Search results
Results from the WOW.Com Content Network
Atmospheric instability is a condition where the Earth's atmosphere is considered to be unstable and as a result local weather is highly variable through distance and time. [ clarification needed ] [ 1 ] Atmospheric instability encourages vertical motion, which is directly correlated to different types of weather systems and their severity.
Any atmospheric circulation system, whether it is a small-scale weather system or a large-scale zonal wind system, is maintained by the supply of kinetic energy.The development of such a system requires either a transformation of some other form of energy into kinetic energy, or the conversion of the kinetic energy of another system into that of the developing system. [3]
Stable stratification of fluids occurs when each layer is less dense than the one below it. Unstable stratification is when each layer is denser than the one below it. Buoyancy forces tend to preserve stable stratification; the higher layers float on the lower ones. In unstable stratification, on the other hand, buoyancy forces cause convection ...
If the acceleration is back towards the initial position, the stratification is said to be stable and the parcel oscillates vertically. In this case, N 2 > 0 and the angular frequency of oscillation is given N. If the acceleration is away from the initial position (N 2 < 0), the stratification is unstable. In this case, overturning or ...
Classes range from 1 (most unstable) to 7 (most stable). The Turner stability class system was devised by D. B. Turner as a modification of the Pasquill stability class system. [1] The following table is used to determine the Turner stability class for a given wind speed and net solar radiation:
A stable atmosphere makes vertical movement difficult, and small vertical disturbances dampen out and disappear. In an unstable atmosphere, vertical air movements (such as in orographic lifting , where an air mass is displaced upwards as it is blown by wind up the rising slope of a mountain range) tend to become larger, resulting in turbulent ...
By contrast, other conditions, such as a less warm air parcel or a parcel in an atmosphere with a temperature inversion (in which the temperature increases above a certain height) have much less capacity to support vigorous upward air movement, thus the potential energy level (CAPE) would be much lower, as would the probability of thunderstorms.
Unstable areas are in yellow (slightly) and red (highly) while the stable zone is in blue. The lifted index (LI) is the temperature difference between the environment Te(p) and an air parcel lifted adiabatically Tp(p) at a given pressure height in the troposphere (lowest layer where most weather occurs) of the atmosphere, usually 500 hPa . The ...