Subject Index 



A-unit (potential refractivity), 16-20, 78-79, 166-170, 189-194, 197, 211, 213-227, 379 



Absolute humidity, 270, 272, 275, 277-280, 286-290 



Absorption coefficient (see also Van Vleck's absorption formulas), 272 



Adiabatic refractivity decrease, 258-262 



dry, 261 



wet, 262 

 Adiabatic temperature lapse rate, 133, 258 

 Advection, 132, 201, 205, 213, 319 



definition, 132 



relative to duct formation, 133, 135 

 Air masses, 79, 102, 114, 119, 123, 163-164, 167-169, 173-176, 179-181, 191, 195- 



197, 201, 213, 221-222 



refractive characteristics of, 163, 169-170, 174-175, 211 

 Angle of penetration (critical angle), 137, 140, 142, 376 

 Apparent height, 360 

 Apparent range, 51, 335, 357-360 

 ARDC Standard Atmosphere, 64 

 Attenuation of radio waves, 269-309 



by fog, 303 



by gases, 270-290 



by hail, 302-303 



by rain {see also Climatology), 292-297 



in clouds, 291 



B 



B-unit, 14-15, 17-20, 189-191, 195 



Barium fluoride strip, 26 



Bending of a radio ray (see also Refraction) 



definition, 49 



methods of computing and predicting, 53-81, 375-393 

 Bi-exponential model 



for absorption, 283, 307 



for refractivity, 311-322 

 Birnbaum refractometer, 31, 33-34 

 Bright band, 303 



C 



Caustic, 148 



Climatic types, relation to Na, 102-104 



Climatology, 89-172 



of ground based radio ducts, 42-43, 132-145 



of refractivity, A^, near the ground (No), 89-109, 111-128, 404-420 



of rainfall attenuation, 297-302 

 Clouds, attenuation in, 291 

 Cold front (see Frontal zone) 

 Composite parameter, 238 

 Continental cross sections of No, 122-128 



Continental arctic air mass (see also Continental polar air mass), 102, 316 

 Continental polar air mass, 79, 123, 163-164, 169, 174-176, 179-180, 196-197, 



221-222, 319 

 Continental tropical air mass, 79, 167-169, 175, 179 

 Convergence 



centers of, 182, 240-241 



influencing atmospheric refractivity, 182-185, 240 

 Core climate, 129 



425 



