Table 152 441 



TRANSMISSION OF SOLAR RADIATION THROUGH CLOUDS (OVERCAST) 



Haurwitz * made a study of the relation between solar radiation received on a horizontal 

 surface at the ground and the type of cloud present during overcast conditions at Blue Hill, 

 Mass. The diagram shows the results of this investigation, giving the insolation received 

 at the ground as a function of optical air mass for various overcast cloud types. The 

 curve of clear-day insolation was added from an earlier paper. 2 



The table shows the percent of clear-day radiation received for various optical air 

 masses and overcast cloud types. 



Ratio of insolation with overcast sky to insolation with cloudless sky 



Cloud type 



1 Haurwitz, B., Journ. Meteorol., vol. 5, p. 110, 1948. For the effect of snow see Kalitin, N. N., 

 Strahlentherapie, vol. 39, p. 717, 1931. 



s Haurwitz, B., Journ. Meteorol., vol. 2, p. 154, 1945. This paper and Journ. Meteorol., vol. 3, 

 p. 123, 1946, also discuss the insolation as a function of cloud amount and cloud density. 



TRANSMISSION OF SOLAR RADIATION THROUGH CLOUDS (OVERCAST) 

 90 



1.0 



2.0 3.0 



AIRMASS 



SMITHSONIAN METEOROLOGICAL TABLES 



