- 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, ...
A hygrometer that uses a transducing element with electrical properties that are a function of atmospheric water vapor content. Examples of such a transducer are the humidity strip, the carbon-film hygrometer element, thin-film capacitors, aluminium oxide humidity elements, and goldbeater's skin hygrometers.
Industry:Weather
A record obtained in a well, by means of a traveling electrode, that gives a detailed picture of the characteristics and thickness of the various geologic strata, and an indication of the water quality, by measuring the apparent resistivity of the materials surrounding the well bore.
Industry:Weather
The sudden decrease of resistivity of a substance when the applied electric field strength rises above a certain threshold value (the substance's dielectric strength). For air at normal pressures and temperatures, experiment has shown that the breakdown process occurs at a field strength of about 3 × 106 V m−1. This value decreases approximately linearly with pressure, and is dependent upon humidity and traces of foreign gases. In the region of high field strength just ahead of an actively growing leader in a lightning stroke, breakdown occurs in the form of a rapidly moving wave of sudden ionization (electron avalanche). The dielectric strength in a cloud of water drops is less than that in cloud-free humid air.
Industry:Weather
Measure of the ability of material to conduct an electrical current. For water samples, it depends on the concentration and type of ionic constituents in the water and the temperature of the water; it is expressed in millisiemens per meter, or micromhos per centimeter.
Industry:Weather
The electrical force exerted on a unit positive charge placed at a given point in space. The electric field strength is expressed, in the mks system of electrical units, in terms of volts per meter and is a vector quantity. The electric field strength of the atmosphere is commonly referred to as the atmospheric electric field.
Industry:Weather
Imaginary curves in space tangent to the electric field at each point; analogous to streamlines in fluid mechanics.
Industry:Weather
A stream with a flow maintained by base flow during long rainless periods.
Industry:Weather
The magnitude of the electric field at any point. Strictly speaking, the electric field is the set of all values of the electric field strength, but electric field and electric field intensity (as well as electric field strength and electric vector) are used more or less interchangeably. The trend is to use electric 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
1. A vector field, usually denoted by E, defined as follows: at a given time and at each point in space the force experienced by a positive charge (sometimes called a test charge) at that point divided by the magnitude of the charge, taken to be sufficiently small that it does not affect the positions and velocities of all other charges. The set of all vectors thus obtained is the electric field, although this term is often used for its value at any given point. The magnitude of the vector is the electric field intensity and the direction of the vector is parallel to the lines of force. 2. Same as electric field strength. See atmospheric electric field.
Industry:Weather
An interfacial region, near the boundary between two different phases of a substance, in which physical properties vary markedly (in contrast with those in the bulk phases). For electrically conducting phases, charge distribution occurs in this interfacial region, which may be approximated as two parallel sheets of charge of opposite sign, hence the term double layer. This name is retained even if the interfacial region is more complex. Double layers arise from an excess of charge, which may be electrons, ions, or oriented dipoles, in the interfacial region.
Industry:Weather
