228 SYNOPTIC RADIO METEOROLOGY 



[39] Bean, B. R., and G. D. Thayer (1959). CRPL exponential reference atmosphere, 



NBS Mono. 4. 

 [40] Bean, B. R., and E. J. Button (1960), On the calculation of the departures of 



radio wave bending from normal, J. Res. NBS 64D (Radio Prop.), No. 3, 



259-263. 

 [41] Canterbury Project (1951), Vols. I-III (Department of Scientific and Industrial 



Research, Wellington, New Zealand). 

 [42] Bean, B. R., and L. P. Riggs (1959), Synoptic variations of the radio refractive 



index, J. Res. NBS 63D (Radio Prop.), No. 1, 91-97. 

 [43] Bean, B. R., L. P. Riggs, and J. D. Horn (1959), Synoptic study of the vertical 



distribution of the radio refractive index, J. Res. NBS 63D (Radio Prop.), 



No. 2, 249-258. 

 [44] Palmer, C. E. (1957), Some kinem.".!;ic aspects of frontal zones, J. Meteorol. 14, 



No. 5, 403-409. 



