1.3 Thermodynamic Requirements for Formation
The formation of TCs whose circulation extends through most of
the troposphere is the most difficult task that the tropical
atmosphere performs. It is seldom accomplished. The crucial
problem in understanding the cyclone formation processes is that of
understanding how the 500-200 hPa levels can increase their
enthalpy (thermodynamic energy). It appears that this can only be
accomplished in areas of weak vertical wind shear. These are areas
where the upper tropospheric environmental winds, and the
disturbance from which the cyclone forms, move with very much the
same direction and speed (Gray, 1975).
Section 1.2
Section 1.4
Chapter 3