Members’ Publications

SMILES observations of mesospheric ozone during the solar eclipse

Authors
Imai K., Imamura T., Takahashi K., Akiyoshi H., Ymashita Y., Suzuki M., Ebisawa K., Shiotani M.
Journal
Geophys. Res. Lett., 42(9), 3576-3582
DOI
10.1002/2015GL063323
Abstract

The Superconducting Submillimeter-Wave Limb-Emission Sounder (SMILES) successfully observed vertical distributions of ozone (O3) concentration in the middle atmosphere during the annular solar eclipse that occurred on 15 January 2010. In the mesosphere, where the photochemical lifetime of O3 is relatively short (approximately 100 s), altitude-dependent changes in O3 concentration under reduced solar radiation and their temporal variations were clearly observed as a function of the eclipse obscuration. This study reports the vertical distributions of mesospheric O3 during a solar eclipse event and analyzes theoretically the eclipse-induced changes. We show that simple analytical expressions for O3 concentration, which assume that O3 and O are in a photochemically steady state, can be used to describe the O3 concentration under reduced solar radiation. The SMILES data obtained during the eclipse provide a unique opportunity to test our current understanding of mesospheric O3 photochemistry.