Shortwave Absorption by Alumina Aerosol Amplifies Stratospheric Warming - Preprint

[Geoengineering News]

https://arxiv.org/html/2509.24246v1

Authors: Taveen Singh Kapoor, Prabhav Upadhyay, Jian Huang, Guodong Ren, John Cavin, Dhruv Mitroo, Joshin Kumar, Jordan A. Hachtel, Lu Xu, Rohan Mishra, Rajan K. Chakrabarty

Abstract

Stratospheric alumina aerosols from rocket launches and geoengineering proposals are presently understood to help counteract greenhouse gas-induced warming by reflecting sunlight and cooling the lower atmosphere. Here, from direct measurement of aerosol absorption cross-sections, we report alumina’s hitherto unknown shortwave absorption characteristics. Alumina’s shortwave absorption could offset up to 10% of its solar-reflective cooling, and if implemented for geoengineering, would warm the stratosphere more than black carbon from rocket launches.

Source: ARXIV