SO2 Diffusion Features of the 2022 Hunga Tonga-Hunga Ha'apai Volcanic Eruptions from DSCOVR/EPIC Observations

Understanding the volcanic SO2 diffusive characteristics can enhance our knowledge of the impact of volcanic eruptions on climate change. In this study, the SO2 diffusion features of the Hunga Tonga-Hunga Ha'apai underwater volcano (HTHH) 2022 eruptions are investigated based on the Deep Space Climate Observatory (DSCOVR) Earth Polychromatic Imaging Camera (EPIC) dataset, which could provide longer term, more consistent, and higher temporal sampling rate observations to complement current low-orbit satellite-based research. SO2 plume major-direction profile analysis indicates that the SO2 diffusion extent of subaerial eruption initiating at 15:20/13 January 2022 was approximately 1500 km in the Southeast-Northwest major diffusive direction by 20:15/14 January 2022 (about 29 h after the HTHH subaerial eruption). All-direction SO2 plume analysis shows that the HTHH subaerial eruption-emitted SO2 plume could diffuse as far as 6242 km by 02:20/15 January 2022. Furthermore, these two analyses in terms of the HTHH major eruption initiating at 04:00/15 January 2022 imply that HTHH major eruption-emitted SO2 plume could diffuse as far as 8600 km in the Southeast-Northwest major diffusive direction by 02:24/18 January 2022 (about 70 h after the HTHH major eruption). It is also implied that HTHH major eruption-emitted SO2 plume could extend to approximately 14,729 km away from the crater by 13:12/18 January 2022. We believe that these findings could provide certain guidance for volcanic gas estimations, thus helping to deepen our understanding of volcanic impacts on climate change.