Using OMPS-LP color ratio to extract stratospheric aerosol particle median radius and concentration with application to two volcanic eruptions

Abstract. We derive stratospheric aerosol microphysical parameters from Ozone Mapping Profiler Suite Limb Profiler (OMPS-LP) satellite measurements using aerosol extinction coefficient ratios at two wavelengths (the color ratio), which is sensitive to the particle radius, and concentration. We estimate various sources of uncertainty in this technique including extinction coefficient measurement error, sensitivity to the size distribution width assumption, and the OMPS-LP algorithm phase function error. We apply our algorithm to extinction coefficient measurements made by the Stratospheric Aerosol and Gas Experiment on the International Space Station (SAGE III/ISS) to verify our approach and find that our results are in good agreement. Our results also compare favorably to balloon borne particle size measurements and concentrations under ambient condition and 2019 Raikoke volcanic eruption assuming a log-normal particle size distribution width of 1.6. We also estimate the changes in aerosol median radius and concentration following the 2019 Raikoke and 2022 Hunga Tonga-Hunga Ha’apai volcanic eruptions and the result is consistent with other retrievals published in the literature.