- Industry: 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 front that is stationary or nearly so. Conventionally, a front that is moving at a speed less than about five knots is generally considered to be quasi-stationary. In synoptic chart analysis, a quasi-stationary front is one that has not moved appreciably from its position on the last previous synoptic chart (three or six hours before).
Industry:Weather
A method of winds-aloft observation, that is, the determination of wind speeds and directions in the atmosphere above a station. This is done by reading the elevation and azimuth angles of a theodolite while visually tracking a pilot balloon. The ascension rate of the balloon is approximately determined by careful inflation to a given total lift. After release from the ground, periodic readings (usually at one-minute intervals) of elevation and azimuth angles of the balloon are recorded. These data are transferred to a winds- aloft plotting board, and the wind speed and direction at selected levels are calculated by trigonometric methods. See graphing board, winds-aloft plotting board; Compare rabal, rawin, rawinsonde, double-theodolite observation.
Industry:Weather
Sound-wave transmitting and receiving equipment operated on principles analogous to those of radar. Irregularities in atmospheric temperature and wind velocity constitute sources of scattering for acoustic waves. Sodars measure vertical profiles of the mean and turbulent properties of the sound to heights of several hundred meters by transmitting acoustic waves upward and measuring the Doppler shift in the backscattered acoustic signals. Sodar is sometimes inappropriately called acoustic radar.
Industry:Weather
A report of in-flight weather by an aircraft pilot or crew member. A complete report includes the following information in this order: location and/or extent of reported weather phenomena; time of observation; description of phenomena; altitude of phenomena; type of aircraft (only with reports of turbulence or icing). This term is also applied to more informal and less complete reports of weather aloft as well as to post-flight reports filed after landing. Compare aircraft observation.
Industry:Weather
A report of in-flight weather by an aircraft pilot or crew member. A complete report includes the following information in this order: location and/or extent of reported weather phenomena; time of observation; description of phenomena; altitude of phenomena; type of aircraft (only with reports of turbulence or icing). This term is also applied to more informal and less complete reports of weather aloft as well as to post-flight reports filed after landing. Compare aircraft observation.
Industry:Weather
