Abstract:
Comparison of the lower trade-wind air under conditions of
strong versus weak circulation is continued, Moisture and thermal
structure and transports from the top of the mixed layer up to the
trade-wind inversion are investigated. Much less difference is
found at those levels between weak and strong circulation period
than was found in the lowest or mixed layer. It is shown that the
development of trade cumulus convection is dependent primarily upon
conditions below cloud while for immense cumulonimbus build-ups
convergence in the large-scale flow appears to be necessary.
A physical model of the moist layer is constructed which
describes the interaction of cloud populations with their surroundings,
It shows how the cloud groups, though they average
level-for-level both virtually and potentially colder than the
clear, are thermally direct circulations providing heat and
moisture to the trade. The model is built up from numerical
calculations based primarily upon the aircraft soundings made
in the undisturbed trade near Puerto Rico in April 1946 and
March - April, 1953.
