Global implications of ozone loss in a space shuttle wake

Existing global model calculations of ozone depletion due to solid-fueled rocket motor (SRM) launches [Prather et al., 1990; Jackman et al., 1998] take into account the effect of globally dispersed chlorine emissions and ignore the ozone loss in the rocket wake. This ozone depletion in the wake could be substantial (up to 100% in the lower stratosphere during the first hour after exhaust [Ross et al., 1997a, 2000]). In this paper, we provide an estimate of whether wake ozone loss could accumulate after each SRM launch, leading to a larger ozone depletion on the global scale. To address this issue, we estimate an upper bound of the ozone loss in a space shuttle wake and use the Atmospheric and Environmental Research, Inc. two-dimensional model to simulate the global effect. For the scenarios considered, the global impact of the localized ozone loss in the wakes is at least an order of magnitude less than the effects from global dispersion of the SRM chlorine emissions alone ton the order of 10(-3)-10(-4) % versus 10(-2) % in the ozone column near 30 degreesN). Additional sensitivity studies performed for different wake dilution rates, seasons, locations, and local times of the shuttle launches and accounting for chlorine activation via ClONO2 + HCl + Cl-2 + HNO3 on alumina particles did not change this conclusion.