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.
Unstable modes have height, vorticity, vertical velocity, and several other atmospheric parameters with contours that tilt westward with height, though temperature contours tilt eastward with height for unstable modes. A poleward heat flux is observed in unstable modes, yielding the positive feedback necessary for cyclogenesis. Low pressure ...
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 ...
The atmosphere is warm at the surface and lower levels of the troposphere where there is mixing (the planetary boundary layer (PBL)), but becomes substantially cooler with height. The temperature profile of the atmosphere, the change in temperature, the degree that it cools with height, is the lapse rate.
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 ( mb ).
Heat forces air to rise and makes the atmosphere unstable. The atmosphere then creates clouds, storms and wind to let out heat energy in an attempt to bring itself back into balance.
If enough instability is present in the atmosphere, this process will continue long enough for cumulonimbus clouds to form, which supports lightning and thunder. Generally, thunderstorms require three conditions to form: moisture, an unstable airmass, and a lifting force (heat).
Saturday’s ring of fire annular solar eclipse will alter weather conditions on the Earth’s surface as it plays out in the sky.