MOVEMENTS OF ATMOSPHERE GULDBERG AND MOHN 167 



In order to study the conditions that obtain on the inside and on 

 the outside of the current between the pressures p and p ' at the 

 surface of the earth and between- the pressures p and p' on the 

 inside and outside of the current at a given altitude, where the ver- 

 tical velocity of, the current is equal to zero, we shall assume that 

 the virtual temperatures T in the current and T' in the surrounding 

 atmosphere decrease proportionally to the altitude. Let m be the 

 coefficient that belongs to the current and m' that belonging to the 

 atmosphere, we have from §4 



IY" = (i__!M" (1) 



T / \ amT / 



*-(£)-- (1--^) 



Po \ T o ' V am' 7 ( ; 



By writing 



_gz_ 



amT n l t T 



1 - _«!_ 



a m' T' 

 we shall have 



'0 



P' Po' 



, W -(IJ. (£)-... co 



/ (*) (4) 



If the movement is ascending it is necessary to have simulta- 

 neously 



^ < 1 and t > 1 



Po P' 



If the movement is descending it is necessary to have simultane- 

 ously 



Po < 1 and t > 1 



Po P' 



Differentiating / (2) we shall find 



T _ T , _g m' - m 

 df («) -f {z)= if {z) _ Jam^m^ ' (g) 



r„r„'(i-^)(i-^ 



\ amT / \ am' 



dz a „ „,. / „ gz \ / . sz 



~T 



