[ESAC Seminar] Shim Yook

“Nuclear War In a World Brimming With Plastic: Impacts of Cl, Br, and Organics on the Ozone Layer”

Previous research has shown that smoke from large-scale fires ignited by regional-scale nuclear detonations can significantly deplete ozone. Our work expands on this by including emissions of halogen-containing compounds – specifically chlorine and bromine – released from the combustion of urban infrastructure and industrial materials. These halogens can become activated on smoke particles produced by a regional nuclear war, making them highly effective at catalyzing ozone destruction.

Using a chemistry-climate model, we assess changes in (1) ozone chemistry and surface climate, and (2) stratospheric circulation. In Part 1, we find that Arctic ozone reductions could reach levels similar to those of the Antarctic ozone hole, up to ~80%. We also obtain ozone losses of 40-60% over mid-latitudes, accompanied by significant increases in surface UV-B radiation. Even a regional nuclear conflict could therefore result in severe ozone depletion and elevated UV exposure, posing serious risks to human health and ecosystems.

In Part 2, we investigate the thermodynamic budget of the stratospheric circulation changes. The nuclear emissions induce substantial stratospheric warming of up to ~30 K. Previously, this was understood as shortwave absorption by injected black carbon (BC) particles. However, our detailed thermodynamic budget analysis shows that the radiative heating is confined to the tropics, while the extratropical and high-latitude anomalies are primarily driven by the dynamical heat transport – via adiabatic processes and atmospheric eddies.

ESAC Early-Career Seminar Series —

A forum for students and postdocs to share recent research, hone presentation skills, and build community among peers, sponsored by the EAPS Student Advisory Committee. Open to current EAPS graduate and undergraduate students and postdocs. Typically hosted on Thursdays during the semester, including pizza lunch.

Contact: esac.officers@gmail.com