Solar wind plasma flows and their space weather aspects

Solar transients like CME’s, solar flares, coronal holes etc. are responsible for initiating short - term and long - term variations in earth’s magnetosphere. As a result geomagnetic disturbances are driven by the interaction of solar wind features with the geo - magnetosphere and furthermore modulating the space environment. The strength of this modulation depends upon the magnitude and orientation of the IMF and solar wind parameters. These interplanetary transients are large scale structures containing plasma and magnetic field expelled from the transient active regions of solar atmosphere. These are the fast magnetized plasmoids moving away from the Sun in to interplanetary space. As they come to interplanetary medium the interplanetary magnetic field drape around them. This field line draping was thought as possible cause of the characteristic eastward deflection and giving rise to geomagnetic activities as well as produce the modulation effects in the near Earth environment. The Solar cycles 23 and 24 have exhibited the unique variation profile. Selecting such transients, occurred during the interval of these cycles, an attempt has been made to determine quantitative relationships of these transients with solar/ interplanetary and Geophysical Parameters. In this work we used hourly values of IMF data obtained from the space born instruments and Omniweb data Center. The analysis mainly based on looking into the effects of these transients on earth’s magnetic field. The high-resolution data IMF Bz and solar wind data obtained from WDC-A, through its omniweb, available during the selected period. Dst and Ap obtained from WDC-Kyoto are taken as indicator of geomagnetic activities. It is found that Dst index, solar wind velocity, proton temperature and the Bz component of magnetic field have higher values and increase just before the occurrence of these events. Larger and varying magnetic field mainly responsible for producing the short-term changes in geomagnetic intensity are observed during these events associated with coronal holes.