| Abstract : | Coronal mass ejections(CME) are the large-scale sporadic eruption of dynamically evolving plasma structure, carrying a frozen-in magnetic flux from the solar corona into the heliosphere. By studying the CMEs, we can understand the physical process responsible for the ejection of plasma structure from the solar corona, also the kinematic and thermodynamic evolution of the expanding magnetized plasma in the heliosphere. As practical importance, they are the main drivers of severe space weather and are responsible for geomagnetic storms. The evolution of the kinematic properties of CMEs has been studied by several authors before. In the present study, we have estimated the evolution of the internal thermodynamical state of CME on 2010 April 3 and 2008 December 12 using the flux rope internal state (FRIS) model during their heliospheric propagation. We focus on deriving the evolution of the polytropic index, heating/cooling rate, Lorentz, and thermal pressure force inside the CME. We used the graduated cylindrical shell (GCS) model to recover the 3-D geometry from the projected images of the CME. We have estimated the kinematic parameters by combining the GCS model with the drag-based model(DBM) for CME propagation near the sun to 1 AU. We have outlined the limitations of our study. Furthermore, we have discussed the possible causes of the discrepancies between the model-derived results and in-situ observations. |
