. Compendium of meteorology. Meteorology. 296 THE UPPER ATMOSPHERE the same order of accuracy as the Umkehr observations and can show, at least qualitatively, the variations of rate of heating with latitude and season. Calculation of Heating of the Ozone Layer. To calcu- late the heating of the ozone layer resulting from ozone absorption of direct solar radiation, one needs to know (1) the absorption spectrum of ozone, (2) the spectral distribution of solar energy, 2000-3500 A and 4500- 6500 A, and (3) the vertical ozone distribution. With regard to the absorption spectrum of ozone and the sol
. Compendium of meteorology. Meteorology. 296 THE UPPER ATMOSPHERE the same order of accuracy as the Umkehr observations and can show, at least qualitatively, the variations of rate of heating with latitude and season. Calculation of Heating of the Ozone Layer. To calcu- late the heating of the ozone layer resulting from ozone absorption of direct solar radiation, one needs to know (1) the absorption spectrum of ozone, (2) the spectral distribution of solar energy, 2000-3500 A and 4500- 6500 A, and (3) the vertical ozone distribution. With regard to the absorption spectrum of ozone and the solar spectrum, Craig [10] has given estimates based on the most recent and reliable data. Figure 2 gives. E2/n(col sec''cm'^ cmNTP'') Fig. 2.—Variation of E^/n as a function of A'^. Ez/n as a function of N, from (12), for these estimates. For very small values of A'' the exponent in (12) is small, so the exponential term is close to unity; hence E^/n is nearly independent of A'^. The curve then shows a strong variation of E^/n with A'' in the range of path lengths that includes most of the Hartley absorption. When the solar energy in the Hartley region is exhausted, the integration in (12) effectively extends only over the Huggins and Chappuis bands. Here the absorption coefficients are small and, for values of N encountered in the atmosphere, the exponential term in (12) again approaches unity. From this graph the reader can easily find E:,, and hence the heating from (13) at any desired level in the ozone layer and for any assumed solar zenith angle and vertical ozone distribution. COOLING OF THE OZONE LAYER Cooling of the ozone layer results from radiative transfer in the infrared. The atmospheric gases re- sponsible for this cooling are water vapor, carbon diox- ide, and ozone. Several factors make calculations of the rate of cooling inherently more complex than calcula- tions of the rate of heating. In the first place, the infra- red radiation that affects a given level or
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