NO. 8 



WATER-VAPOR TRANSPARENCY FOWLE 



51 



aqueous vapor from 0.6 cm. to over 3 cm. ppt. H2O was thus 

 obtained. Except in the band probably due to ozone at about 10.3 /a 

 no systematic change appeared in this region of spectrum (see fig. 13) 

 and thus great transparency was indicated. This band at 10.3 /x 

 systematically deepens with increasing air-mass. 



G. COLLECTED RESULTS ON ATMOSPHERIC ABSORPTION FOR LONG-WAVE 



RADIATION 



Table 13 contains a summary of the results on the absorptive 

 power of atmospheric water vapor and their application to determine 

 the total radiation outwards vertically to space from the earth when 

 the atmosphere contains 0.003, 0.03, 0.3 and 3.0 cm. precipitable 

 water. The effect of carbon dioxide and the band of unknown 

 origin at about 10 /x has been included : 



In accordance with the values given in the last line of the table 

 the vertical transmissions of the earth's radiation are therefore 51, 

 43, 34, and 25 per cent, corresponding to 0.003, 0-03> 0-3. a-^d 3 cm. 

 ppt. H2O. Further, applying these last figures to the transmission 

 of radiation outwards in all directions from a horizontal surface at 

 sea-level, assuming Lambert's cosine law, and i cm. ppt. HoO, it 

 is found that 28 per cent of the earth's radiation under such circum- 

 stances passes directly out to space. 



