Figure 1-3.—Frontal lift-stable air causing stratiform cloud development along a warm front.
Figure 1-4.—Turbulent lift.
caused by the spinning of the earth and the path of each
molecule through the atmosphere. Although the theory
is complex, the net result is that air following a
cyclonically curved path through the atmosphere tends
to rise, while air following an anticyclonically curved
path tends to subside. Vorticity is the leading cause of
most middle- and high-level, nonfrontal cloudiness.
Air may become saturated without being lifted. At
night, air may cool by radiation of heat in a process
known as radiational cooling. Warm, moist air may
move over a cooler surface, such as a cool body of land,
and cool to saturation by conduction. Conduction is the
transfer of heat energy through contact. Finally, air may
also be brought to saturation by the addition of moisture
Figure 1-5.—Convective lift.
1-5
