PAPER BY PROF. OBERBECK. 



167 



Til. NUMERICAL EXAMPLE FOR A CYCLONE: NOTE ON ANTICY^CLONES. 



In order to show the applicability of the formuLne obtained in the last 

 section to cyclones as they actually occur in nature, I have executed 

 the following computation of a numerical example: 



In this computation I have assumed 



A = 0.00012 



This value corresponds to an average latitude of 55.5°. For Jc I have 

 assnmed the same value, whereby the value obtained for the influence 

 of friction is rather large. 



For the complete determination of the system of winds the constant 

 c of the ascending current of air and the dimensions of the inner region 

 must also be known. We can obtain this in various ways. We can 

 assume as given, a definite difference in pressure between the center 

 and a circle of known radius ; or on the other hand, we can assume 

 that the velocity of the wind is known at a certniu distance from the 

 center. I have chosen the last assumption. 



The wind system may therefore be characterized by the assumption 

 that at a distance of 1000 kilometres from the center the wind velocity 

 shall be 10 metres ])er second. 



According to eqnatiou (29) wlien we put X=k we have 



c F' 1 



If in this we put a? = 10 metres and r = 1000000 metres we then 

 have c E^ = 10000000 ^2 • Since furthermore <'<^m therefore the same 

 equation shows that we must have B > 343.3 kilometres. 



In the selection of appropriate values of c and JR,, another circum- 

 stance is to be considered. The discussion of the formu'he (30) for the 

 velocity go shows that under the assumption here made of A = A-, the 

 maximum velocity of the wind occurs at the boundary of the two 

 regions. The smaller the inner region is chosen, by so much larger 

 results the maximum vek)city cj,.. In the following table some coor- 

 dinate values c, yu, E, and co,. are given. 



Table I. 



II 



Kilometres. 2[ctrespersec. 

 383. 8 26. 06 



420. 4 23. 78 



485. 5 20. 60 



594. r. 10. 82 



