• A study of the passage of high-speed solar wind streams, their plasma/field properties and space weather effects of geomagnetic disturbances

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      https://www.ias.ac.in/article/fulltext/joaa/042/0098

    • Keywords

       

      $D_{\rm st}$; geomagnetic storm; plasma; HSSs.

    • Abstract

       

      This study investigated the geomagnetic disturbances and high-speed solar-wind streams (HSSs) during the period of solar storms emitted from coronal holes. The contemplated long-term HSS observations were taken from 1963 to 2016. On the basis of the intensity of geomagnetic activity, solar storms weredivided into four groups: weak ($-$50 nT < $D_{\rm st}$ < $-$30 nT), moderate ($-$100 nT < $D_{\rm st}$ < $-$50 nT), intense($-$200 nT < $D_{\rm st}$ < $-$100 nT) and superstorms ($D_{\rm st}$ < $-$200 nT). The relationship between solar plasma/field parameters and geomagnetic disturbances was also studied in the course of HSSs. For this purpose, statistical distributions and correlation analyses have been performed during the passage of HSSs causing geomagnetic disturbances on the individual stages. It was found that variations in the magnitude of the magnetic field$B$ (nT) and $V$ (km/s) relative to disturbance storm time ($D_{\rm st}$) index occur oppositely. During intense and super solar storms, the Earth’s magnetic field becomes very weak due to a decrease in the $D_{\rm st}$ index. The annualtime-series analysis suggests that the $D_{\rm st}$ and $K_p * 10$ index are of decreasing trends, whereas $Bz$ (nT) and $Ey$ (mV/m) have increasing trends during the study period. $D_{\rm st}$ best correlates with the $K_p * 10$ index with the highest value of correlation coefficient ($R$) to be observed as 0.54. The value of R is found to be 0.51 between $D_{\rm st}$ and $B$ (nT) during the passage of HSSs.

    • Author Affiliations

       

      SALMAN TARIQ1 HASAN NAWAZ2 FAZZAL QAYYUM2 ZIA UL-HAQ2

      1. Remote Sensing, GIS and Climatic Research Lab (National Center of GIS and Space Applications), Department of Space Science, University of the Punjab, Lahore, Pakistan.
      2. Remote Sensing, GIS and Climatic Research Lab (National Center of GIS and Space Applications), Centre for Remote Sensing, University of the Punjab, Lahore, Pakistan.
    • Dates

       
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