GEOL 102 Lecture Notes - Lecture 1: Lapse Rate, Natural Convection
Document Summary
Consider a hot parcel of air near the ground. The parcel will rise because a thermal is created. In order to determine a parcel will rise or sink in the atmosphere, we must compare the parcel temperature with that of the environmental temperature at the same altitude. As a parcel rises, it will adiabatically extend and cool. Adiabatic: a process where the parcel temperature changes due to an expansion of compression, no heat exchange with its environment. Due to low pressure outside allows the air molecules to push out on the parcel walls. So the tp changes upward further by moist lapse rate (6 c/km) It will rise on its own since tp>te. The height where tp=te is called the level of free convection (lfc) The parcel continues rising by moist lapse rate (6 c/km) until tp=te. Below lfc, atmosphere is stable due to tpte.
