Hunga Tonga-Hunga Ha'apai Impacts Activity

HTHH Model Observations Comparison (HTHH-MOC)

HTHH-MOC timeline

Model Experiments Summary

Experiment 1 - Free-run ensemble experiment from 2022 to 2031. a) Base case (no eruption); b) H2O (~150 Tg) & SO2 (0.5 Tg); c) Only H2O (~150 Tg). d): Only SO2 (0.5 Tg) - aerosol-focused models.

  1. Understand the general evolution of water vapor and aerosol in free-running models;
  2. Quantify HTHH effects on stratospheric temperatures, dynamics, and transport;
  3. Understand the impact of dynamic changes on ozone chemistry;
  4. Quantify the net radiative forcings;
  5. The surface impact such as temperature, ENSO, and monsoon precipitation. - Coupled ocean models required (optional)

Experiment 2a – Nudged winds (& temperature). Model simulated aerosols

Experiment 2b – Nudged winds (& temperature). Prescribed aerosols using GloSSAC retrieval

  1. Analyze H2O & aerosol evolution (Chapters 3 & 6);
  2. Quantify the net radiative forcings (Chapter 7);
  3. impacts on mid-latitude and polar O3 chemistry (Chapter 5).

    4. The data analysis can be designed to do inter-model comparisons, as well as inter-experiment comparisons. The inter-comparisons between Exp 2a and 2b can also help to understand how well we simulate the sulfate SAD and if SAD variation matters for stratospheric O3 chemistry. Comparing Exp1 and Exp2 for the same period can help to understand radiative forcing and radiative effects.

Experiment 3 - Initial plume evolution as short as 1 day and up to 1 or 2 months for chapters 2: radiation and descending of the plume and in-plume chemistry (first month).

Experiment 4 - Free-run ensemble experiment from 2022 to 2031 using the first 5 years of experiment 1 (models resolving the upper atmosphere) for chapters 6. Understand climate impact on the mesosphere and ionosphere from 2022-2027, such as gravity wave drags, temperature changes, PMCs, and atmospheric circulation.

Experiment 5 - Free-run ensemble for mesospheric dynamic response during the first 3 days for chapters 6: Understand mesospheric response during the initial injection of the Hunga Tonga injection, such as gravity wave and lamb wave propagation.

Participated Models

Last modified: Monday, 12-Feb-2024 16:11:12 MST