The Magnetic Storm of August 25-26, 2018: Dayside High Latitude Geomagnetic Variations and Pulsations
Abstract
The features of daytime high latitude geomagnetic disturbances and geomagnetic pulsations during the recent strong magnetic storm on August 25-26, 2018, which occurred at the end of the decline phase of the 24th solar activity cycle with a very low level of solar flare activity, are considered. As a rule, during this phase of the solar activity cycle, magnetic storms are caused by high-speed solar wind flows from coronal holes; however, the magnetic storms during the decay of the 24th cycle were caused by coronal mass ejections (CMEs). It was shown that, despite very weak disturbances on the Sun and a low solar wind speed, a rather strong magnetic storm occurred in the Earth's magnetosphere in August 2018 (Dst = -171 nT). The storm SC with a slight (~25 nT) jump in the Dst index caused quite intense daytime geomagnetic pulsations ipcl at the latitudes of the possible position of the daytime polar cusp. A feature of the recovery phase of this storm was the development of a magnetosphere substorm on a global scale, i.e., the appearance of a negative magnetic bay recorded simultaneously in the auroral night sector and in the polar latitudes of the day sector. A possible interpretation is considered.
- Publication:
-
Geomagnetism and Aeronomy
- Pub Date:
- February 2020
- DOI:
- 10.1134/S0016793219060070
- Bibcode:
- 2020Ge&Ae..59..660K