The PI will study, through remote sensing, various disturbances in the polar upper atmosphere over the Cusp Auroral Observatory in Longyearbyen, Svalbard. This research will address two aeronomic problems: (1) the effects of charged particles on thermospheric composition and thermodynamics, and (2) the effects of planetary, tidal and gravity waves on the middle atmosphere and lower thermosphere density and temperature. The unique location of Longyearbyen permits monitoring optical signatures of upper atmospheric disturbances triggered by the magnetospheric particles precipitating in the cusp, LLBL, and poleward boundary of the night sector of the auroral oval, as well as in the polar cap region. Large differences in the average energy of the particles precipitating in these regions lead to optical emissions from distinctly different heights. Absolute intensities of the emissions will provide the necessary database for quantitative assessment of upper atmospheric disturbances. Such data constitute the input needed for detailed numerical auroral model calculations to derive thermospheric temperatures and constituent densities at different heights. Finally, the proposed measurements can determine the dynamical and chemical processes that convert the effects of zonally symmetric non-migrating tides in the polar middle atmosphere and lower thermosphere.
