Exploring the common origins of the Forbush decrease phenomenon caused by the interplanetary counterpart of coronal mass ejections or corotating interaction regions

Abstract

The interplanetary counterpart of coronal mass ejections (ICMEs) and the interaction regions of slow fast solar wind (CIRs) have both been known as potential drivers of Forbush decrease (FD). However, reported studies often take an independent approach for investigating FD caused by ICMEs and CIRs, since both the structures show different signature in in-situ observations. In this paper, we explore the common origin of the FD profile caused by these two large scale structures, within the framework of a diffusion convection model. As a case study, we present one event of each type, in both of which, the solar wind is the most prominent driver. Possible extensions of this model could incorporate other parameters such as magnetic field strength, turbulence, etc which influence the observed FD features. This attempt could help to resolve the complex problem of the diversity in observed FD profiles.