721 



TABLE 812.— THE AMOUNT OF SOLAR RADIATION IN DIFFERENT 



SECTIONS OF THE SPECTRUM, ULTRAVIOLET, VISIBLE, 



AND INFRARED 



Calories, min^cm" 2 , Smithsonian scale of 1913 



Average clear day at Miami, Fla. (sea level) precipitable water about 2.00 cm. 

 Average clear day at Montezuma, Chile (altitude 9,000 feet) precipitable water 0.25 cm. 



TABLE 813.— SPECTRAL DISTRIBUTION OF SOLAR 



THE ATMOSPHERE 



RADIATION OUTSIDE 



On the bases of the Smithsonian and other observations, Moon 251 in 1940 proposed a 

 spectral solar-radiation curve at normal incidence outside the atmosphere at the mean solar 

 distance and also a like curve for solar radiation at the earth's surface for air mass 2 

 (Table 815). More recently a rocket observation 252 has given a direct measurement (at 

 55 km) of the ultraviolet spectrum of the sun at wavelengths below 0.34 /u. Since less 

 than 1 percent of atmospheric ozone is above this level, this observation should be closely 

 representative of ultraviolet solar radiation at wavelengths above 0.22 n at the top of the 

 atmosphere. Moon's values for wavelengths above 0.33fi and data from the rocket observa- 

 tion for wavelengths below 0.33/* were used in constructing the table. 



Part 1. — Intensity of solar radiation outside the atmosphere 



251 Moon, P., Journ. Franklin Inst., vol. 230, p. 583, 1940. 



252 Hulbert, E. O., Journ. Opt. Soc. Amer., vol. 37, p. 405, 1947. 



(continued) 



SMITHSONIAN PHYSICAL TABLES 



