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Session 1 - Chromosphere, Corona, Flares.
Display session, Friday, June 27
Ballroom B, Chair: Charles Kankelborg

[1.17] Doppler Shifts and Nonthermal Broadening in the Quiet Solar Transition Region: O VI

H. P. Warren, J. T. Mariska (NRL), K. Wilhelm (MPAe), P. Lemaire (IAS)

Using observations from the Solar Ultraviolet Measurements of Emitted Radiation (SUMER) experiment flown on the Solar and Heliospheric Observatory (SOHO\,) spacecraft, we have measured Doppler wavelength shifts and nonthermal broadening in the 1032 and 1038\,Å\ emission lines of O\,\sc vi and the 1036 and 1037\,Å\ emission lines of C\,\sc ii. Near Sun center the C\,\sc ii lines exhibit an average redshift of 2\pm3\,km s^-1, consistent with earlier observations in this temperature range. The O\,\sc vi emission lines exhibit average Doppler velocities of 5\pm3\,km s^-1 suggesting the presence of redshifted material at 2.9\times10^5\,K. For the O\,\sc vi lines, the average nonthermal component of the observed line width is 34\pm3\,km s^-1. These observations indicate a tendency for brighter regions to have larger average redshifts and line widths than faint features although the relationship is very weak. Preliminary analysis of observations at the limb suggests that the Doppler velocities for O\,\sc vi do not approach zero as would be expected for predominately radial motions.

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