 1-3/4 inch square, semi-permanent stake, marked in inch increments to measure snow depth.
Snow Stick A portable rod used to measure snow depth.
SNOw TELemetry (SNOTEL) (SNOTEL) An automated network of snowpack data collection sites. The Natural Resources Conservation Service (NRCS), formerly the Soil Conservation Service (SCS)…
Snow Water Equivalent The water content obtained from melting accumulated snow.
Snowboard A flat, solid, white material, such as painted plywood, approximately two feet square, which is laid on the ground, or snow surface by weather observers…
Snowcover Also known as Snow Pack; the combined layers of snow and ice on the ground at any one time.
Snowflake An agglomeration of snow crystals falling as a unit.
Snowmelt Flooding Flooding caused primarily by the melting of snow.
Snowpack The total snow and ice on the ground, including the new snow, the previous snow and ice which has not melted.
Snowstorm Snowstorm Strong wind with snow.
SNP The most common type of change in DNA (molecules inside cells that carry genetic information).
SNR Signal-to-Noise Ratio
snRNA See Small nuclear RNA.
snRNP Abbreviation for small nuclear ribonucleoprotein.
SNW Snowfall
SNWFL Snowfall
SO<sub>2</sub> See Sulfur dioxide
Social disruption Social and psychological dislocation associated with the alteration or breakdown of social life in small rural communities that may occur as a result of…
Social Science The branch of science that studies society and the relationships of individuals within a society.
Social value (psychological value) Concept that the existence of wilderness provides a condition that could allow an individual to achieve control over stressful conditions, thus…
Socioeconomic Relating to social or economic factors or to a combination of both social and economic factors.
Socioeconomics The social and economic conditions in the study area.
Sodic soil Contains sufficient exchangeable sodium to interfere with the growth of most crop plants.
Sodicity The exchangeable-sodium content of the soil. High sodium content.
sodium dodecyl sulphate (Abbreviation: SDS). A detergent used to solubilize protein and DNA from biological materials.
sodium dodecyl sulphate polyacrylamide gel electrophoresis (Abbreviation: SDS-PAGE). A widely employed electrophoretic method for the separation of proteins from biological samples.
Sodium Lights A type of high intensity discharge light that has the most lumens per watt of any light source.
Soffit 1. The exposed underside of any architectural element, especially a roof. 2. The underside of a structural component such as a beam, arch, or recessed…
softwood Generally, one of the botanical groups of trees that in most cases have needle-like or scale-like leaves; the conifers; also the wood produced by such…
SOI The Southern Oscillation Index (SOI) has been developed to monitor the Southern Oscillation using the difference between sea level pressures at Darwin…
Soil Sediments or other unconsolidated accumulations of solid particles produced by the physical and chemical disintegration of rocks, and which may or may not…
soil amelioration The improvement of poor soils. Includes the fungal and bacterial break down of plant organic matter, to form humus; the release of minerals - such as…
Soil Carbon A major component of the terrestrial biosphere pool in the carbon cycle. The amount of carbon in the soil is a function of the historical vegetative cover…
Soil cement A mixture of water, cement, and natural soil, usually processed in a tumble and mixed to a specific consistency, then placed in lifts and rolled to…
Soil classification Systematic arrangement of soils into classes of one or more categories or levels of classification for a specific objective.
Soil compaction Compression of the soil which results in reduced soil pore space (the spaces between soil particles), decreased movement of water and air into and within…
Soil conservation Protection of soil against physical loss by erosion and chemical deterioration by the application of management and land-use methods that safeguard the…
Soil conservation practices See minimal tillage practices.