98 
THERMODYNAMIC METEOROLOGY 
strata so generally seen in the atmosphere. This confirms the 
principle of equations (36) to (38), which indicate the relations 
of pressure, circulation, and radiation to gravitation. 
It is easy to see that such data are capable of making all the 
general thermodynamic formulas (205) to (328), and many others, 
applicable to the earth’s non-adiabatic atmosphere. It should 
be carefully noted that the density p, and the gas coefficient R, 
must be computed by (176), (177), and not by (175) for R a con 
stant; that the effective specific heat Cp is variable, and that 
radiation depends upon this fact. The principal quantities to 
obtain by observation are the temperature T, and the velocity 
of circulation q at the height z, and hence the observations for 
temperature alone, omitting q, are not capable of giving correct 
radiation data. Finally, the variation of pressure — dP is not 
proportional to the mass gpdz=gdm, but by (201) the terms 
p qd q + p dQ must be added for circulation and radiation, or 
else P — — K, which is to exclude them from the problem, and 
reduce it to the unusual adiabatic case. One can now perceive 
that there is no possibility of solving the general equations of 
motion in cyclones and anti-cyclones, and in all the other types 
of circulation, without first eliminating the heat term d Q. Nearly 
all attempts of meteorologists to solve the circulation problems 
have been futile chiefly on this account, because of the assumed 
necessity of ascribing to friction, and to the deflecting force of 
the earth’s rotation on a moving mass, values which they do not 
actually possess. We shall be able to explain this more fully 
in the chapter on Dynamic Meteorology, but now proceed to 
illustrate more at length the thermodynamic terms in other 
typical conditions of the atmosphere. 
The Diurnal Convection and the Semi-diurnal Waves in the Lower 
Strata 
There is a series of problems relating to the semi-diurnal 
waves observed at the surface, which have been much discussed 
without satisfactory results, as the semi-diurnal barometric 
waves and the several electrical and magnetic waves which are