Earth's Nonadiabalic Atmosphere. 529 



radiated from the surface. The incoming radiation, after cer- 

 tain depletions by scattering and absorption in the atmosphere 

 generally, raises the surface of the ground or water to a certain 

 temperature which radiates with long waves. The outgoing 

 radiation passes through three stages : 



(1). In the levels 000 to 2000 meters, where the heat supply 

 is due to radiation at surface temperatures and the heat of con- 

 densation of aqueous vapor. 



(2). In the levels 2000 meters to the isothermal layer, where 

 the radiation is chiefly from the dry air, and there is no addi- 

 tional supply of heat of importance from the condensation. 

 The constant of accelerating loss is about —140. 



(3). In the isothermal layer the radiation is much more 

 rapid, with a constant acceleration of loss of about —362, in 

 spite of the fact that the temperature itself is nearly constant 

 or slightly higher than at the lower boundary of the isothermal 

 region. In Europe the isothermal temperatures are about 202° 

 to 208°, and in the Tropics about 209°, generally, not counting 

 the single observation at Victoria Nyanza. 



It should be noted, in passing, that the thermodynamic data 

 give no support to Abbot's hypothesis of an effective radiation 

 layer at 5000 meters, since the only disturbance in these values 

 is just below and on entering the isothermal layer. The vari- 

 ous hypotheses regarding the origin of the heat found in this 

 layer may properly be revised. There is apparently a con- 

 gested or mixing region on the north side of the high pressure 

 belt, in the temperate latitudes at lower levels, 10,000 to 13,000 

 meters, and over the tropics at higher levels, 13,000 to 15,000 

 meters, and this may be in part due to some form of overflow 

 during the general process of polar circulation. The theory 

 that it is due to such by-products of the incoming radiation as 

 ozone formation is contradicted by the fact that such formation 

 should be able to penetrate to lower levels over the Tropics 

 than over the temperate zones, which is contrary to the entire 

 series of facts. In my opinion the apparent heat of the iso- 

 thermal layer is due to the inability of the radiation to escape 

 fast enough to reach the thermodynamic demands implied in 



(Op. - Qp lc ) (T a - tj, 



although it is observed to carry off heat in the isothermal layer 

 much more rapidly than in the lower levels. That is to say, 

 (Qp a — Cpio) increases so rapidly with the elevation that 

 (T, — T ), the departure of the temperature from stratum to 

 stratum upon which Cp, a depends, cannot proceed rapidly 

 enough by means of radiation losses to give the temperature 

 fall observed in the lower strata. This choking process sets in 

 at a certain low temperature, 202° to 208°, and of course the 



Am. Jour. Sci. — Fourth Series, Vol. XXXIV, No. 204. — December, 1912. 

 35 



