ENVIRSC 1C03 Lecture Notes - Lecture 8: Fluid Parcel, Unit, Sea Salt

• School: McMaster University
• Department: Environmental Science
• Course: ENVIRSC 1C03
• Professor: Luc Bernier

Document Summary

At earth"s surface, a parcel of air has the same temp and pressure as the air around it. So, a rising parcel of air expands and cools. A sinking parcel is compressed and warms. Adiabatic process: if a parcel of air expands and cools or compresses and warms with no interchange of heat with its surroundings. As long as the air in the parcel is unsaturated (relative humidity is < 100%), the rate of adiabatic cooling or warming remains constant. This rate of heating/cooling is ~10c for every 1000m of change in elevation and applies only to unsaturated air. For this reaso(cid:374), it"s (cid:272)alled the dry adiabatic lapse rate (dalr: called a (cid:862)lapse rate(cid:863) (cid:271)/(cid:272) te(cid:373)p de(cid:272)reases (cid:449)ith i(cid:374)(cid:272)reased ele(cid:448)atio(cid:374) Dry adiabatic lapse is not the same thing as the environmental lapse rate (elr) The elr does not involve the movement of an air parcel.