Retrieval of stratospheric aerosol extinction coefficients from OMPS-LP measurements

Abstract. A new retrieval algorithm to obtain vertical profiles of the aerosol extinction coefficient from the measurements of the scattered solar light in the limb viewing geometry made by the OMPS-LP instrument is presented. The method employs the normalization of the limb radiances to the solar irradiance in contrast to the normalization by a limb measurement at an upper tangent height, which is used by most of the other published limb-scatter retrievals. The main advantage of this approach is a nearly complete elimination of the dependence of the retrieval results on the prior aerosol extinction profile used in the retrieval. This makes the retrieval well suitable to analyze the observation scenes with highly elevated aerosol plumes as occurred after the Hunga Tonga-Hunga Ha'apai volcanic eruption in January 2022. The results from the new approach were compared to independent data from SAGE III/ISS and OSIRIS. In general, an agreement within 25 % between the different data products was observed although larger differences were seen after very strong volcanic eruptions and wildfires. The new data product was used to investigate the evolution of the aerosol plume after the Hunga Tonga-Hunga Ha'apai volcanic eruption.