72 



TROPOSPHERIC REFRACTION 



h 



1.6 



1.5 



1.4 



(f) 



-z. 



< 1.3 



Q 

 < 



-J 1.2 



1.0 



0.9 



08 



0.7 



200 



300 



400 



500 



Nc 



Figure 3.11. Comparison of t versus Ne as obtained from CRPL reference atmos- 

 pheres — 1958 and 5-year mean radiosonde data for do = 15°, h — ha = 70 km. 



mean A^ profiles with initial N gradients (i.e., — 112/km and — 106/km, 

 respectively) that are significantly greater than would be expected from 

 the AA^ versus A^^ relationship. Both of these stations have an unusually 

 large humidity decrease near the ground. The third point, Santa Maria, 

 Calif., is of interest since it is in relatively good agreement with the refer- 

 ence atmospheres, even though it represents the southern California 

 summer climate which was excluded from the original AN versus Ns 



