Some aspects of the seasonal variation of carbon dioxide and ozone

An attempt is made to estimate the seasonal source function, Q, of CO₂ on the basis of data for the biosphere, provided by Lieth, and for other sources. The variation of soil respiration appears to be the most uncertain factor. The resulting CO₂ variations in the atmosphere are calculated for horizontal exchange coefficients, K, which vary with latitude. Comparison with observations given by Bolin & Keeling shows that the results are not very sensitive with respect to the assumed variations of Q and of K with latitude. Previous results on the O₃ budget are used to calculate seasonal variations of tropospheric O₃ for stratospheric injection rates, and K values which vary with latitude. It is concluded that tropospheric O₃ may be a useful tracer for the study of the global exchange mechanisms between stratosphere and troposphere, and of related problems.