RUSSIAN JOURNAL OF EARTH SCIENCES, VOL. 21, ES5006, doi:10.2205/2021ES000771, 2021
Drabindra Pandit, Narayan P. Chapagain, and Binod Adhikari
This work examines the coupling between solar wind interplanetary magnetic field (IMF Bz) and auroral electrojet (AE) index during supersubstorms (SSSs) of 11 April 2001 and 24 November 2001. The SSSs are particularly intense substorms with the value of SML < -2500 nT; AL < -2500 nT. For the detail analysis, the data set of 1 min time resolution of IMF Bz and AE index in the geocentric solar magnetospheric (GSM) coordinate system are used. The spectral characteristics of SSSs events are studied using continuous wavelet transforms (CWT) and global wavelet spectrum (GWS). The cross-correlation analysis also has been applied to study the correlation and time lag between IMF Bz and AE index. The spectrum identified the main periodicities of the IMF Bz and AE index during these events. The short-lived periodicity of high-frequency signals are identified between 70 to 256 minutes and 80 to 256 minutes during 11 April 2001 and 24 November 2001, respectively. The global wavelet spectrum (GWS) identifies the most energetic periods are present during the SSSs. Cross-correlation analysis shows that the AE index correlates (correlation coefficient ~ -0.6) with IMF Bz at time lag of approximately zero. These results support the previously existing facts that the magnetic reconnection between southward directed IMF Bz and the northward pointed Earth's magnetic field at the dayside magnetopause is the primary mechanism for transferring solar wind energy into magnetosphere and ionosphere during the SSSs events.
Received 24 June 2020; accepted 17 May 2021; published 4 November 2021.
Citation: Drabindra Pandit, Narayan P. Chapagain, and Binod Adhikari (2021), Analysis of the solar wind IMF Bz and auroral electrojet index during supersubstorms, Russ. J. Earth Sci., 21, ES5006, doi:10.2205/2021ES000771.
Copyright 2021 by the Geophysical Center RAS.