Sensitivity of Middle Atmospheric Ozone to Solar Proton Events: A Comparison Between a Climate Model and Satellites

Abstract

Energetic Particle Precipitation (EPP) consists of highly energetic protons, electrons and neutrons that precipitate into the Earth's atmosphere from extra-terrestrial sources. Solar Proton Events (SPEs) is a type of EPP where a large quantity of protons are ejected from the Sun at high energies (10-300-MeV). The SPEs are sporadic but tend to occur more likely during solar maximum. In the near-Earth space, the energetic protons are guided by the Earth's magnetic field to the polar regions, typical energies providing access to 60 E   geomagnetic latitudes (Verronen et al., 2007). Depending on the energy of the protons, they can penetrate into the upper and middle atmosphere, and have a significant direct impact at altitudes above 30 km (Jia et al., 2020). The energetic protons cause ionization and dissociation in the middle atmosphere that ultimately lead to ozone reduction (Sinnhuber et al., 2012).The SPE impact on middle atmospheric odd oxygen,+ O) has been studied since the November 1969 SPE (Weeks et al., 1972), and is generally well known (Funke et al., 2011;Jackman et al., 2001;Seppälä et al., 2004). The SPE-driven O x Edepletion is mainly caused by the increased production of odd hydrogen,

Satellite‐Borne Observations of Ozone Impact by the November 2001 Solar Proton Event

“…A companion paper was made to Kalakoski et al (2020) by comparing its result to observation from Microwave Limb Sounder using the same method and found good consistency in the spatial and temporal extent of the O 3 response (Jia et al, 2020). Recently, a statistical study on the O 3 response to SPEs, using a comprehensive selection of satellite data, found good agreement with the WACCM-D simulation (Nilsen et al, 2021).…”

“…Additionally, the OSIRIS data provided by the Harmonized project were recently used by Nilsen et al. (2021) to perform a statistical study on the O 3 response to SPEs. During the November 2001 SPE, observations are available on the 3rd, 4th, 6th, 7th, 9th, and 10th.…”

“…Observations from OSIRIS have previously been used by Degenstein et al (2005) to analyze the mesospheric O 3 depletion by the Halloween storm SPE. Additionally, the OSIRIS data provided by the Harmonized project were recently used by Nilsen et al (2021) to perform a statistical study on the O 3 response to SPEs. During the November 2001 SPE, observations are available on the 3rd, 4th, 6th, 7th, 9th, and 10th.…”