Testing the validity of a model of propagation and expansion of coronal mass ejections from near the Sun to 1 AU

DI LORENZO, L.; BALMACEDA, L.A.; CREMADES, H.

San Juan

Congreso; Towards Future Research on Space Weather Drivers; 2019

Understanding the evolution of coronal mass ejections (CMEs) from the Sun to the Earth and the underlying mechanisms is of vital importance, given that they are considered the main drivers of severe space weather.  Here we study the propagation and expansion of a CME from the Sun to 1 AU. The kinematics of the CME in the inner and outer solar corona are first determined via 3D forward modeling from STEREO observations. These measurements are then contrasted with the FRIS (Flux Rope Internal State, Wang et al. 2009; Mishra & Wang 2018) model which describes the evolution of the internal thermodynamic properties of CMEs. The model assumes that CMEs behave self-similarly and provides the variation of the polytropic index of the CME plasma, the average Lorentz force and the thermal pressure force inside CMEs during their propagation. We further extrapolate the derived properties to 1 AU and compare them with in-situ measurements to evaluate the validity of the assumptions.