The impact of Medium Energy Electrons(MEE) on the mesospheric chemistry, temperature, and dynamics.

The energy transfer from the solar wind to the Earths magnetosphere fuels the Energetic Particle Precipitation (EPP). EPP refers to highly energetic electrons and protons that are accelerated into the atmosphere, mainly in the polar regions. These energetic particles influence the atmospheric chemical composition by producing nitric oxides (NOx) and hydrogen oxides (HOx) which both are associated with an ozone(O3) loss. Auroral electrons (<30 keV) can penetrate to altitudes around the mesopause, where it will produce NOx, which are quite long-lived during polar winter and can be transported down into the lower mesosphere and stratosphere, where it will effectively destroy ozone. The medium energy electrons (MEE), with higher energies (30 keV1000 keV), can penetrate further down into the atmosphere, reaching the lower mesosphere, and increasing the levels of NOx and HOx, which will result in mesospheric and stratospheric ozone loss. While it is hypothesized that an EPP induced change in stratospheric ozone has the potential to modulate the strength of the stratospheric polar vortex and potentially the polar regional surface temperatures, the dynamical impact of the mesospheric O3 reduction in the mesosphere is unclear. Applying the chemistry-climate model WACCM (version 6) in the specified dynamics mode, we investigate the direct impact of MEE on the mesospheric chemistry, temperature, and dynamics in both hemispheres.