Impact Pattern of Energetic Particle Precipitation on Polar Mesospheric Ozone.

The upper atmosphere of polar regions exhibits two distinct patterns of energetic particle precipitation that can lead to ozone destruction by ionizing the atmosphere: one is the energetic proton precipitation in the polar cap region during solar proton events (SPEs), and the other is the energetic electron precipitations (EEPs) in the auroral oval region from the radiation belt. In this study, we conduct case studies and statistical analyses of ozone observations from the Aura satellite to present the quantitative difference in the impact patterns of SPEs and EEPs on polar mesospheric ozone. According to our statistical analysis of 13 SPEs and 19 EEPs during the MLS time frame, the magnitude of ozone depletion during SPEs is greater than during EEPs. The ozone depletion during SPEs is more pronounced at higher geomagnetic latitudes and negatively correlates with the proton flux, while during EEPs the ozone depletion is more in favor of the geomagnetic latitude band of 60–70° but independent of the electron count rates. In addition, hydroxyl enhancement also exhibits different patterns during SPEs and EEPs, similar to that of ozone depletion. This study further validates the physical link between the magnetosphere and atmosphere and promotes our understanding of the solar influence on Earth's climate. Plain Language Summary: The Earth's middle and upper atmosphere is continuously impacted by charged energetic particles from space. During periods of intense space weather, substantial amounts of protons and electrons are injected into different latitudes of the polar regions, leading to solar proton events (SPEs) and energetic electron precipitations (EEPs). These energetic particles can substantially affect atmospheric components, including hydroxyl and ozone. While previous research has demonstrated the influence of energetic particles on atmospheric components, the different impacts of SPEs and EEPs on ozone depletion and the latitudinal effects have not been thoroughly investigated in a quantitative approach. This study uses ozone measurements from the Aura satellite to conduct case studies and statistical analyses. Our findings indicate that the peak ozone depletion aligns with the precipitation latitudes of protons and electrons during both SPEs and EEPs. In addition, more energetic protons are associated with more severe ozone depletion. Our results suggest that during the selected events, SPEs exert a more significant influence on ozone than EEPs. This research validates the correlation between energetic particles and ozone and enhances our understanding of the solar influence on climate. Key Points: SPEs and EEPs exert distinct latitudinal effects on ozone depletionOzone depletion during SPEs negatively correlates with proton flux, while no significant correlation is found between ozone and ECRsHydroxyl enhancement during SPEs and EEPs presents similar differences in latitudinal distribution [ABSTRACT FROM AUTHOR]