SwaleA low place in a tract of land, usually moister, and often having denser vegetation than the adjacent higher land.
Swamp CoolerA popular term used for an evaporative cooling device.
SwapsAn exchange of streams of payments over time according to specified terms. A common type is a fixed-for-floating swap, in which one party agrees to pay a…
Swarm (seismic swarm)A localized surge of earthquakes, with no one shock being conspicuously larger than all other shocks of the swarm.
SWDOn a buoy report, Swell Direction is the compass direction from which the swell wave are coming from.
SWESnow Water Equivalent (the amount of water content in a snowpack or snowfall).
SWEATCasinos who are upset by players winning or having skill are said to "sweat" out their games. Also, a player who is losing and is worried.
SwellIncrease of bulk in soil or rock when excavated.
Swell DirectionThe direction from which the swells are propagating.
Swell pressureThe pressure required to maintain zero expansion.
Swept AreaIn reference to a wind energy conversion device, the area through which the rotor blades spin, as seen when directly facing the center of the rotor blades.
SWHOn a buoy report, swell height is the vertical distance (meters) between any swell crest and the succeeding swell wave trough.
Switching stationFacility equipment used to tie together two or more electric circuits through switches.
SWODY1The Day-1 Convective Outlook, sometimes called the "AC" is a guidance product issued by the Operational Guidance Branch (OGB) unit of the Storm Prediction…
SWODY2The Day 2 Convective Outlook is very similar to the Day 1 Outlook. It is issued only twice a day, at 08Z and 18Z, and covers the period from 12Z the…
SWPOn a buoy report, Swell Period is the time (usually measured in seconds) that it takes successive swell wave crests or troughs pass a fixed point.
SWSA rare, congenital disorder that affects the brain, skin, and eyes. Abnormal blood vessel growth occurs in the trigeminal nerve in the face and the…
symbiontAn organism living in symbiosis with another, dissimilar organism.
SymbiosisThe close association of two or more dissimilar organisms where both receive an advantage from the association. See Commensalism, Parasitism.
Symmetric Double EyeA concentrated ring of convection that develops outside the eye wall in symmetric, mature hurricanes.
sympatric speciationThe evolution of new species by population s that inhabit the same or overlapping geographic regions.
sympodialA type of plant development in which the terminal bud of the stem stops growing due either to its abortion, or to its differentiation into a floral…
SynapsisThe pairing of homologous chromosome pairs during prophase of the first meiotic division, when crossing over occurs.
synaptonemal complex(Abbreviation: SC). A ribbon-like protein aceous structure formed between paired homologous chromosome s at the end of the first meiotic prophase.
Synchronous condensersA synchronous machine running without mechanical load and supplying or absorbing reactive power.
synchronous cultureA culture in which the cell cycle is synchronized for the majority of the cells present.
Synchronous DetectionRadar processing that retains the received signal amplitude and phase but that removes the intermediate frequency carrier.
Synchronous GeneratorAn electrical generator that runs at a constant speed and draws its excitation from a power source external or independent of the load or transmission…
Synchronous InverterAn electrical inverter that inverts direct current electricity to alternating current electricity, and that uses another alternating current source, such…
Synchronous MotorA type of motor designed to operate precisely at the synchronous speed with no slip in the full-load speeds (rpm).
SynclineA fold in rocks in which the strata dip inward from both sides toward the axis. Troughlike downward sag or fold in rock layers. Opposite of an anticline.
SyncytiotrophoblastA multinucleated cell formed from the cells of the trophoblast. Only a small area of the syncytiotrophoblast is evident at the start of the formation of…
syncytiumA large cell-like structure formed by the joining together of two or more cells. The plural is syncytia.
syndrome(SIN-drome) A set of symptoms or conditions that occur together and suggest the presence of a certain disease or an increased chance of developing the…
synergidOne of the two haploid nuclei at the micropylar end of the embryo sac of higher plants. The third nucleus is the egg.
synergismAn interaction between two organisms (e.g. Rhizobium and legumes) in which the growth of one is helped by the other. Opposite: antagonism.
SyngasA syntheses gas produced through gasification of biomass. Syngas is similar to natural gas and can be cleaned and conditioned to form a feedstock for…
Syngeneic(SIN-juh-NAY-ik) Having to do with individuals or tissues that have identical genes.
synkaryonThe initial of the zygote, formed by the fusion of the gametic nuclei upon fertilization.
SYNOPSynoptic - relating to the general weather pattern over a wide region, such as areas of high and low pressure or frontal boundaries, as opposed to…
SynopsisA broad discussion of the weather pattern expected across any given area, generally confined to the 0-48 hour time frame.
Synoptic analysisSynoptic analysis The study of the synoptic observation data plotted on synoptic charts aimed at analysis of the atmospheric disturbances (for example…
Synoptic chartSynoptic chart A weather chart reflecting the state of the atmosphere over a large area at a given moment.
Synoptic CodeRules and procedures established by the World Meteorological Organization(WMO) for encoding weather observations.
Synoptic hourSynoptic hour Hour (UTC) determined by international agreement at which meteorological observations are made simultaneously throughout the world.
Synoptic meteorologySynoptic meteorology The study and analysis of synoptic weather information (synoptic charts, synoptic weather observations).
Synoptic ScaleThe spatial scale of the migratory high and low pressure systems of the lower troposphere, with wavelengths of 1000 to 2500 km.
Synoptic TrackWeather reconnaissance mission flown to provide vital meteorological information in data sparse ocean areas as a supplement to existing surface, radar…
Synoptic WeatherWeather occurring over a wide region on time scales exceeding 12 hours.
Synoptic weather observationSynoptic weather observation A surface weather observation, made at periodic times (usually at 3-hourly and 6-hourly intervals specified by the World…
Synthetic earthquakeEarthquake time history records developed from mathematical models that use white noise, filtered white noise, and stationary and nonstationary filtered…
Synthetic fertilizerCommercially prepared mixtures of plant nutrients such as nitrates, phosphates, and potassium applied to the soil to restore fertility and increase crop…
Synthetic natural gas (SNG)A manufactured product chemically similar in most respects to natural gas, resulting from the conversion or reforming of petroleum hydrocarbons.
syringylA component of lignin, normally only found in hardwood lignins. It has a six-carbon aromatic ring with two methoxyl groups attached.
SystemPhysically connected generation, transmission, and distribution facilities operated as an integrated unit under one central management, or operating…
System MixThe proportion of electricity distributed by a power provider that is generated from available sources such as coal, natural gas, petroleum, nuclear…