Formation and Expulsion of Large Scale Flux Ropes in Major Solar Eruptions by Reconnection Among Smaller Scale Flux Tubes <p> HR: <span class="hr"> 14:45h<br></span> AN: <span class="an"> SP43C-05 <a href="../absbook/sm05_SP43C.html">[Abstracts]</a><br></span> TI: <span class="ti"> Formation and Expulsion of Large Scale Flux Ropes in Major Solar Eruptions by Reconnection Among Smaller Scale Flux Tubes <br></span> AU: <span class="au"> * Choe, G S<br></span> EM: <span class="em"> gchoe@pppl.gov<br></span> AF: <span class="af"> Princeton Plasma Physics Laboratory, P. O. Box 451, Princeton, NJ 08543 United States <br></span> AU: <span class="au"> Cheng, C Z<br></span> EM: <span class="em"> fcheng@pppl.gov<br></span> AF: <span class="af"> Princeton Plasma Physics Laboratory, P. O. Box 451, Princeton, NJ 08543 United States <br></span> AU: <span class="au"> Lee, J <br></span> EM: <span class="em"> leej@njit.edu<br></span> AF: <span class="af"> New Jersey Institute of Technology, 323 Martin Luther King Blvd, Newark, NJ 07102-1982 United States <br></span> AB: <span class="ab"> Observations of solar eruptions often show a sudden appearance and expulsion of a large scale loop structure following a brightening of smaller scale loops. Also, the distance between the legs of a CME loop is generally much larger than the separation distance between H<sub>α</sub> flare ribbons or between hard X-ray emission features. To explain this, Kopp-Pneuman type standard solar eruption models would require a footpoint shearing over a huge distance, which, however, is not observationally confirmed. To address this problem, we perform a 3D MHD simulation study on evolution of an idealized active region composed of several magnetic flux tubes whose field connectivities are individually discrete. Footpoint twisting motions are applied within individual flux tubes so that the longitudinal magnetogram does not change at all whereas magnetic shear near the polarity inversion line rapidly increases as could be seen in a vector magnetogram. Magnetic reconnection between the flux tubes results in a new field line connection, in which the distance between the footpoints is larger than the original one. After a certain amount of magnetic flux is reconnected, a helical flux rope of a visibly larger scale is created and it is expelled out of the active region leaving the underneath field lines open. An observational example corresponding to this simulation will also be presented. <br></span> DE: <span class="de"> 7513 Coronal mass ejections<br></span> DE: <span class="de"> 7519 Flares<br></span> DE: <span class="de"> 7524 Magnetic fields<br></span> DE: <span class="de"> 7835 Magnetic reconnection<br></span> DE: <span class="de"> 7843 Numerical simulation studies<br></span> SC: <span class="sc"> Solar Physics Division - AAS [SP]<br></span> MN: <span class="mn"> 2005 Joint Assembly<br></span></p></body></html>