which seems to be much too small to cause a significant increase in the middle atmospheric cooling rate. If all of the cooling in this region were due to emission of infrared radiation by CO2, a very rough estimate of the resulting temperature change is ~10-3°K or less. The heating-cooling models described in Sec. 2 were used to confirm this estimate. Carbon monoxide emitted by HLLVs cannot accumulate like CO2 because CO is rapidly oxidized to CO2. Afterburning in the rocket plume should convert most of the emitted CO into CO2 (K. L. Brubaker, Argonne National Laboratory, private communication, 1980). Otherwise, the CO will mix into the atmosphere and be oxidized, principally by reacting with OH, with a rate coefficient —1.4 x 10-13 cm3 sec-1 (8) corresponding to an upper- atmospheric lifetime of tc0 < 1 month. Reactions of CO with O2, O3, HO2, etc., are extremely slow and can be ignored. Inasmuch as stratospheric OH concentrations are as large as — 1 x 107 molecules cm-3 (15), the lifetime of injected CO could be as short as 2 weeks, assuming that OH levels are not greatly disturbed. Carbon monoxide concentration increases would have to exceed 10'° molecules/cm~3 to affect OH concentrations [background amounts of CO in the stratosphere vary from —2 x 1010 molecules cm 3 near 20 km (12 mi) to — 1 x 109 molecules/cm near 40 km (25 mi), based on recent model calculations]. Thus, if significant amounts of CO remained in the rocket plume, the OH abundance near the plume could be reduced by reaction (28). However, OH would also be influenced by the large quantity of water contained in the plume, which might compensate the CO effect. Because the plume would be rapidly diluted with ambient air as it disperses, the OH reaction cycle would begin to deplete CO quite efficiently, perhaps at a rate approaching (or locally exceeding) the global oxidation rate(s) estimated above. It follows that CO perturbations by satellite power system (SPS) rockets will very likely be negligible. This is confirmed by
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