日本地球惑星科学連合2023年大会

講演情報

[E] 口頭発表

セッション記号 P (宇宙惑星科学) » P-EM 太陽地球系科学・宇宙電磁気学・宇宙環境

[P-EM12] Coupling Processes in the Atmosphere-Ionosphere System

2023年5月22日(月) 09:00 〜 10:15 101 (幕張メッセ国際会議場)

コンビーナ:Liu Huixin(九州大学理学研究院地球惑星科学専攻 九州大学宙空環境研究センター)、大塚 雄一(名古屋大学宇宙地球環境研究所)、Chang Loren(Institute of Space Science, National Central University)、Yue Deng(University of Texas at Arlington)、Chairperson:Yue Deng(University of Texas at Arlington)、Liu Huixin(九州大学理学研究院地球惑星科学専攻 九州大学宙空環境研究センター)


09:00 〜 09:15

[PEM12-21] The Electrojet Zeeman Imaging Explorer (EZIE) Mission

*Jeng-Hwa Yee1、Jesper Gjerloev1、Nelofar Mosavi1、Rafael Mesquita1、Karl Landal2、Patrick Alken3、Viacheslav G. Merkin1、Kareem A. Sorathia1、Larry Kepko5、Wenbin Wang4、Astrid Maute3、Olga K. Verkhoglyadova6、Heikki Vanhamaki7、Richard Larsson9、Patrick Espy10、Dong L. Wu5、Kirsti Kauristie8 (1.Johns Hopkins University, Applied Physics Laboratory、2.Unversity of Bergen、3.University of Colorado, CIRES、4.National Center for Atmospheric Research (NCAR)、5.NASA Goddard Space Flight Center、6.Jet Propulsion Laboratory、7.University of Oulu、8.Finnish Meteorological Institute、9.University of Hamburg、10.Norwegian Unversity of Science (NTNU))

キーワード:Electrojets, Currents, Magnetosphere-Ionosphere Coupling

EZIE, the Electrojet Zeeman Imaging Explorer, is a recently selected NASA Heliophysics mission of opportunity to study the electrojets in the ionosphere. It employs four identical miniaturized radiometers on each of the three 6U CubeSat, flying in a pearls-on-a-string managed formation, to measure, for the first time, the two-dimensional structure and the temporal evolution of the electrojets flowing at altitudes of ~100–130 km. It employs the Zeeman sensing technique from low-earth orbiting satellite to remotely obtain the current-induced magnetic field vectors at ~80 km, an altitude region very close to the electrojet. The four cross-track downward-looking antennae on each satellite measure polarimetric radiances of the Zeeman-splitted 118 GHz O2 thermal emission line and obtain the magnetic signatures of the electrojet based on measured Zeeman splitting spectral properties. This novel measurement technique allows for the remote sensing of the electrojets at four different cross-track locations simultaneously at altitudes notoriously difficult to measure in situ. The compact 118-GHz heterodyne spectro-polarimeters, leveraging technologies demonstrated by TEMPEST-D and CubeRRT; the 6U CubeSat bus heritage includes RAVAN, CAT, TEMPEST-D, and CubeRRT. Differential drag maneuvers are used to manage satellite along-track temporal separation to within 2–10 minutes between adjacent satellite to record the electrojet temporal evolution, eliminating the need for on-board propulsion. The combination of the sensing technique, compact instrument, CubeSat technologies, mission operations, allow EZIE to cost-effectively obtain never-before 'mesoscale' measurements of the electrojets needed to understand how the solar wind energies stored in the magnetosphere are transferred to the thermosphere and ionosphere. In this paper we will present an overview of the EZIE mission, its science objectives, the Zeeman sensing technique employed, and the measurement products to be provided.