The problem is many sided and we must consider the motion of

the air vertically as well as horizontally
The problem is many sided and we must consider the motion of
the air vertically as well as horizontally. Air gains and loses
heat chiefly by convection, and any gain or loss by conduction
may be neglected. The plant gains heat by convection, radiation
and perhaps by conduction of an internal rather than surface
character. The ground gains and loses heat chiefly by
radiation. But the whole process is complicated and may not
even be uniform. Frosts generally are preceded by a loss of
heat from the lower air strata, due to convection and a
horizontal translation of the air. Then follows an equally
rapid and great loss of heat by free radiation. There are minor
changes such as the setting free of heat in condensation and
the utilization in evaporation, but these latent heats are of
less importance than the actual transference of the air and
vapor and the removal of the latter as an absorber and retainer
of heat.