Monitoring lower ionospheric perturbations using VLF/LF transmitter signals in polar regions

2016 Fiscal Year Final Research Report

• Project/Area Number: 25400477
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Space and upper atmospheric physics
• Research Institution: The University of Electro-Communications
• Principal Investigator: Hobara Yasuhide 電気通信大学, 大学院情報理工学研究科, 教授 (10303009)
• Co-Investigator(Renkei-kenkyūsha): TANAKA Yasuyuki 広島大学, 宇宙科学センター, 特任助教 (90633941)
• Project Period (FY): 2013-04-01 – 2017-03-31
• Keywords: VLF帯送信電波 / 下部電離層擾乱 / 昭和基地 / 極域 / 粒子降下 / 雷活動 / ガンマ線フレア / 波動・粒子相互作用

Outline of Final Research Achievements

We investigated the lower ionospheric properties based on the magnetic amplitude from the world wide VLF/LF transmitters in Antarctica. Seven transmitter stations were identified from short-term observations on West Ongul Island, which has little electromagnetic interference. During this project, we developed the VLF/LF observation system consisting of orthogonal cross loop, pre- and main amplifiers, A/D signal processing unit, recording unit and observation software. The developed observation system was installed in Syowa base, Antarctica after test observations in Japan. In Syowa base, we successfully identified the two stations and derived the diurnal pattern of the magnetic amplitude during continuous observation over two years despite strong electromagnetic interference. In the future, we will continue analyzing our precious long-term data and study the lower ionospheric response from parameters related to global lightning activity, space weather.

Free Research Field

プラズマ理工学，大気電気学，地震電磁気学