tes 
the 
| in 
ity 
ver 
1 is 
SO 
ing 
  
  
s=(v1 +va +v3)/2 (13) 
b=aj-ap (14) 
R=287.054, w=7.292*10-5 
0 is the latitude of the balloon air sounding station. Then we 
cross some pressure layers to calculate another functional 
value RTM' by use of above formulas. Finally we can get a 
functional difference of thickness advection as following: 
RTMM -RTM - RTM' (15) 
Fig.4(a) is an isogram of functional difference of thickness 
advection. 
(5) Isogram of vertical stability of convection 
Generally speaking, when the value of vertical stability of 
convection is as minus, the convection weather will take 
place as possible. So the vertical stability is useful to 
forecast the rain gust. It can be calculated by some complex 
meteorological formulas. 
Fig.4(b) shows us a isogram of vertical stability of 
convection. 
  
  
  
  
  
  
  
  
  
  
  
   
STRERULENF a | RE re. 
Ty ; T } : A JE > 
i. ce fs "n N | f Le P os x | p s Leno d / || 
i / À 4 
  
  
  
  
  
NE (500hpal rice — 12:81: 
d 
SR 
    
  
  
  
  
  
  
  
  
Fig.3 Streamline