Charge States and FIP Bias of the Solar Wind from Coronal Holes, Active Regions, and Quiet Sun [SSA]

http://arxiv.org/abs/1701.07610


Connecting in-situ measured solar-wind plasma properties with typical regions on the Sun can provide an effective constraint and test to various solar wind models. We examine the statistical characteristics of the solar wind with an origin in { different types of source regions}. We find that the speed distribution of coronal hole (CH) wind is bimodal with the slow wind peaking at $\sim$400 \velunit\ and a fast at $\sim$600 \velunit. An anti-correlation between the solar wind speeds and the \oql\ ion ratio remains valid in all three types of solar wind as well during the three studied solar cycle activity phases, i.e. solar maximum, decline and minimum. The \feo\ range and its average values all decrease with the increasing solar wind speed in different types of solar wind. The \feo\ range (0.06–0.40, FIP bias range 1–7) for AR wind is wider than for CH wind (0.06–0.20, FIP bias range 1–3) while the minimum value of \feo\ ($\sim$ 0.06) does not change with the variation of speed, and it is similar for all source regions. The two-peak distribution of CH wind and the anti-correlation between the speed and \oql\ in all three types of solar wind can be explained qualitatively by both the wave-turbulence-driven (WTD) and reconnection-loop-opening (RLO) models, whereas the distribution features of \feo\ in different source regions of solar wind can be explained more reasonably by the RLO models.

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H. Fu, M. Madjarska, B. Li, et. al.
Fri, 27 Jan 17
28/54

Comments: accepted for publication in ApJ, 11 pages, 4 figures