Predicting geo-effectiveness of CMEs with EUHFORIA coupled to OpenGGCM

<div> <p>The <strong>EU</strong>ropean <strong>H</strong>eliospheric <strong>FOR</strong>ecasting <strong>I</strong>nformation <strong>A</strong>sset (<strong>EUHFORIA</strong>, Pomoell and Poedts, 2018) is a physics-based heliospheric and CME propagation model designed for space weather forecasting. Although EUHFORIA can predict the solar wind plasma and magnetic field parameters at Earth, it is not designed to evaluate indices like Disturbance-storm-time (Dst) or Auroral Electrojet (AE) that quantify the impact of the magnetized plasma encounters on Earth’s magnetosphere. To overcome this limitation, we coupled EUHFORIA with <strong>Open</strong> <strong>G</strong>eospace <strong>G</strong>eneral <strong>C</strong>irculation <strong>M</strong>odel (<strong>OpenGGCM</strong>, Raeder et al, 1996) which is a magnetohydrodynamic model of Earth’s magnetosphere. In this coupling, OpenGGCM takes the solar wind and interplanetary magnetic field obtained from EUHFORIA simulation as input to produce the magnetospheric and ionospheric parameters of Earth. We perform test runs to validate the coupling with real CME events modelled using flux rope models like Spheromak and FRi3D. We compare these simulation results with the indices obtained from OpenGGCM simulations driven by the measured solar wind data from spacecrafts like WIND. We further discuss how the choice of CME model and observationally constrained parameters influences the input parameters, and hence the geomagnetic disturbance indices estimated by OpenGGCM. We highlight limitations of the coupling and suggest improvements for future work. </p> </div>