The main objective is to study short-term modulations of cosmic rays (CRs) caused by their interaction with magnetic flux ropes ejected into the heliosphere by solar eruptions. In particular, the research is focused on the following goals:

1. Prepare a catalogue of galactic cosmic rays decreases (Forbush Decreases, FD) caused by magnetic clouds (MCs) that are not dominated by turbulence in the fore-shock and shock-sheath regions, i.e., preferably to focus on slow Coronal Mass Ejections (CMEs). Among these CMEs are so called stealth CMEs that are characterized by no apparent solar surface association, and therefore have no easily identifiable signature to locate the region on the Sun from which the CME erupted.

2. Model the intensity variation of galactic cosmic rays by solving the Lorentz equation in realistic magnetic fields.

3. Comparison of model results and observation using the in situ measurements of MCs and corresponding Forbush decreases.