SPARC Hunga-Tonga
Hunga-Ha'apai impacts
open science workshop

SPARC has established a new activity to examine impacts from the January 2022 Hunga Tonga–Hunga Haʻapai eruption (HTHH). The activity began in February 2023, and has completed an initial consultation on an outline structure for the 2025 Hunga-Tonga special report (see below).

HTHH was the most explosive volcanic eruption in the satellite era, and the water-rich plume presents an opportunity to understand the impacts on the stratosphere of a large magnitude explosive phreatomagmatic eruption. The wide range of satellite observations of the early stratospheric plume and its global dispersion will provide measurements to evaluate a range of models for their capabilities to represent stratospheric chemistry, aerosol and dynamics, in this case where both water vapor and aerosol are influencing radiative balances and stratospheric ozone.

There are numerous HTHH eruption observational and modeling studies that have been published, preprints of submitted papers, and new research in early stages. As the dispersed volcanic cloud continues to evolve and its impacts emerge, additional papers will be published. Because of the number and broad range of studies of the HTHH emissions and impacts, a SPARC limited-term cross-activity focused project is being organized to provide a forum for community discussions and synthesis, and to coordinate multi-model assessments. During this 3-year HTHH SPARC activity, the team will co-ordinate research activities and aim to write a special Hunga-Tonga impacts report for publication in late-2025.

The Hunga-Tonga impacts report will directly feed into the upcoming 2026 UNEP/WMO Scientific Assessment of Ozone Depletion report, providing a benchmark synthesis of the impacts from the eruption. Interested scientists in the broader research community are welcomed to be involved in this activity.

Existing SPARC activities such as SSiRC, CCMI and S-RIP are already engaged with HTHH-related studies and will feed into this HTHH activity. The report leads will coordinate with these other SPARC activities, will approach several groups external to SPARC, including Coupled Model Intercomparison Project Phase 6(CMIP6), Past Global Changes Project (PAGES) and International Association of Volcanology and Chemistry of the Earth's Interior (IAVCEI), and will recruit and convene a team comprising both experienced scientists and early career researchers from a range of relevant disciplines for assessing new HTHH findings.

Header photo credit: Photo from 21st Mar 2022 (18:40 AEST), from Noccundra, SW Queensland, Australia (-27.8°,142.6°). (image shared with permission from Dr. Stuart Young, formerly CSIRO, Australia, now retired)

Photo from 26th Feb 2022 (20:37 AEDT), from Canadian Bay, S. Australia (-38.2°,145.1°). (image shared with permission from Dr. Fred Prata, to VolRes mailing list 
https://wiki.earthdata.nasa.gov/display/volres)
https://www.acf.org.au/dr_fred_prata
_volcanoes_climate_and_art

Each of the 2 half-days will have two 2-hour sessions, from 14.00-16:00 and 16:30-18:30 BST (13.00-15:00 and 15:30-17:30 UT).

The 4 sessions will be themed to align with the 7 chapters of the report:

Tue 13:00-15:00 UT “Plume evolution in 1st week after, explosivity, waves & past eruptions” (chapters 1 & 2)

Tue 15:30-17:30 UT “Volcanic cloud progression & hemispheric dispersion (water vapour & aerosol) (chapter 3)

Wed 13:00-15:00 UT “Stratospheric cooling, dynamics and impacts on the 2022 ozone layer” (chapters 4 & 5)

Wed 15:30-17:30 UT “Radiative effects, surface cooling & fate of the stratospheric water vapour” (chapters 6 & 7)

Abstract Submission deadline Friday 21 April 2023

Yunqian Zhu
LASP & CIRES/NOAA, USA

Graham Mann
University of Leeds

Paul A. Newman
NASA Goddard, USA

William Randel
NCAR, USA