Potential Stratospheric Ozone Depletion Due To Iodine Injection From Small Satellites

We use the 3-D Whole Atmospheric Community Climate Model to investigate stratospheric ozone depletion due to the launch of small satellites (e.g., CubeSats) with an iodine propulsion system. The model considers the injection of iodine from the satellites into the Earth's thermosphere and suggests a 4-yr timescale for transport of the emissions down to the troposphere. The base case scenario is 40,000 small satellite launches per year into low orbit (100-600 km), which would inject 8 tons I yr(-1) above 120 km as I+ ions and increase stratospheric inorganic iodine by similar to 0.1 part per trillion (pptv). The model shows that this scenario produces a negligible impact on global stratospheric ozone (similar to 0.05 DU column depletion). In contrast, a 100-fold increase in the launch rate, and therefore thermospheric iodine injection, is predicted to result in modeled ozone depletion of up to 14 DU (approximately 2%-7%) over the polar regions.

Automated summary

We used a 3-D Whole Atmospheric Community Climate Model to examine the effects of small satellite launches with an iodine propulsion system on stratospheric ozone depletion. The model suggests that the emissions from these satellites can reach the troposphere within a 4-year timescale. In the base case scenario of 40,000 small satellite launches per year, the impact on global stratospheric ozone is negligible, while a 100-fold increase in launch rate could lead to significant ozone depletion over the polar regions.