This thesis aims to quantitatively analyse the effects of solar wind-magnetosphere-ionosphere (SW-M-I) coupling on the near -Earth space environment and enhance the current understanding of both large and small-scale coupling processes and mechanisms in the SW-M-I system during extreme transient events of supersubstorm and geomagnetic storms.At the first,robust quantitative analyses with regard to the LI-point and network of magnetometer and radars are included in comparative assessments and investigations of different coupling functions and the most significant parameters known to define the SW-M-I coupling. The in situ observations from the MMS, cluster, and THEMIS missions are additionally used to investigate the ion and electron scale coupling during the geomagnetic storm of 31 December 2015.