|
Definition:
|
Commonly, and in aviation terminology, the lowest altitude in the atmosphere, over a given location, at which the air temperature is 0C; the height of the 0C constant-temperature surface. This simple concept may become slightly complicated by the existence of one or more "above- freezing layers" formed by temperature inversions at altitudes higher than the above-defined freezing level. In cloud physics terminology, this is more accurately termed the melting level, for melting of ice always occurs very near 0C, but liquid cloud drops may remain supercooled to much colder temperatures.
|