Chaurasia et al. (2025) Signature of intraseasonal oscillations during Hunga Tonga volcanic eruption

Identification

• Journal: Advances in Space Research
• Year: 2025
• Date: 2025-12-24
• Authors: A. Chaurasia, A. Guharay
• DOI: 10.1016/j.asr.2025.12.072

Research Groups

• Space and Atmospheric Sciences Division, Physical Research Laboratory, Ahmedabad, GJ, India
• Department of Physics, Indian Institute of Technology, Gandhinagar, GJ, India

Short Summary

This study investigates the impact of the 15 January 2022 Hunga Tonga volcanic eruption on Intraseasonal Oscillations (ISO) using satellite and reanalysis data, revealing enhanced 20–40 day variability in convective parameters and an influence on atmospheric tides.

Objective

• To investigate the impact of the Hunga Tonga–Hunga Ha’apai volcanic eruption on Intraseasonal Oscillations (ISO) using satellite and reanalysis data.

Study Configuration

• Spatial Scale: Local to the Hunga Tonga–Hunga Ha’apai volcano (20.536°S, 175.382°W) for primary ISO analysis, extending to the lower stratosphere for atmospheric tides.
• Temporal Scale: Focused on the period around the 15 January 2022 eruption, analyzing intraseasonal variability in the 20–40 day range.

Methodology and Data

• Models used: Not applicable (analysis based on observational and reanalysis data using wavelet analysis).
• Data sources: Satellite data, reanalysis data. Variables analyzed include Outgoing Longwave Radiation (OLR), Precipitation amount (RF), Specific Humidity (SH), zonal wind (U), Solar F10.7 flux, and DE3 (eastward-propagating diurnal tide with zonal wavenumber 3) amplitude.

Main Results

• Enhanced intraseasonal variability (20–40 days) was observed in Outgoing Longwave Radiation (OLR), Precipitation amount (RF), and Specific Humidity (SH) at the volcano location.
• Estimated eastward phase speeds for these oscillations were 3.6 m/s (OLR), 2.8 m/s (RF), and 3.7 m/s (SH).
• Zonal wind (U) showed no evident response to the event, indicating a possible decoupling of convection and wind.
• No clear impact of solar variability (Solar F10.7 flux) on the observed 20–40 day oscillations was found.
• An appreciable intraseasonal signature was observed in the DE3 (eastward-propagating diurnal tide with zonal wavenumber 3) amplitude in the lower stratosphere, indicating an influence on local convective activity and associated waves.

Contributions

• Provides a novel perspective on how extreme volcanic events can impact atmospheric wave dynamics across varying periods.
• Offers valuable insights into the atmospheric response to powerful volcanic eruptions.

Funding

• Not specified in the provided text.

Citation

@article{Chaurasia2025Signature,
  author = {Chaurasia, A. and Guharay, A.},
  title = {Signature of intraseasonal oscillations during Hunga Tonga volcanic eruption},
  journal = {Advances in Space Research},
  year = {2025},
  doi = {10.1016/j.asr.2025.12.072},
  url = {https://doi.org/10.1016/j.asr.2025.12.072}
}