Presentation #106.32 in the session Solar Eruptive Events: Posters.
One of the most fundamental properties of the Sun is its magnetic structure: a combination of closed and open field lines. Coronal holes are the regions of open, unipolar magnetic fields where high-speed solar wind particles are accelerated into interplanetary space, thus play a crucial role in heliophysics as one of the main drivers of geomagnetic activity. Active regions, areas with strong closed magnetic fields which host many eruptive events such as flares, filament/prominence eruptions, coronal mass ejections (CMEs), etc. may cause geomagnetic storms. Understanding how the interaction between the open and closed field regions results in CMEs that cause geomagnetic storms is a fundamental requirement for predicting the effects of the Sun on Earth. In this study, we present a comprehensive observational and modeling of a geo-effective event with Dst index of -80 nT observed on 2011 May 28 when a coronal hole was bordering an active region. We produce 3D magnetic field configurations that are consistent with the observations and employ numerical models to track the CME/ICME propagation up to 1 au. We found that the geomagnetic storm involved two interplanetary coronal mass ejections. From our magnetic models, we found that the presence of a nearby coronal hole made the flux rope unstable at relatively low axial flux values and found a good agreement between the data and both reconstructions, from in situ data to 10 Rsun and from 10 Rsun data to 1 au.