NO. 8 BAROMETRIC PRESSURE — DUELL AND DUEI.L 2g 



infrared emission of the stratosplicrc wliicli would follow a local 

 turbidity, produced by nuclei. 



A very essential difference between the dissociating an<l nuclei- 

 producing effect of solar particle invasions on the one side, and the 

 allegedly same effect of solar ultraviolet invasions on the other side, 

 might be that the solar ultraviolet photons penetrate much deeper 

 into the earth atmosi)herc than the solar particles. This fact is of 

 great importance in the question of solar effects on the stratospheric 

 ozone layer. As early as 1943 F. Moeller (40) pointed out that 

 a reasonable explanation for the relationship between changes of 

 solar ultraviolet radiation and variations of sea-level pressure would 

 be possible by making the following assumptions : The effective 

 infrared emission of the atmospheric carbon dioxide in the spectral 

 range between 13 and i6,u, which is of importance for the changes in 

 the temperature of the stratosphere and consequently also for changes 

 of sea-level pressure, is highly dependent on the amount of strato- 

 spheric ozone which likewise has a strong absorption band between 

 13 and 16/H, and therefore screens off more or less the emission of 

 tlie lower CO.j. The assumption that the amount of stratospheric 

 ozone is influenced by variations of solar ultraviolet radiation is 

 not unreasonable, and is strongly supported by theoretical con- 

 siderations of r>. Ilaurwitz (41), published in 1946. Haurwitz, 

 too, stresses the important role which must be ascribed to the stra- 

 tospheric ozone in the case of a relationship between solar ultraviolet 

 radiation and sea-level pressure. After respective computations he 

 comes to the conclusion that the likelihood of appreciable pressure 

 variations at the ground produced by solar activity can be asserted 

 and that such pressure variations must be accompanied by substan- 

 tial motions of the air in the troposphere. Nevertheless he notes that 

 the atmosphere will respond differently to the same solar impulse, 

 depending on its initial state. Also O. R. W'ulf (42) emphasizes 

 in recent publications that the heating of the high atmosphere by 

 solar ultraviolet radiation, which is absorbed by the oxygen and 

 ozone, together with the emission processes of the stratosjiheric ozone, 

 carbon dioxide, and perhaps even of the water vaj^or and the oxides 

 of m'trogcn. rej)resent probably the most important causes for the 

 development of meridional pressure gradients. 



.\ brief summary of the different hypotheses which could possibly 

 explain the effect of solar ultraviolet invasions on the stratospheric 

 and tropospheric circulation and large-scale weather situation, is 

 presented in figure 21. 



