Ordinary-cell convective storms - Severe Convective Storms and Tornadoes: Observations and Dynamics - page 92

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Ordinary-cell convective storms
''I am the daughter of Earth and Water
And the nursling of the Sky;
I pass through the pores of the ocean and shores
I change, but I cannot die.
For after the rain with never a strain
The pavilion of Heaven is Gale,
And the winds and sunbeams with their convex gleams
Build up the blue dome of air,
While I gently laugh at my own cenotaph,
And out of the caverns of rain,
Like a child from the womb, like a ghost from the tomb
I arise and unbuild again.''
Percy Bysshe Shelley—The Cloud
In the previous chapter, we considered the dynamics of (mostly) dry convection
and found that buoyancy and dynamic pressure gradient forces are of funda-
mental importance. In addition, vertical shear was shown to be able to organize
shallow convection into lines under some circumstances. We considered the
inclusion of water substance only in how it affects buoyancy (i.e., adding or
increasing liquid water reduces buoyancy and adding or increasing water vapor
reduces buoyancy). We will now consider the effects of water substance on convec-
tion more completely. We refer to ''moist convection'' as small-scale convective
currents consisting of air parcels that contain water substance in potentially all of
its phases.
The dynamics of moist convection is even more complicated than the already
complicated dynamics of dry convection. Not only must we be concerned with
buoyancy, the turbulent entrainment of environmental air, and the effects of