Japan Geoscience Union Meeting 2018

Presentation information

[EE] Oral

P (Space and Planetary Sciences) » P-EM Solar-Terrestrial Sciences, Space Electromagnetism & Space Environment

[P-EM13] Study of coupling processes in solar-terrestrial system

Sun. May 20, 2018 10:45 AM - 12:15 PM 304 (3F International Conference Hall, Makuhari Messe)

convener:Mamoru Yamamoto(Research Institute for Sustainable Humanosphere, Kyoto University), Yasunobu Ogawa(National Institute of Polar Research), Satonori Nozawa(名古屋大学宇宙地球環境研究所, 共同), Akimasa Yoshikawa(Department of Earth and Planetary Sciences, Kyushu University), Chairperson:Ogawa Yasunobu, Nozawa Satonori

11:45 AM - 12:00 PM

[PEM13-09] Horizontal temperature gradients in the polar upper mesosphere and lower thermosphere above Tromsoe, Norway

*Satonori Nozawa1, Takuya Kawahara2, Takuo T. Tsuda3, Hitoshi Fujiwara4, Norihito Saito5, Satoshi Wada5, Yasunobu Ogawa6, Toru Takahashi6, Yasunobu Miyoshi7, Chris Hall8, Asgeir Brekke8 (1.Institute for Space-Earth Environment Research, Nagoya University, 2.Faculty of Engineering, Shinshu University, 3.Department of Computer and Network Engineering, The University of Electro-Communications, 4.Faculty of Science and Technology, Seikei University, 5.Photonics Control Technology Team, RIKEN Center for Advanced Photonics, 6.National Institute of Polar Research, 7.Department of Earth and Planetary Sciences, Faculty of Sciences, Kyushu University, 8.UiT, The Arctic University of Norway)

Keywords:Horizontal temperature gradients, polar MLT, sodium LIDAR, EISCAT, Tromsoe

Based on about 2700 hours of temperature data obtained with the Tromsoe sodium LIDAR, we have investigated horizontal temperature differences (i.e. temperature gradient) in the polar MLT region between October and March. The sodium LIDAR operated at the EISCAT Tromsoe site (69.6 deg. N, 19.2 deg. E) has a capability of simultaneous five-beam observations; i.e. temperature and sodium density data are obtained simultaneously with good time and altitude resolutions (3 min/500m). In addition to vertical observations, the sodium LIDAR observed volumes of four different directions with azimuth and elevation of (0 deg., 77.5 deg.), (90 deg., 77.5 deg.), (180 deg., 77.5 deg.), and (270 deg., 77.5 deg.) between October 2013 and March 2017, while the elevation angle of 60 degree was set between October 2012 and March 2013, and between October 2017 and March 2018. These configurations allow us to derive horizontal temperature difference between about 80 and 107 km.

We have analyzed (so far) about 184 nights of temperature data sets. The horizontal temperature gradient is found to be in range from about 0.5 K/km to -0.5 K/km for northward and eastward directions, and on average (nighly mean) in range from about 0.05 K/km to -0.05 K/km. We will report temporal and altitude variations of the tempetarure gradient, changes of nightly mean temperature gradients in accordance with SSWs, and comparison with GAIA calculations.