The Global Hydrologic Cycle:
Convective
Instability
We saw that clouds and rainfall can result from dynamic processes
(convergent winds).
But rainfall can also be caused
by thermodynamic processes if CAPE > 0.
What is CAPE?
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CAPE stands for Convective Available Potential Energy
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results from the buoyancy of parcels lifted from the boundary
layer (near the surface) through the free troposphere
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often causes deep convective motions in the tropics,
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can be approximated by the moist static
energy = Cp*T + lv*q
(Cp=1005 J kg-1
K-1 and lv=2.5 106 J kg-1)
Consider the following diagram illustrating the principle.....
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