Geomagnetic Field Disturbances with Solar Features  and Solar Wind Plasma Parameters During The  Period of 2009–2012

Omkar Prasad Tripathi; P. L. Verma

Volume : III, Issue : V, May - 2013

Geomagnetic Field Disturbances with Solar Features and Solar Wind Plasma Parameters During The Period of 2009–2012

Omkar Prasad Tripathi, P. L. Verma

Abstract :

We have studied geomagnetic storms (Dst ≤ – 80nT) observed during the period of 2009–2012, with halo and partial halo coronal mass ejections ,X–ray solar flares ,interplanetary shocks and disturbances in solar wind plasma parameters . We have found that 81.25% geomagnetic storms are associated with halo and partial halo coronal mass ejections. The association rate of geomagnetic storms with halo and partial halo coronal mass ejections are found 61.54% and 38.46% respectively. We have found positive correlation with correlation coefficient 0.69 between magnitude of geomagnetic storms and speed of associated CMEs. Further we have observed that geomagnetic storms are also associated with X ray solar flares of different categories. The association rate of B–class, C–class and M–class X–ray solar flares are found 20.00%, 40.00% and 40.7% respectively. Majority of the geomagnetic storms 68.75% have been found to be associated with interplanetary shocks .From the study of geomagnetic storms with storms in solar wind plasma parameters we have determined positive co–relation between magnitude of geomagnetic storms and peak values of associated storm in solar wind plasma parameters with co–relation co–efficient, 0.72 between magnitude of geomagnetic storms and peak values of associated storms in interplanetary magnetic field, 0.28 between magnitude of geomagnetic storms and peak value of associated solar wind plasma temperature, 0.24 between magnitude of geomagnetic storms and peak value of associated solar wind plasma pressure.