Recent Developments in the Estimation of Potential Effects of High Altitude Aircraft Emissions on Ozone and Climate.
Interim rept. 15 Apr 77-15 Oct 78,
INSTITUTE FOR DEFENSE ANALYSES ARLINGTON VA
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A review is provided of recent December 1976-June 1978 developments in problems associated with estimating the potential effects that aircraft emissions at cruise altitudes may have on the earths protective ozone shield andor surface climate. Background information is provided as deemed necessary for context. The review shows that one recently measured key reaction rateHO2 NO yields NO2 HO has had dramatic effects on the ozone question. Computed effects on the ozone column of nitrogen oxides which, unless in very large quantity, now cause an increase and water vapor emissions which, unless thermal feedback effects are included, cause a decrease from supersonic transports at 17-20 km are now small and, on balance, apparently positive, at least for moderate fleets several hundred aircraft. Subsonic aircraft also appear to cause small increases in the ozone column however, on new modeling results are available. The new HO2 NO rate has affected model duplication of the natural atmosphere adversely another important new rate HO2 O3 yields HO 2 O2, not yet incorporated in available results, may reduce this difficulty. Second-order effects thermal feedback have become important, particularly in modeling water effects the modeling of water transport processes, however, involves many uncertainties. Additional modeling studies are needed. Progress in emissions measurement uncertainties and brief comments on possibly important climatic aspects are also included. Author
- Physical Chemistry
- Air Pollution and Control