Tomographic Retrievals of Hunga Tonga‐Hunga Ha'apai Volcanic Aerosol

Abstract

The 2022 eruption of the Hunga Tonga‐Hunga Ha'apai volcano caused substantial impacts on the atmosphere, including a massive injection of water vapor, and the largest increase in stratospheric aerosol for 30 years. The Ozone Mapping and Profiler Suite (OMPS) Limb Profiler instrument has been critical in monitoring the amount and spread of the volcanic aerosol in the stratosphere. We show that the rapid imagery from the OMPS instrument enables a tomographic retrieval of the aerosol extinction that reduces a critical bias of up to a factor of two, and improves vertical structure and agreement with coincident lidar and occultation observations. Due to the vertically thin and heterogeneous nature of the volcanic aerosol, this impacts integrated values of aerosol across latitude, altitude, and time for several months. We also investigate the systematic impact of uncertainty in assumed particle size that result in an underestimation of the aerosol extinction at the peak of the volcanic aerosol layer.

Strong Evidence of Heterogeneous Processing on Stratospheric Sulfate Aerosol in the Extrapolar Southern Hemisphere Following the 2022 Hunga Tonga‐Hunga Ha'apai Eruption

“…According to Taha et al (2022), the standard V2.1 OMPS-LP algorithms provide accurate aerosol retrievals as long as the volcanic cloud is below 36 km; our analysis here is confined to the region below ∼33 km (900 K). We also compared the NASA OMPS-LP V2.1 aerosol products with the tomographic retrievals at 745 nm produced by the University of Saskatchewan (USask v1.2; Bourassa et al, 2023). Although the NASA and USask aerosol products show substantial differences at low latitudes below 500 K, those discrepancies have no bearing on our conclusions, and for simplicity only the NASA aerosol data at 869 nm are shown here.…”

The Estimated Climate Impact of the Hunga Tonga‐Hunga Ha'apai Eruption Plume

“…The V2.1 data (Taha et al, 2022) provides the most accurate OMPS-LP aerosol retrieval up to 36 km. Although the extinction measurements by OMPS-LP are generally consistent with those made by SAGE III/ISS, the OMPS-LP algorithm may overestimate the aerosol extinction below the aerosol peak (Bourassa et al, 2023). AOD is computed from OMPS-LP extinction at 600 nm by integrating the extinction from 36 km to the tropopause height included in the OMPS-LP files.…”

Chemistry Contribution to Stratospheric Ozone Depletion After the Unprecedented Water‐Rich Hunga Tonga Eruption

“…The OSIRIS NO 2 observations are converted to NO x using the PRATMO photochemical box model (McLinden et al, 2000;Prather & Jaffe, 1990), following the process described in Dubé et al (2020). Aerosol extinction data are from the University of Saskatchewan OMPS-LP product (Bourassa et al, 2023). These data, derived from a tomographic inversion, provide height-resolved aerosol extinction at 745 nm with a tomographic inversion, with a vertical resolution of 1-2 km.…”

“…(2020). Aerosol extinction data are from the University of Saskatchewan OMPS‐LP product (Bourassa et al., 2023). These data, derived from a tomographic inversion, provide height‐resolved aerosol extinction at 745 nm with a tomographic inversion, with a vertical resolution of 1–2 km.…”