Mysterious geomagnetic response to minor solar wind disturbance: Observations
Masatoshi Yamauchi
Swedish Institute of Space Physics
Abstract.
Geomagnetic spikes of > 200 nT at Kiruna are normally during substorms or Sudden Commencement (SC). If the spike is isolated without following activity (or no CME arrival), such a spike is normally considered as a noise (caused by local construction etc). However, we recently observed REAL "isolated > 400 nT spike†entire morning sectors in high latitudes on 2022-4-15. Surprsingly, solar wind observd by DSCOVR and by SOHO was stable except that density is elevated for nearly half hour, which by itself cannot be the reson for such a geomagnetic spike. Cluster was ideally located that very localized structure in the solar wind. We show these observation.
Any idea of interpretation is welcome.
Created 2022-10-26 11:10:11 by Mats Holmström Last changed 2022-12-02 12:24:14 by Mats Holmström
