A method of estimating the lower bound of coronal magnetic field strength in the neighborhood of an ejecting plasmoid is presented. Based on the assumption that the plasma ejecta is within a magnetic island, an analytical expression for the force acting on the ejecta is derived. The method is applied to a limb coronal mass ejection event, and a lower bound of the magnetic field strength just below the CME core is estimated. The method is expected to provide useful information on the strength of reconnecting magnetic field if applied to X-ray plasma ejecta.

• Minhwan Jang(Department of Astronomy and Space Science, Kyung Hee University)
• G. S. Choe(School of Space Research, Kyung Hee University) Corresponding Author
• K.-S. Lee(Department of Astronomy and Space Science, Kyung Hee University)
• Y.-J. Moon(School of Space Research, Kyung Hee University)
• Kap-Sung Kim(School of Space Research, Kyung Hee University)