- 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, ...
Any type of variation in the appearance or energy output of the sun; usually associated with the variation of sunspots and other features over the 11-year solar cycle. The number and magnitude of these features vary with time, from minimum values to maximum values, that is, from solar minimum to solar maximum. See faculae, flare, granules, plage, prominence, spicules, sunspot.
Industry:Weather
Any stationary cloud maintaining its position with respect to a mountain peak or ridge, such as a banner cloud, cap cloud, crest cloud, or cloud of the species lenticularis.
Industry:Weather
Any process (chemical or physical) that removes a particular chemical species from the atmosphere. The abundance of a species in the atmosphere can be determined from a consideration of the various sources of the compound to the atmosphere and the sink processes that remove it.
Industry:Weather
Any piece, body, or area of ice that is in the process of melting or disintegrating. It is characterized by honeycomb structure, weak bonding between crystals, or the presence of meltwater or seawater between grains. Rotten ice may appear transparent (and thus dark) when saturated with seawater and so may be easily confused with newly forming black ice.
Industry:Weather
Any physical quantity with a field that can be described by a single numerical value at each point in space. A scalar quantity is distinguished from a vector quantity by the fact that a scalar quantity possesses only magnitude, whereas a vector quantity possesses both magnitude and direction. Thus, pressure is a scalar quantity and velocity is a vector quantity.
Industry:Weather
Any parameter of a system, for example, velocity components or temperature, that may or may not have been assumed to be small perturbations from a mean or steady- state value.
Industry:Weather
Any one of a family of large, colored, circular (or nearly circular) arcs formed by light (usually sunlight) falling on a population of water drops such as provided by rain, cloud, fog, or spray. The apparent center of the arcs is normally the shadow of the observer's head, so the rainbow is a personal phenomenon with each person seeing a slightly different bow. Although the rainbow can form a circle, when caused by rain the bottom part of the circle is usually cut off by the ground, leaving an arc, the extent of which depends upon the elevation of the light. The term rainbow is not applied to the small, nearly circular arcs seen around the sun and antisolar point in clouds. These are the corona and glory. Nor is the term applied to the large circular arcs formed by light falling on ice crystals. These are the halos. Rainbows are seen as related groups of arcs, such as the primary rainbow (with red on the outside, blue on the inside), the (larger) secondary rainbow (with red on the inside), the supernumerary rainbows (seen to the inside of the primary bow), and the reflection bows (the centers of which are above the horizon). However, the appearance of these bows can vary markedly depending upon whether they formed in rain, drizzle, or cloud, as both the radius and color purity of the arcs depend on drop size. Certainly, the brightest and most frequently seen of the bows is the primary rainbow, but whether the whole arc above the horizon is seen or not depends upon the location of the rain. It is not uncommon for someone to report seeing two rainbows, when these were merely two unconnected portions of the same bow. There is a hierarchy of theories of the rainbow with simplicity being purchased at the expense of verisimilitude. Theories that treat light as a series of rays do a good job of explaining the approximate positions and colors of the primary and secondary bows but fail to account for the supernumerary bows. To account for such easily observable features of the natural bow as the variations of color purity, brightness, and distribution of the supernumeraries around the arc, such things as the wave nature of light, the drop-size distribution in a cloud, and the size- dependent shape of raindrops must be taken into account.
Industry:Weather
