- 行业: Weather
- Number of terms: 60695
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The American Meteorological Society promotes the development and dissemination of information and education on the atmospheric and related oceanic and hydrologic sciences and the advancement of their professional applications. Founded in 1919, AMS has a membership of more than 14,000 professionals, ...
The ratio of the vapor pressure to the saturation vapor pressure with respect to water. This quantity is alternatively defined by the World Meteorological Organization as the ratio of the mixing ratio to the saturation mixing ratio. These two definitions yield almost identical numerical values. Relative humidity is usually expressed in percent and can be computed from psychrometric data. Unless specified otherwise, relative humidity is reported with respect to water rather than ice because most hygrometers are sensitive to relative humidity with respect to water even at subfreezing temperatures, and because the air can easily become supersaturated with respect to ice, which would require three digits in coded messages for relative humidity with respect to ice.
Industry:Weather
The ratio of the size of a spherical scattering particle to the wavelength of the radiation being scattered, that is, α = π''d''/λ, where ''d'' is the diameter of the particle, and λ is the wavelength of the incident radiation. Mie theory describes the general process of extinction, scattering, and absorption of spherical particles as a function of the size parameter and refractive index. For α < ≈0. 1, the Rayleigh scattering approximation becomes valid, whereas for α > ≈100, geometrical optics becomes valid.
Industry:Weather
The ratio of the vapor pressure to the saturation vapor pressure with respect to ice.
Industry:Weather
The ratio of the scattering coefficient to the extinction coefficient. The single-scatter albedo affects radiative transfer in a scattering medium and is typically a function of wavelength. Throughout much of the visible spectrum, the single-scatter albedo of clouds and most atmospheric gases is very close to unity, and it typically varies considerably throughout the infrared spectrum.
Industry:Weather
The ratio of the scattering cross section to the geometrical cross section. Scattering efficiency factors increase with the sixth power of the radius for Rayleigh scatterers and tend to a value of 2 for nonabsorbing scatterers in the geometric optics limit.
Industry:Weather
The ratio of discharge into a recharge well to the rise of head at equilibrium.
Industry:Weather
The ratio of reflected-to-incident shortwave flux density at the top of the atmosphere. Planetary albedos are a function of time and space, depending in particular on the nature of cloud and ground cover. For the earth as a whole, the long term average planetary albedo is about 0. 31.
Industry:Weather
The ratio of the output signal power to the input signal power of a receiver, usually expressed in decibels.
Industry:Weather
The ratio of the density of a substance to the density of water, usually determined at 4°C.
Industry:Weather
The ratio of the amount of evaporation from a large body of water to that measured in an evaporation pan.
Industry:Weather
