Cross-correlation and cross-wavelet analyses of the solar wind IMF <i>B</i><sub><i>z</i></sub> and auroral electrojet index AE coupling during HILDCAAs

Abstract : Solar-wind-geomagnetic activity coupling during high-intensity long-duration continuous AE (auroral electro-jet) activities (HILDCAAs) is investigated in this work. The 1 min AE index and the interplanetary magnetic field (IMF) B z component in the geocentric solar magnetospheric (GSM) coordinate system were used in this study. We have considered HILDCAA events occurring between 1995 and 2011. Cross-wavelet and cross-correlation analyses results show that the coupling between the solar wind and the magneto-sphere during HILDCAAs occurs mainly in the period ≤ 8 h. These periods are similar to the periods observed in the in-terplanetary Alfvén waves embedded in the high-speed solar wind streams (HSSs). This result is consistent with the fact that most of the HILDCAA events under present study are related to HSSs. Furthermore, the classical correlation analysis indicates that the correlation between IMF B z and AE may be classified as moderate (0.4-0.7) and that more than 80 % of the HILDCAAs exhibit a lag of 20-30 min between IMF B z and AE. This result corroborates with Tsurutani et al. (1990) where the lag was found to be close to 20-25 min. These results enable us to conclude that the main mechanism for solar-wind-magnetosphere coupling during HILDCAAs is the magnetic reconnection between the fluctuating, negative component of IMF B z and Earth's magnetopause fields at periods lower than 8 h and with a lag of about 20-30 min.
Complete list of metadatas

Cited literature [34 references]  Display  Hide  Download

https://hal-insu.archives-ouvertes.fr/insu-01976498
Contributor : Nathalie Pothier <>
Submitted on : Thursday, January 10, 2019 - 10:05:58 AM
Last modification on : Thursday, July 25, 2019 - 4:16:03 PM
Long-term archiving on : Thursday, April 11, 2019 - 3:00:23 PM

File

angeo-36-205-2018.pdf
Publisher files allowed on an open archive

Identifiers

Collections

Citation

Adriane Marques de Souza, Ezequiel Echer, Mauricio Bolzan, Rajkumar Hajra. Cross-correlation and cross-wavelet analyses of the solar wind IMF <i>B</i><sub><i>z</i></sub> and auroral electrojet index AE coupling during HILDCAAs. Annales Geophysicae, European Geosciences Union, 2018, 36 (1), pp.205-211. ⟨10.5194/angeo-36-205-2018⟩. ⟨insu-01976498⟩

Share

Metrics

Record views

40

Files downloads

91