GEOS 220 Lecture Notes - Lecture 7: Buoyancy, Atmospheric Instability, Radiative Cooling
Document Summary
Air after being lifted or lowered returns to its original position. Parcel of air: unit of air with an avg. At the dew-point, air cools at the moist adiabatic rate, which is not constant. Determined by comparing the temp. of rising air to surroundings. Stable air: rising air is colder than the environment, it will be most dense and sink back to original level. Unstable air: rising air is warmer than environment= less dense than surrounding air, it will conitue to rise until it reaches the same temperature as the environment. Environmental lapse rate of decrease in air temp. with elevation the atmosphere is absolutely stable when the environmental lapse rate is less than the moist adiabatic rate. Small environmental lapse rate- air a loft warms or surface air cools. Surface air cooling may be due to: An influx of cold surface air brought by winds. Air moving over a cold surface the atmosphere is the most stable.
