Published in Journal of Geophysical Research: Atmospheres
June 1, 2022
The Climate and Ozone Impacts of Black Carbon Emissions From Global Rocket Launches
Christopher M Maloney, Robert W Portmann, Martin N Ross, Karen H Rosenlof
First published: 01 June 2022
https://doi.org/10.1029/2021JD036373
- Abstract
Aerosol emissions from spaceflight activities play a small but increasing role in the background stratospheric aerosol population. Rockets used by the global launch industry emit black carbon (BC) particles directly into the stratosphere where they accumulate, absorb solar radiation, and warm the surrounding air. We model the chemical and dynamical response of the atmosphere to northern mid-latitude rocket BC emissions. We initially examine emissions at a rate of 10 Gg per year, which is an order of magnitude larger than current emissions, but consistent with extrapolations of space traffic growth several decades into the future. We also perform runs at 30 and 100 Gg per year in order to better delineate the atmosphere’s response to rocket BC emissions. We show that a 10 Gg/yr rocket BC emission increases stratospheric temperatures by as much as 1.5 K in the stratosphere. Changes in global circulation also occur. For example, the annual subtropical jet wind speeds slow down by as much as 5 m/s, while a 10%–20% weakening of the overturning circulation occurs in the northern hemisphere during multiple seasons. Warming temperatures lead to a ozone reduction in the northern hemisphere by as much as 16 DU in some months. The climate response increases in a near linear fashion when looking at larger 30 and 100 Gg emission scenarios. Comparing the amplitude of the atmospheric response using different emission rates provides insight into stratospheric adjustment and feedback mechanisms. Our results show that the stratosphere is sensitive to relatively modest BC injections.
- Key Points
- The increased stratospheric BC burden from rocket launches warms the stratosphere
- Stratospheric BC-induced heating causes shifts in stratospheric dynamics, year-round NH ozone loss, and a stronger Antarctic ozone hole
- The climate response scales in a near linear fashion with increasing rocket launch emissions
- Plain Language Summary
Emissions from spaceflight activities play an increasing role in the background stratospheric aerosol population. Rockets used by the global launch industry emit black carbon particles directly into the stratosphere where they accumulate, absorb solar radiation, and warm the surrounding air. We model the climate response of the stratosphere to an annual, black carbon emission source from rocket launches. We initially examine an emission rate of 10 Gg per year, an order of magnitude larger than current emissions but plausible within the next two decades based upon recent trends in space traffic growth. We also perform runs at 30 and 100 Gg per year in order to better understand the atmosphere’s response to rocket black carbon emissions. We show that the rocket black carbon increases stratospheric temperatures and changes the global circulation, both of which cause a reduction in the total ozone column, mainly in the northern high latitudes. Comparing the amplitude of the atmospheric response using different emission rates provides insight into stratospheric adjustment and feedback mechanisms. Our results show that the stratosphere is sensitive to relatively modest black carbon injections.
https://agupubs.onlinelibrary.wiley.com/doi/10.1029/2021JD036373
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