104 
THERMODYNAMIC METEOROLOGY 
TABLE 25 
The Corresponding Values of B c =P/g 0 p m on the Level z = 000 
Meters Are Now Given, and Compared with the Observed Values 
of B 0 by Means of the Differences 
Surface 
2 A.M. 
6 A.M. 
10 A.M. 
2 p.m. 
6 P.M. 
10 p.m. 
Mean 
Be 
760.20 
760.88 
761.03 
759.18 
758.70 
760.70 
760.12 
Bo 
760.16 
760.75 
760.98 
759.52 
758.71 
760.59 
760.12 
&B C 
+0.08 
+0.76 
+0.91 
-0.94 
-1.42 
+0.58 
A Bo 
+0.04 
+0.63 
+0.86 
-0.60 
-1.41 
+0.47 
These curves can be reduced to the harmonics if desired. The 
value of the radiation exponent is a = 3.82 throughout the 
twenty-four hours. 
The Thermodynamic Structure of Cyclones and Anticyclones 
There has been much speculation regarding the forces that 
generate the powerful circulations in storms known by the name 
of cyclones and anticyclones, or low-pressure and high-pressure 
areas respectively. These will be more fully mentioned in the 
chapter on Dynamic Meteorology, but here we proceed to apply 
the principles just illustrated in the diurnal convection. From 
numerous kite and balloon ascensions in all parts of these local 
circulations, it has been learned what is the usual distribution 
of the temperature, and from the cloud observations what is the 
direction and velocity of the wind motion or “vector” in all 
areas, and all altitudes up to at least 10,000 meters. Compare 
the International Cloud Report, 1898, the Monthly Weather 
Review, January to July, 1902, April to June, 1904, January to 
August, 1906, October, 1907, to February, 1909, also the daily 
Weather Synoptic Charts, for numerous studies and details. 
From these data we have selected the temperatures T, and veloc 
ities q, given in Tables 26, 25, and Figs. 11, 12. The computed 
values of the pressure P, and the free heat (Qi — Q 0 ) are given 
in the same tables and figures, while the other thermodynamic 
data are summarized in Bulletin No. 3, O. M. A. Only three 
diagrams are extracted from the tables, but these are enough to