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Fig. 4 | Earth, Planets and Space

Fig. 4

From: Estimating the solar wind conditions during an extreme geomagnetic storm: a case study of the event that occurred on March 13–14, 1989

Fig. 4

Estimated solar wind parameters and Dst index during the storm that occurred on March 13–14, 1989. Top panel: intensity of the estimated total magnetic field from Geostationary Operational Environmental Satellites (GOES) 06 and 07, represented by blue and red dots, respectively. Second and third panels: estimated geocentric solar magnetospheric (GSM)-Y and GSM-Z components of the magnetic field, respectively. Fourth panel: estimated solar wind speed. Estimations from the 1-h averaged GSM-Z magnetic field and dawn to dusk solar wind electric field (VBs) from the Dst index are plotted as filled circles with error bars. The green filled circles plotted in the top to fifth panels indicate 1-h averaged solar wind parameters at 22–23 UT on March 14 obtained from the OMNI database. The blue line plotted in the fourth panel represents the solar wind speed profile estimated from the maximum solar wind speed at the second SSC and the solar wind speed at 22–23 UT on March 14, also obtained from OMNI data. Fifth panel: number density of the solar wind. Sixth panel: VBs obtained from the Dst index, represented by the thick black line, and VBs obtained from GOES 06 and 07 observations with the estimated solar wind speed, represented by red and blue dots, respectively. Bottom panel: Dst index. The two dotted vertical lines indicate the first and the second storm sudden commencement (SSC), respectively

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