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Study on the impact of sunlight on ozone in the atmosphere using solar eclipses

June 12, 2015 (JST)

National Research and Development Agency
Japan Aerospace Exploration Agency (JAXA)
National Institute for Environment Studies (NIES)
Research Institute for Sustainable Humanosphere (RISH)

To what extent do the reduction in solar radiation intensity affect on the ozone concentration in the upper atmosphere? Using high-precision observational data from the superconducting submillimeter-wave limb emission sounder (SMILES) installed on the International Space Station (ISS), a joint research team led by Dr. Koji Imai (JAXA) studied changes in the ozone concentration during a solar eclipse on January 15, 2010. The results showed that in the dark area of the Moon’s antumbra, the ozone concentration in the mesosphere (see Figure 1) was higher compared with those in the area that remained bright, and that the difference depended on the altitude. Owing to lack of accuracy of previous observations, it was difficult to understand dependence of the atmospheric ozone concentration on solar radiation intensity.

Actually, the ozone concentration in the atmosphere is determined by various factors. Among these factors, this study focused on the effect of solar radiation intensity on atmospheric ozone during a solar eclipse. The research team is also studying other factors that determine the ozone concentration in the atmosphere; the ongoing analysis of the SMILES data continues to elucidate the quantitative understanding of production and destruction of ozone in the atmosphere. We expect to predict more accurately the recovery time of the depleted quantity of atmospheric ozone based on high-quality data by SMILES.

Figure 1: SMILES observation during the solar eclipse.
The arrow shows the direction of SMILES observation. The spherical symbols are the SMILES observation points, and the colors indicate the mixing ratio of ozone at the altitude of 64 km (mesosphere).

Paper title: SMILES observations of mesospheric ozone during the solar eclipse
Author:Koji Imai, Takashi Imamura, Kenshi Takahashi, Hideharu Akiyoshi,
Yousuke Yamashita, Makoto Suzuki, Ken Ebisawa, Masato Shiotani
Journal title: “Geophysical Research Letters”