PRESSURE GRADIENT 1 



PRESSURE GRADIENT 2 



MBS 

 5i 



-5 



-IQJ- 



PRESSURE GRADIENT 



,y:s ^ 



\ 



I F I M ' A ' M ' J 

 13 15 15 15 15 15 



PRESSURE GRADIENT 

 4 



NORMAL 



1973 



Figure 31.— Pressure Gradients 1-4. 



