XXIV 



ON THE ENERGY OF STORMS 



BY MAX MARGULES 



[Dated November, igoj.. Translated from the appendix to the annual volume 

 for 1903 of the Imperial Central Institute for Meteorology. Vienna, 1905] 



GENERAL SUMMARY 



When the velocity of the wind is 30 m./sec, the living force or 

 kinetic energy of one kilogram of air is 450 kg. m. 2 sec.~ 2 or nearly 

 equivalent to 0.1 calorie. This amount, which is not large, in 

 comparison with the energy corresponding to the quantities of 

 heat that 1 kg. of air at the surface of the ground receives and loses 

 during one day, does appear very large when we compare it with 

 the energy of a wind of average velocity, such as $m./sec. 



It is not probable that such a very large proportion of the heat 

 communicated to the air is converted into kinetic energy during 

 stormy weather. We shall now seek for conditions of the atmos- 

 phere by virtue of which a sufficient supply of potential energy 

 is stored up to maintain the storm; we shall allow ourselves to 

 be led by experience and will start with the relations between the 

 mechanical and the thermal forms of energy in a gaseous mass. 



§ ( 1 ) A mass of air extending from the ground upward and bounded 

 by a vertical wall (and sometimes even the whole atmosphere) will 

 serve as our closed atmospheric system. For any such system the 

 equation of energy 1 is 



8K + dP + dA + (R) = 



where dK is the increase in the kinetic energy of the system; 



dP is the corresponding change in the potential energy of 

 position, considering gravitation as the only external force; 

 — dA is the work done by the pressural forces; 



'I have taken the liberty of substituting capitals with the superscript 

 dash for the German type used by Margules. — Abbe. 



533 



