Reduction of Stratospheric Ozone from High-flying Aircraft, Studied in a Two-dimensional Photochemical Model with Transport

A steady state two-dimensional model of the stratospheric ozone layer is presented. Chemical reactions involving oxygen, hydrogen, and nitrogen are considered along with the effect of a parameterized, two-dimensional transport, by mean motion and by eddies. The model is in reasonable agreement with observed ozone data. The reduction of ozone from emission of NO x from high flying aircraft is studied, assuming a fleet of 500 supersonic aircraft in transatlantic operation, flying at given altitudes. The effect is found to depend critically upon flight level. For mid-latitude, summer, the ozone column density is reduced by 0.3% for a flight level of 18 km. For flight levels of 23 and 28 km the reduction is 2 and 5%, respectively. Accordingly, the increase in u.v. radiation amounts to approximately 0.6, 4, and 10% for the same flight levels.