"Darrell S" wrote in message
news:bdUNd.46622$bu.24635@fed1read06...
2°/1000' is "average" since air at different levels may be saturated
or unsaturated and can change from one to the other
at different levels. Lifted air would cool at 3°/1000' while
lifting through dry air and at 1°/1000' lifting through moist air levels.
So.... the average is 1°


no, No, NO!!!

The 2 degrees per 1000 feet comes from a "determined" average lapse rate of
real atmospheres averaged around the globe and averaged throughout time....
determined within reason. It has nothing, NOTHING, to do with saturated or
unsaturated or dry adiabatic or saturated adiabatic. Dry and Saturated
adiabatic lapse rates are a law-of-physics-rates-of-cooling, not actual
temperatures in the real nor in the "standard" atmosphere.

Please divorce those two concepts:

First concept:
Environmental lapse rate: temperature structure of the real atmosphere
right now. Usually, but not necessarily, cools with height. How much per
1000 feet? Depends on the structure TODAY, THIS INSTANT. Not constant
throughout. May be several degrees per 1000 feet in some layers, zero in
others, and even an inversion in still others.

.... and Standard Atmosphere Lapse Rate: defined at "lowering 1.98 degrees
per 1000 feet" within the troposphere (lowest 11 kilometres).

Second concept:
Dry Adiabatic lapse rate: a RATE-OF-COOLING (or heating) of a parcel of air
should it be displaced from its present level and rise (or descend) through
the atmosphere, with the consequent pressure change on it. The
"dry-adiabatic" rate of cooling will occur as long as no moisture is being
condensed. About 3 degrees per 1000 feet, reasonably linear with height.

.... and Saturated Adiabatic lapse rate: a RATE-OF-COOLING (or heating) of a
parcel of air should it be displaced from its present level and rise (or
descend) through the atmosphere, with the consequent pressure change on it.
The "wet-adiabatic" rate of cooling (or heating) will occur as long as the
relative humidity of the parcel is 100 percent and moisture is being
condensed (or evaporated if descending). This rate is less than the
dry-adiabatic rate, because the condensation of moisture releases heat which
slows the cooling of the air. Not linear with height. Varies from about 1
degrees per 1000 feet at very high dewpoints, to almost 3 degrees per 1000
feet at very low dewpoints.

Two different concepts!