Stratospheric Aerosol Particle Size Explains Divergent Limb and Solar Occultation Measurements After the Hunga Eruption

The 2022 Hunga eruption significantly perturbed the stratosphere by injecting substantial water vapor and SO₂, drastically changing the aerosol optical depth and particle size. Post-eruption, satellite limb-scattering retrievals of aerosol extinction from Ozone Mapping and Profiler Suite Limb Profiler (OMPS-LP) and Optical Spectrograph and InfraRed Imager System (OSIRIS) diverged from Stratospheric Aerosol and Gas Experiment on the International Space Station (SAGE III/ISS) solar occultation measurements. We demonstrate that this discrepancy stems from the fixed aerosol particle size assumptions inherent to the limb sensor's retrieval algorithms, which are  different than the large particle sizes observed following the eruption.
Using particle size distribution parameters derived from SAGE III/ISS measurements as input to the OMPS-LP and OSIRIS retrievals, we effectively eliminated the bias in retrieved extinction and Aerosol Optical Depth (AOD) compared to SAGE III/ISS. This consistency across the three datasets provides an improved understanding of aerosol distributions in the highly perturbed stratosphere.