Advanced atmospheric temperature measurement techniques using radar meteor echoes

2017 Fiscal Year Final Research Report

• Project/Area Number: 16K13888
• Research Category: Grant-in-Aid for Challenging Exploratory Research
• Allocation Type: Multi-year Fund
• Research Field: Space and upper atmospheric physics
• Research Institution: National Institute of Polar Research
• Principal Investigator: Tsutsumi Masaki 国立極地研究所, 研究教育系, 准教授 (80280535)
• Co-Investigator(Kenkyū-buntansha): 野澤 悟徳 名古屋大学, 宇宙地球環境研究所, 准教授 (60212130)
• Co-Investigator(Renkei-kenkyūsha): OGAWA Yasunobu 国立極地研究所, 研究教育系, 准教授 (00362210)
• Project Period (FY): 2016-04-01 – 2018-03-31
• Keywords: 極域中間圏界面 / 大気温度 / 流星レーダー / 電子温度 / 両極性拡散係数

Outline of Final Research Achievements

Existing ‘absolute’ temperature measurement techniques in the mesopause region using radar meteor echoes need empirical atmospheric parameters such as vertical temperature gradient, which may not always be appropriate. We have developed a technique without need for additional information other than meteor radar data by combining the existence method and the ‘relative’ temperature measurement technique which we developed in 1990s.
In the course of the present study, we have found for the first time that meteor trails in the polar region can diffuse much faster than usual under geomagnetically disturbed conditions. Through comparison with incoherent radar and Na temperature lidar measurements we further found that highly enhanced electron temperature was responsible for the anomalous diffusion. Such electron temperature enhancement in the polar mesosphere has not been known so far, and is expected to be useful for coupling studies between neutral and ionized atmospheres.

Free Research Field

大気物理学