Observation of stratospheric ozone depletion associated with Delta II rocket emissions

Ozone, chlorine monoxide, methane, and submicron particulate concentrations were measured in the stratospheric plume wake of a Delta II rocket powered by a combination of solid (NH4ClO4/Al) and liquid (LOX/kerosene) propulsio n systems. We apply a simple kinetics model. describing the main features o f gas-phase chlorine reactions in solid propellant exhaust plumes to derive the abundance of total reactive chlorine in the plume and estimate the ass ociated cumulative ozone loss. Measured ozone loss during two plume encount ers (12 and 39 minutes after launch) exceeded the estimate by about a facto r of about two. Insofar as only the most significant gas-phase chlorine rea ctions are included in the calculation, these results suggest that addition al plume wake chemical processes or emissions other than reactive chlorine from the Delta II propulsion system affect ozone levels in the plume.