- 行业: Earth science
- Number of terms: 10770
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The UK charity dedicated to the protection of the marine environment and its wildlife.
Waves that propagate under the influence of buoyancy forces. Gravity waves include surface gravity waves, such as waves on the surface of the ocean, interfacial gravity waves, such as waves at the interface between fresh surface water and underlying salty ocean water, and internal gravity waves which propagate vertically as well as horizontally in density stratified fluid.
Industry:Earth science
Within a channel in a rotating system, a Poincare' wave has sinusoidally varying cross-channel velocity with an integral or half integral number of cross-channel waves spanning the channel. In the shallow water approximation the waves have dispersion relationship with squared frequency \omega^2 = f^2 + c^2 (k^2 + n^2 \pi^2/L^2), in which f is the Coriolis parameter, k is the along channel wavenumber, L is the width of the channel, n is any positive integer, and c is the phase speed for shallow water gravity waves: c=(gH)^(1/2), in which g is the acceleration due to gravity and H is the mean depth of the fluid. Related to Poincare' waves are Kelvin waves which take the role of the mode with n=0.
Industry:Earth science
Energia del calore che può essere sentita o misurata direttamente con un termometro.
Industry:Earth science
Momento del periodo di marea in cui essa defluisce. Vedere "flood tide".
Industry:Earth science
L'effetto serra fa sì che l'atmosfera trattenga una maggiore quantità di energia sotto forma di calore a livello della superficie terrestre e nell'ambito dell'atmosfera assorbendo e riemettendo energia a onda lunga. Di tutta l'energia a onda lunga riemessa nello spazio, il 90% viene captato e assorbito dai gas a effetto serra. Senza l'effetto serra la temperatura globale terrestre media sarebbe di -18° Celsius invece degli attuali 15° Celsius. Nei secoli scorsi le attività umane hanno direttamente o indirettamente provocato un aumento della concentrazione dei principali gas a effetto serra. Gli scienziati prevedono che questo aumento possa accentuare l'effetto serra e rendere più caldo il pianeta. Alcuni esperti sostengono che la temperatura globale media della terra sia già aumentata tra 0,3 e 0,6 gradi centigradi dall'inizio del secolo a causa di questo incremento.
Industry:Earth science
A hypothetical, ideal radiator that totally absorbs and reemits all energy incident upon it. Actual objects only approach this ideal.
Industry:Earth science
An instability of an unbounded parallel shear flow to the growth and nonlinear development of waves with phase speed in the along flow direction approximately equal to the speed of the inflection point of the shear. This is also referred to as shear instability and is a specific example of barotropic instability. The instability, whether in homogeneous or stratified fluid, occurs due to a resonant coupling between wave-like disturbances on either flank of the shear flow where the gradient of the shear is non-zero. Increasing stratification acts to inhibit the growth of the instability.
Industry:Earth science
1. Developed by Gustav Mie in 1908, this is a complete mathematical-physical theory of the scattering of electromagnetic radiation by spherical particles. In contrast to Rayleigh scattering, the Mie theory embraces all possible ratios of diameter to wavelength. See size parameter. The Mie theory is very important in meteorological optics, where diameter-wavelength ratios of the order of unity and larger are characteristic of many problems regarding haze and cloud scattering. Scattering of radar energy by raindrops constitutes another significant application of the Mie theory. Compare to Rayleigh Scattering.
2. Processes by which particles of similar size and electrical characteristics separate or disperse different wavelengths (colors) of light. Since the Sun's visible spectrum contains a mixture of red, orange, yellow, green, blue, indigo, and violet colors, these wavelengths are differentially scattered by particles as they travel through the atmosphere.
Industry:Earth science
A remote sensing instrument capable of identifying sub-surface archaeological features by measuring the difference in their magnetic properties against the surrounding soils.
Industry:Earth science
Corrente oceanica stagionale che scorre lungo la costa occidentale dell'Australia. Durante l'estate dell'emisfero meridionale essa scorre verso nord, poi piega verso ovest per congiungersi con la corrente sudequatoriale. Durante l'inverno dell'emisfero meridionale la corrente occidentale australiana scorre in direzione sud.
Industry:Earth science
