- 行业: Weather
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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, ...
A device for measuring soil water amounts, especially under roads; seldom used.
Industry:Weather
1. A swinging, as of a pendulum. Often applied to periodic motion or variation in time of any quantity, although may mean any more or less regular variation between fixed bounds. Fluctuation is more suggestive of irregular variation. Vibration is a near synonym except that oscillation is applied to variations in space as well as time. The amplitude of a damped oscillation steadily decreases. Oscillations are said to be forced or free according to whether the oscillating system is or is not acted upon by an external force, although what constitutes such a force is a matter of convention. An ordinary pendulum is acted on by the external force of gravity, and yet the pendulum probably would be described as undergoing free oscillation. 2. As used by Sir Gilbert Walker, a single number, empirically derived, that represents the distribution of pressure and temperature over a wide ocean area. Basically, the process is one of weighting pressure and temperature values for selected island and coastal stations, and algebraically combining them. These numbers were originally employed in correlations with single station values. Three such “oscillations” were derived: the North Atlantic oscillation; the North Pacific oscillation; and the Southern Oscillation.
Industry:Weather
The path that a satellite follows in its motion through space relative to the attracting body.
Industry:Weather
A particular circular path beginning at the satellite's ascending node. The orbit number from launch to the first ascending node is designated as zero.
Industry:Weather
A collection of quantities that, together, describe the size, shape, and orientation of an orbit. The classical orbital elements include the semimajor axis, eccentricity, inclination, argument of perigee, right ascension of ascending node, mean anomaly, and epoch time.
Industry:Weather
In hydrodynamics, the motion of a fluid particle induced by the passage of a progressive gravity wave. When the wave height is small and the fluid depth is great, the orbit is a circle the radius of which decreases exponentially with depth. In shallow fluids, the orbit is an ellipse, which degenerates into a horizontal line at the bottom boundary of the fluid.
Industry:Weather
As an ocean wave propagates, the water itself moves in an approximately circular motion (in deep water), with the amplitude of the motion decaying with depth below the sea surface. The velocity associated with the fluid motion is known as the orbital (or particle) velocity.
Industry:Weather
The most basic component of a convective storm, consisting of a single main updraft that is usually quickly replaced by a downdraft once precipitation begins. Ordinary cells are especially observed in environments with weak vertical wind shear, and typically have lifetimes of 30–50 minutes. Ordinary cells are the primary component of multicell storms. See also convective cell, multicell convective storm, thunderstorm.
Industry:Weather
