MOVEMENTS OF ATMOSPHERE GULDBERG AND MOHN l6l 



we shall have 



tang ^ta^« 



X- 2c 

 k 



Equations (i) and (2) may be written 



c 

 v = .r (7) 



cos /? 

 tG = &- c)c r (8) 



p COS 2 /? 



Attributing to p a mean value, we can write 



G = G t r (9) 



in which G x denotes a constant magnitude and r is expressed in 

 degrees of the meridian. 

 Then we have 



b - b = 1/2 G t r 2 (10) 



in which b is the pressure in millimeters at the center. Thus the 

 curve of pressure becomes a parabola. 



The preceding formulas apply to whirls around a barometric 

 minimum; by making c negative and substituting (180 + /?) for 

 /? we shall have the following formulae which apply to a whirl about 

 a barometric maximum: 



tang /? = ^ (11) 



e c „(A±fL'. r (12) 



p COS 2 ft 



Applications 



(1) Whirlwind of great velocity about a barometric minimum (see 

 fig- 9)- 



Consider the central part of the whirlwind No. 1 in §12. 

 Let 



/? = S9° 45';^ =0.00103; (r =20°, b = 735 mm ) 

 9 



