Impact of Solar Wind High Speed Streams on Ionospheric Current Systems
- 1Space and Astronomy Research Unit, University of Oulu, Oulu, Finland (marcus.pedersen@oulu.fi)
- 2Finnish Meteorological Institute, Helsinki, Finland
- 3School of Mathematical and Physical Sciences, University of Newcastle, Callaghan, New South Wales, Australia
- 4The Johns Hopkins University Applied Physics Laboratory, Laurel, MD, USA
- 5Faculty for physics and technology, University of Bergen, Bergen, Norway
High speed streams (HSS) and associated co-rotating interaction regions (CIR) in the solar wind are one of the major drivers of geomagnetic activity, especially during declining phases of sunspot cycles and near sunspot minima. We have identified 51 HSS/CIR driven geomagnetic storms that coincide with a Dst drop to less than -50nT during the period 2009-2018 and we investigate their impact on ionospheric current systems. Our approach is to study the evolution of the global scale current systems, i.e. the auroral electrojets and Region-1/2 field-aligned currents (FAC), with the SuperMAG magnetometers and AMPERE satellite data, respectively. The events are studied with a superposed epoch analysis centered at the storm onset to see the general behavior of the current system globally and in four different MLT sectors: noon, dusk, midnight and dawn. A minor enhancement of the integrated FAC was observed in the midnight, dawn and dusk sector 3 hours before the storm onset. The largest FAC and variability was observed in the dusk sector, and the integrated FAC maximum occurred in the middle of the storm main phase, 4 hours before the Dst minimum. This result will be compared to the evolution and behavior of the electrojet currents from superMAG. In the future a similar study will be conducted for ICME geomagnetic storms and compared to the HSS/CIR-related storms.
How to cite: Pedersen, M., Vanhamäki, H., Aikio, A., Käki, S., Viljanen, A., Workayehu, A., Waters, C., and Gjerloev, J.: Impact of Solar Wind High Speed Streams on Ionospheric Current Systems , EGU General Assembly 2020, Online, 4–8 May 2020, EGU2020-18592, https://doi.org/10.5194/egusphere-egu2020-18592, 2020.
