Joint observations of the large-scale ULF wave activity from space to ground associated with the solar wind dynamic pressure enhancement  

作　　者：SUN XiaoYing HU YunPeng ZHIMA Zeren DUAN SuPing LV FangXian SHEN XuHui 

机构地区：[1]National Institute of Natural Hazards,Ministry of Emergency Management,Beijing 100085,China [2]School of Space and Environment,Beihang University,Beijing 102206,China [3]State Key Laboratory of Space Weather,National Space Science Center,Chinese Academy of Sciences,Beijing 100190,China

出　　处：《Science China(Technological Sciences)》2024年第7期2215-2229,共15页中国科学（技术科学英文版）

基　　金：supported by the National Key Research and Development Program of China (Grant No. 2023YFE0117300);the National Natural Science Foundation of China (Grant No. 4187417);the APSCO Earthquake Research Project Phase Ⅱ, and the Dragon 5 Cooperation 2020-2024 (Grant No. 59236)。

摘　　要：This study reports the rare ultralow-frequency(ULF) wave activity associated with the solar wind dynamic pressure enhancement that was successively observed by the GOES-17(Geostationary Operational Environmental Satellite) in the magnetosphere, the CSES(China Seismo-Electromagnetic Satellite) in the ionosphere, and the THEMIS ground-based observatories(GBO) GAKO and EAGL in the Earth's polar region during the main phase of an intense storm on 4 November 2021. Along with the enhanced-pressure solar wind moving tailward, the geomagnetic field structure experienced a large-scale change. From dawn/dusk sides to midnight, the GAKO, EAGL, and GOES-17 sequentially observed the ULF waves in a frequency range of0.04–0.36 Hz at L shells of ~5.07, 6.29, and 5.67, respectively. CSES also observed the ULF wave event with the same frequency ranges at wide L-shells of 2.52–6.22 in the nightside ionosphere. The analysis results show that the ULF waves at ionospheric altitude were mixed toroidal-poloidal mode waves. Comparing the ULF waves observed in different regions, we infer that the nightside ULF waves were directly or indirectly excited by the solar wind dynamic pressure increase: in the area of L-shells~2.52–6.29, the magnetic field line resonances(FLRs) driven by the solar wind dynamic pressure increase is an essential excitation source;on the other hand, around L~3.29, the ULF waves can also be excited by the outward expansion of the plasmapause owing to the decrease of the magnetospheric convection, and in the region of L-shells ~5.19–6.29, the ULF waves are also likely excited by the ion cyclotron instabilities driven by the solar wind dynamic pressure increase.

关 键 词：ultralow-frequency(ULF)wave solar wind dynamic pressure(P_(sw)) magnetic field line resonance(FLR) ion cyclotron instability 

分 类 号：P353.8[天文地球—空间物理学]