376 



C. Abbe — Atmospheric Radiation of 







10,0 00. meters. 









3 









8 





V\\\ 



7 









6 

















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\c 



a \ \ 









JB j 

 1 



/ / "^ 





-S0 OC 40 30 20 -1Q +10 20 30 40 +&0° c 



Temperature and, JUtltucle. 



These curves agree with the general tenor of all observations 

 on the temperature of the air, namely that under a cloudy sky 

 the diminution of temperature with ascent is very slight and 

 uniform ; within a cloud the diminution is given by the laws 

 of evolution of latent heat; above all clouds and in all clear 

 air as in areas of high pressure the temperature depends upon 

 the radiation of heat and on the thermodynamic changes of a 

 compressible atmosphere. 



(14.) In addition to the cases recently under discussion 

 between Ferrel and Hann there are other important problems 

 in the mechanics of the atmosphere that are elucidated by the 

 study of radiation. 



(a.) The general circulation of the atmosphere from the 

 equator to the pole can only take place by virtue of the fact 

 that the air which overflows from the equator and from the 

 tropical highs actually loses its heat (not merely diminishes in 

 temperature) and contracts as it cools. Radiation is the only 

 efficient process capable of accounting for the great loss of heat 

 that the atmosphere experiences. Although we are not yet 

 able to state the average amount and law of radiation as depend- 

 ent on temperature and pressure yet it is easy to see that this 

 must be known and must enter into our equations of condition 

 before we can fully account for the phenomena observed in the 

 general circulation of the atmosphere. 



