Upper atmospheric electromagnetic variation caused by lower atmospheric disturbances and its application

2015 Fiscal Year Final Research Report

• Project/Area Number: 25287128
• Research Category: Grant-in-Aid for Scientific Research (B)
• Allocation Type: Partial Multi-year Fund
• Section: 一般
• Research Field: Space and upper atmospheric physics
• Research Institution: Kyoto University
• Principal Investigator: IYEMORI Toshihiko 京都大学, 理学(系)研究科(研究院), 教授 (40144315)
• Co-Investigator(Kenkyū-buntansha): NOSE Masahito 京都大学, 大学院理学研究科, 助教 (90333559) ; TOMIZAWA Ichiro 電気通信大学, 電気通信学部, 准教授 (50111696) ; TAKEDA Masahiko 京都大学, 大学院理学研究科, 助教 (30236484) ; SANO Yasuharu 朝日大学, 経営学部, 准教授 (50257531) ; IGUCHI Masato 京都大学, 防災研究所, 教授 (60144391) ; KOYAMA Yukinobu 京都大学, 大学院理学研究科, 特定研究員 (50598513)
• Co-Investigator(Renkei-kenkyūsha): SHINAGAWA Hiroyuki (独)情報通信研究機構, 電磁波計測研究所, 主任研究員 (00262915)
• Project Period (FY): 2013-04-01 – 2016-03-31
• Keywords: acoustic gravity wave / field-aligned current / ionospheric dynamo / magnetic ripples

Outline of Final Research Achievements

It was shown that the small-scale magnetic variations as observed by low altitude satellites almost always in middle or low latitudes are the manifestation of small (spatial) scale field-aligned currents.We named them as "magnetic ripples". From their seasonal, latitudinal and local-time dependence, geographical characteristics, and ground based magnetic and GPS-TEC observations, it was concluded that they are probably generated by the acoustic mode of atmospheric gravity waves generated by lower atmospheric disturbances.

Free Research Field

太陽地球系物理学