University of Oulu

Norenius, L., Hamrin, M., Goncharov, O., Gunell, H., Opgenoorth, H., Pitkänen, T., et al. (2021). Ground-based magnetometer response to impacting magnetosheath jets. Journal of Geophysical Research: Space Physics, 126, e2021JA029115. https://doi.org/10.1029/2021JA029115

Ground-based magnetometer response to impacting magnetosheath jets

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Author: Norenius, L.1; Hamrin, M.1; Goncharov, O.2;
Organizations: 1Department of Physics, Umeå University, Umeå, Sweden
2Faculty of Mathematics and Physics, Charles University, Prague, Czech Republic
3Space Physics and Astronomy Research Unit, University of Oulu, Oulu, Finland
4Department of Geophysics, The University Centre in Svalbard, Longyearbyen, Svalbard, Norway
5Birkeland Centre for Space Science, Bergen, Norway
Format: article
Version: published version
Access: open
Online Access: PDF Full Text (PDF, 0.9 MB)
Persistent link: http://urn.fi/urn:nbn:fi-fe2021101951545
Language: English
Published: American Geophysical Union, 2021
Publish Date: 2021-10-19
Description:

Abstract

Localized dynamic pressure pulses in the magnetosheath, or jets, have been a popular topic for discussion in recent decades. Studies show that they can propagate through the magnetosheath and impact the magnetopause, possibly showing up as geoeffective elements at ground level. However, questions still remain on how geoeffective they can be. Previous studies have been limited to case studies during few days and with only a handful of events. In this study we have found 65 cases of impacting jets using observations from the Multiscale Magnetospheric mission during 2015–2017. We examine their geoeffectiveness using ground-based magnetometers (GMAGs). From our statistics we find that GMAGs observe responses as fluctuations in the geomagnetic field with amplitudes of 34 nT, frequencies of 1.9 mHz, and damping times of 370 s. Further, the parallel length and the maximum dynamic pressure of the jet dictate the amplitude of the observed GMAG response. Longer and higher pressure jets inducing larger amplitude responses in GMAG horizontal components. The median time required for the signal to be detected by GMAGs is 190 s. We also examine if jets can be harmful for human infrastructure and cannot exclude that such events could exist.

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Series: Journal of geophysical research. Space physics
ISSN: 2169-9380
ISSN-E: 2169-9402
ISSN-L: 2169-9380
Volume: 126
Issue: 8
Article number: e2021JA029115
DOI: 10.1029/2021JA029115
OADOI: https://oadoi.org/10.1029/2021JA029115
Type of Publication: A1 Journal article – refereed
Field of Science: 115 Astronomy and space science
Subjects:
Funding: L. Norenius and M. Hamrin was supported by Vetenskapsrådet (VR) dnr 2018–03623. T. Pitkänen was supported by the Swedish National Space Agency (SNSA) grant 118/17. O. Goncharov was supported by the Kempe Foundation. H. Gunell was supported by the Swedish National Space Agency (SNSA) grant 108/18.
Copyright information: © 2021. The Authors. This is an open access article under the terms of the Creative Commons Attribution-NonCommercial License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited and is not used for commercial purposes.
  https://creativecommons.org/licenses/by-nc/4.0/