- 行业: Weather
- Number of terms: 60695
- Number of blossaries: 0
- Company Profile:
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, ...
Water brought to the earth's surface from great depths by the upward movement of intrusive igneous rocks. The quantities of neither magmatic water nor connate water are appreciable in comparison to meteoric water.
Industry:Weather
At any point on the earth's surface, the horizontal direction of the earth's magnetic lines of force (direction of a magnetic meridian) toward the north magnetic pole, that is, a direction indicated by the needle of a magnetic compass. Because of the wide use of the magnetic compass, magnetic north, rather than true north, is the common 0° (or 360°) reference in much of navigational practice, including the designation of airport runway alignment.
Industry:Weather
The magnitude of the magnetic field at any point. Strictly speaking, the magnetic field is the set of all values of the magnetic field intensity, but magnetic field and magnetic field intensity (as well as magnetic field strength and magnetic vector) are used more or less interchangeably. The trend is to use magnetic field both for the field taken as a whole and for its value at any point, context being sufficient to determine precise meaning.
Industry:Weather
Double refraction (or linear birefringence) induced in a medium as a consequence of a magnetic field applied to it; discovered in 1902 by Voigt, who showed that light propagating in a vapor to which a strong, perpendicular magnetic field is applied exhibits double refraction. The Cotton–Mouton effect (discovered in 1907) is the Voigt effect in a liquid. All double refraction results from anisotropy. Magnetic fields applied to otherwise isotropic media provide the anisotropy necessary for magnetic double refraction. Radio waves propagating in the ionosphere may exhibit magnetic double refraction as a consequence of the geomagnetic field.
Industry:Weather
Water brought to the earth's surface from great depths by the upward movement of intrusive igneous rocks. The quantities of neither magmatic water nor connate water are appreciable in comparison to meteoric water.
Industry:Weather
1. In geomagnetism, either of the two points on the earth's surface where a free- swinging magnetic needle points in a vertical direction. The line connecting these two points does not pass through the center of the earth. These two points constantly move at a slow rate. They are presently in northern Canada and in the Antarctic south of Australia. 2. See dipole.
Industry:Weather
A northwesterly wind with fine weather that blows, especially in summer, in the Adriatic; it is most frequent on the western shore and is equivalent to the etesians of the eastern Mediterranean. It is also found on the coasts of Corsica and Sardinia. Compare mistral.
Industry:Weather
A tidal whirlpool found between the islands of Moskenesy and Mosken in the Lofoten Islands of northern Norway. The term is generally applied to other tidal whirlpools.
Industry:Weather
A quantity with the dimensions of kinematic viscosity, defined as ''u''<sub>*</sub>''z''<sub>0</sub>, where ''''u''<sub>*</sub> is the friction velocity and ''z''<sub>0</sub> the aerodynamic roughness length. In smooth flow the macroviscosity is of the order of one-tenth the kinematic viscosity. In normal atmospheric flow, which is fully rough, it is of the order of 10<sup>−2</sup> m<sup>2</sup>s<sup>−1</sup>, or about 1000 times the kinematic viscosity. See logarithmic velocity profile.
Industry:Weather
