Stratospheric aerosols (SA) are key components of the stratosphere, and small changes in their loading or composition can trigger significant radiative, chemical, and dynamical responses that influence climate and ozone (O 3 ) processes. Motivated by recent volcanic eruptions, extreme wildfires, compound perturbations, and expanding high-altitude human activities, this review synthesizes SA research within an “observation-sources-formation-effects” perspective. We first summarize how ground-based lidar, satellite occultation, limb-scatter measurements, and spaceborne lidar constrain SA vertical structure, optical properties, and perturbation evolution, while also highlighting retrieval limitations that affect cross-platform comparison. We then compare major SA sources, including volcanic eruptions, pyrocumulonimbus driven wildfires, aviation, rocket launches, and spacecraft re-entry, with emphasis on their differences in injection altitude, composition, persistence, and spatiotemporal spread. Building on these source contrasts, we review sulfate-dominated, carbonaceous, mixed, and trace anthropogenic aerosol components, together with the nucleation, growth, and heterogeneous chemical processes that regulate aerosol evolution and O 3 -related impacts. Finally, we assess how sulfate-rich volcanic perturbations, absorbing wildfire smoke, water-rich compound eruptions, and rocket-derived black carbon differ in radiative forcing, dynamical response, and climate persistence. Overall, this review highlights that key uncertainties remain in quantifying mixed source contributions to SA, predicting their long term evolution, and assessing the potential impacts of high altitude anthropogenic emissions. Addressing these uncertainties is important for reducing uncertainties in climate prediction, improving O 3 related risk assessment, and evaluating high-altitude emissions associated with expanding aerospace activities and future space habitation.
Ding et al. (2026) studied this question.