MOVEMENTS IN ATMOSPHERE — GULDBERG AND MOIIN l6q 



We may write 



' T V" = h + 



Po \ T o 



i + 



am Tq 

 am' T ' 



Assuming 



f (z) 



1 + 



gz 



1 + 



amT 



gz 

 am' T ' 



T \ m I T ' \ m ' 



tJ \ v 



FIG. 13 



we shall have 



and the conditions for descending motion are written 



t > 1 and-^ < 1 

 P' Po 



and consequently we must have 



f (*) > 1 



By differentiating /(z) we shall find 



dz 



g_m-m_ 



/' (a) = £ ./(z). 



+ ~ 



a mm 



T V 



(7) 

 (8) 



<9) 



(10) 



We shall distinguish three cases: 



(1) T < T\. For z = o we have /'(z) positive and we conclude 

 then that a descending current can always exist since the virtual 



