[P-EM10] Study of coupling processes in solar-terrestrial system

[PEM10-21] Studies of the polar upper atmosphere from comprehensive observations and GCM simulations

*Hitoshi FUJIWARA¹, Satonori NOZAWA², Yasunobu OGAWA³, Ryuho KATAOKA³, Yasunobu MIYOSHI⁴, Hidekatsu JIN⁵, Hiroyuki SHINAGAWA⁵ (1.Faculty of Science and Technology, Seikei University, 2.Solar Terrestrial Environment Laboratory, Nagoya University, 3.National Institute of Polar Research, 4.Department of Earth and Planetary Sciences, Faculty of Sciences, Kyushu University, 5.National Institute of Information and Communications Technology)

Keywords:thermosphere, ionosphere, mesosphere, EISCAT, GCM, Na lidar

The polar upper atmosphere is the window on near-Earth space. Since the energy from the solar wind is poured into the polar upper atmosphere through near-Earth space, we can obtain information of the outer world around the Earth from some observations in the polar region. For example, the auroral phenomena are the typical ones which visualize the variations of the space environments. The polar upper atmosphere is also the mirror for the climate change. Global cooling goes on in the upper atmosphere while global warming is the advancing problem in the troposphere. Since the effects of the global warming propagate upward with increasing their amplitudes with height, some people have tried to understand the global warming or climate change from the signals in the upper atmosphere. In particular, remarkable phenomena, such as the noctilucent cloud, have appeared in the polar upper atmosphere due to the changes in the troposphere. Furthermore, recent studies have clarified the effects of the sudden stratospheric warming (SSW) on temperature and wind variations in the mesosphere, thermosphere, and ionosphere. We overview the relationships between external forcing from above and below and variations of the polar upper atmosphere. Then, the recent progress of our understandings from comprehensive observations and GCM simulations are shown. The future targets in our research project will be also shown in this presentation.