Sustained, near-daily, near-global profiles of stratospheric water vapor, halogen species, and tracers are essential for monitoring ozone recovery, attributing changes to human and natural drivers, and detecting emerging threats, yet these observational capabilities are nearing their end while coverage remains inadequate.

This gap arrives as the stratosphere undergoes rapid, human-forced change and critical questions remain open: (1) What controls wildfire organic aerosol chemistry, and how will future fires affect ozone recovery? (2) What are the long-term consequences of volcanic water vapor injections? (3) How will growing satellite reentry debris alter aerosol and ozone chemistry? (4) What capabilities are needed to understand potential stratospheric aerosol injection deployment? (5) How will stratospheric change impact human health, and what monitoring is required?

This session brings together atmospheric chemists, dynamicists, remote sensing, laboratory experimentalists, and health scientists. Contributions from all platforms (satellite, aircraft, balloon, ground-based) and methodologies (observation, modeling, data assimilation, laboratory) are welcome.

• GC - Global Environmental Change