The Dry adiabatic lapse rate reference article from the English Wikipedia on 24-Apr-2004 (provided by Fixed Reference: snapshots of Wikipedia from wikipedia.org)
The dry adiabatic lapse rate is the rate at which the temperature of a parcel of dry air decreases as the parcel is lifted in the atmosphere. The dry adiabatic lapse rate (abbreviated DALR) is 5.5ÃÂðF per 1000 ft or 9.8ÃÂðC per km.