Solar Wind Disturbances

ABSTRACT We have studied H-CMEs and II-type radio bursts related intense geomagnetic storm (Dst≤-100 nT) associated with X-ray solar flare, Interplanetary Magnetic Fields and solar wind disturbances, during the period of 2001-2012. We have found that all the II-type related intense geomagnetic storms are associated with X-ray solar flares of different categories. The association rates of class X, class M, class C and class B, X-ray solar flares have been found 18.18%, 54.55%, 18.18 % and 9.09 % respectively. Further we have concluded that intense geomagnetic storms are closely related to inter-planetary magnetic fields and change in solar wind disturbances (temperature and pressure). Positive co-relation with correlation coefficient 0.63 has been found between magnitude of intense geomagnetic storms and magnitude of change in southward com-ponents of interplanetary magnetic field. Further positive co-relation with correlation coefficient 0.63 has been found between magnitude of intense geomagnetic storms and magnitude of change in solar wind plasma temperature and 0.82 between magni-tudes of intense geomagnetic storms and magnitude of change in solar wind plasma pressure