Umeå University's logo

umu.sePublications
Change search
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf
The Delayed Time Response of Geomagnetic Activity to the Solar Wind
Umeå University, Faculty of Science and Technology, Department of Physics.
Umeå University, Faculty of Science and Technology, Department of Physics.
Show others and affiliations
2017 (English)In: Journal of Geophysical Research - Space Physics, ISSN 2169-9380, E-ISSN 2169-9402, Vol. 122, no 11, p. 109-127Article in journal (Refereed) Published
Abstract [en]

We investigate the lagged correlation between a selection of geomagnetic indices and solar wind parameters for a complete solar cycle, from 2000 to 2011. We first discuss the mathematical assumptions required for such a correlation analysis. The solar wind parameters and geomagnetic indices have inherent timescales that smooth the variations of the correlation coefficients with time lag. Furthermore, the solar wind structure associated with corotating interaction regions and coronal mass ejections, and the compression regions ahead of them, strongly impacts the lagged correlation analysis results. This work shows that such bias must be taken into account in a correct interpretation of correlations. We then evidence that the magnetospheric response time to solar wind parameters involves multiple timescales. The simultaneous and quick response of the PC and AE indices to solar wind dynamic pressure with a delay of similar to 5 min suggests that magnetospheric compression by solar wind can trigger substorm activity. We find that the PC and AE indices respond to interplanetary magnetic field (IMF) B-Z with a response time of respectively similar to 20 and similar to 35 min. The response of the SYM-H index takes longer (similar to 80 min) and is less sharp, SYM-H being statistically significantly correlated to the IMF B-Z observed up to more than similar to 10 h before. Our results suggest that the solar wind velocity's dominant impact on geomagnetic activity is caused by the compression regions at the interface of fast/slow solar wind regimes, which are very geo-effective as they are associated with high solar wind pressure and strong interplanetary magnetic field.

Place, publisher, year, edition, pages
AMER GEOPHYSICAL UNION , 2017. Vol. 122, no 11, p. 109-127
National Category
Astronomy, Astrophysics and Cosmology
Identifiers
URN: urn:nbn:se:umu:diva-144364DOI: 10.1002/2016JA023793ISI: 000419938600015Scopus ID: 2-s2.0-85038363228OAI: oai:DiVA.org:umu-144364DiVA, id: diva2:1179861
Available from: 2018-02-02 Created: 2018-02-02 Last updated: 2023-03-24Bibliographically approved

Open Access in DiVA

fulltext(1448 kB)557 downloads
File information
File name FULLTEXT01.pdfFile size 1448 kBChecksum SHA-512
75d20c4c44bc09f5c893dd14bcf5b737e8e8a84751fcc8a447db6d5e9314c3aac73e991447c5cd35a8e58488ceac8ecfd367f7878f539146a23a483a66eba86a
Type fulltextMimetype application/pdf

Other links

Publisher's full textScopus

Authority records

Hamrin, MariaPitkanen, T.

Search in DiVA

By author/editor
Hamrin, MariaPitkanen, T.
By organisation
Department of Physics
In the same journal
Journal of Geophysical Research - Space Physics
Astronomy, Astrophysics and Cosmology

Search outside of DiVA

GoogleGoogle Scholar
Total: 558 downloads
The number of downloads is the sum of all downloads of full texts. It may include eg previous versions that are now no longer available

doi
urn-nbn

Altmetric score

doi
urn-nbn
Total: 332 hits
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf