HR: 1330h
AN: SH13A-06    [Abstracts]
TI: The MHD simulation on the coronal plasma in radially shrinking open magnetic flux tubes
AU: * Hayashi, K
EM: keiji@quake.stanford.edu
AF: Stanford University, W.W.Hansen Experimental Physics Lab. 445 Via Palou, Stanford, CA 94305 United States
AU: Zhao, X
EM: zhao@quake.stanford.edu
AF: Stanford University, W.W.Hansen Experimental Physics Lab. 445 Via Palou, Stanford, CA 94305 United States
AU: Poduval, B
EM: bala@quake.stanford.edu
AF: Stanford University, W.W.Hansen Experimental Physics Lab. 445 Via Palou, Stanford, CA 94305 United States
AB: Open field regions in the corona, or coronal holes, have been believed to be rapidly expanding with their flux tube expansion factors, FTEs, greater than 1. We present the MHD simulation results of three-dimensional solar corona, focusing on the opend field regions with FTEs less than 1. Most of such radially shrinking magnetic flux tubes are found to be rooted on the weak open field region sandwiched between two strong open field regions with FTEs greater than 1 and with same magnetic polarity as the weak region. The flow speeds at the shrinking magnetic flux tubes obtained with our MHD simulation are less dependent on FTEs, while the inverse relationship between the flow speed and FTE is obtained at the usual expanding magnetic flux tubes. This finding increases the complex in using the FTE to predict the solar wind speed, and may be used to better understand the coronal plasma expansion.
DE: 2164 Solar wind plasma
DE: 2169 Sources of the solar wind
DE: 7509 Corona
DE: 7511 Coronal holes
SC: SPA-Solar and Heliospheric Physics [SH]
MN: 2005 Joint Assembly