GEOG 2110L Chapter Notes -Fluid Parcel, Dew Point
Document Summary
** warm air is less dense(lighter) and thus rises. * as air rises in the atmosphere, it expands. * a parcel (or "bubble") of air comes under less & less pressure as it rises & thus expands. * as a gas (air) expands, the molecular action (kinetic energy) decreases thus the t decreases. ** cold air is more dense (heavier) and thus sinks. * as air sinks in the atmosphere, it compresses. * a parcel of air comes under more & more pressure as it sinks & thus is compressed. * as a gas (air) compresses, the molecular action (kinetic energy) increases thus the t increases. ** but, the t changes without heat being added or subtracted. *** this is adiabatic temperature change: changing the t of the air without adding or subtracting heat. Simply the result of compressing the sir or allowing it to expand. Result: ** rising air in the atmosphere expands & cools.