Response
Gorshkov V.G., Makarieva A.M. (2006): Response to the
question on condensation, heat release and evaporative force.
www.biotic-regulation.pl.ru/pump/comm7.htm
This question, although simple, is quite fundamental in its physics.
Importantly, condensation CANNOT LEAD TO HEATING (i.e. rise of temperature). Condensation can only partially counteract and weaken THE DROP OF TEMPERATURE that initiated condensation.
Imagine that you have a jar with saturated water vapor. How can you
condense it? By DECREASING temperature of the jar. Then, during condensation,
some heat will be released. But the jar temperature will not rise, it will DROP LESS than
it would without condensation. That is why moist adiabatic lapse rate is less
than dry adiabatic lapse rate.
Now let us think again from a different angle. Imagine one takes some heat
away from that saturated jar, temperature drops, water vapor
condenses, heat is released and warms the jar to a temperature higher
than the initial one. What will happen? Water vapor will evaporate again,
because the temperature has risen. So ultimately you will see no
condensation at all. This means that if one does observe
condensation, the temperature can do nothing but drop.
But this is not very relevant to the picture of the evaporative
force. Here everything is clear. Temperature of the rising air
parcels drops, water condenses and produces pressure shortage.
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