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Hunga Tonga-Hunga Ha'apai Impacts Activity

Data

Data Policy

Hunga Tonga-Hunga Ha'apai Volcano Impact Model Observation Comparison (HTHH-MOC) Project is to evaluate the performance of state-of-the-art chemistry climate models (CCMs) under an unusual climate event and to investigate the evolution of volcanic water and aerosols, and their impacts on atmospheric dynamics, chemistry, and climate.

For the HTHH-MOC project this archive of model output is currently being stored at JASMIN. Please send request to Graham Mann to get access. In the coming years, the data archive will be moved to the Centre for Environmental Data Analysis (CEDA) in the United Kingdom. Housing of the archive at CEDA provides for easy access to all interested researchers, and we encourage analysis of the model output by all interested researchers.

To acknowledge the significant efforts by the modelling groups to produce the data, respect the research interests of the modelling groups and to encourage open discussions between researchers analyzing the model output and the modelling groups, by using the HTHH-MOC model output you agree to abide by the HTHH-MOC data access policy outlined below. This policy seeks to strike a balance between protecting and acknowledging the work of the modeling groups and encouraging legitimate use of the data sets.

Note that contact information for the Principal Investigators of participating modelling groups and the appropriate scientific reference for the model description papers for each group can be found on Zhu et al. (2025), Table 4.

Data Access Policy

  1. Above all, users of the HTHH-MOC data are expected to respect the interests of the CCM Principal Investigators (PIs) and their research groups in the interpretation, presentation, and publication of the model output. The best way to achieve this is for a routine line of communication to be opened with the model PIs as collaborators to discuss model output and their research. This guideline implicitly recognizes the complexity of the models and interpretive efforts, and the possibility of ongoing scientific work by the model PIs that has yet to be published or otherwise made available to others.
  2. The HTHH-MOC data policy is released to public in December 2025. Those wishing to use the output from HTHH-MOC model runs within 2 years after the releasing are requested to respect the following:
    • This 2-year policy allows for the free and open use of model output but includes the obligation to offer co-authorship to model PIs on any manuscripts that are submitted for publication during this time. In return, it is expected that model PIs will constructively participate in the analysis and interpretation of the results.
    • Researchers are kindly asked to provide a brief outline of any planned analysis and a list of the model fields that are central to their work to help avoid duplication and conflicts between groups.
  3. After the 2-year period, users should respect the license the data was produced under. It is strongly recommended that users send evaluations, draft presentations, or papers to model PIs and the HTHH-MOC coordinator two weeks before submission for notification and for the possibility to comment within this 2-week period for quality control.
  4. Any publications using the HTHH-MOC data should properly reference the models that were used and include the following acknowledgement:
    "We acknowledge the modeling groups for making their simulations available for this analysis, the Hunga Tonga-Hunga Ha'apai Volcano Impact Model Observation Comparison (HTHH-MOC) for organizing and coordinating the model data analysis activity, and the Centre for Environmental Data Analysis (CEDA) for collecting and archiving the HTHH-MOC model output."
  5. Occasionally, model output contributed to the archive has been found to contain errors of various sorts. Users who find undetected errors in model output are asked to contact the responsible modeling group.
  6. The HTHH-MOC model output is, by default, produced under the Creative Commons Attribution- ShareAlike 4.0 (CC BY-SA 4.0) license. Note, however, that individual modelling groups may choose to make their data available under a different license. Users of the data are expected to respect the license under which the data is made available. If exceptions to the existing license are required for certain uses, please contact the coordinator.

Last modified: Wednesday, 26-Aug-2026 16:19:25 MDT