Study On The Relationship Between The Spectral Diagnosis Of The Crowned Feather And The Characteristics Of The Solar Wind And The Source Region

The solar wind is an important medium through which the Sun can im-pact the Earth and influence the near-Earth space environment. Since the solar wind was first measured in 1962, the origin of the solar winds, the properties of their source regions, and the way how they connect with their source regions are important both as a fundamental issue in solar physics and from the space environment perspective.In the past decades, various efforts have been made to study the source re-gions of the solar wind. Since a long time ago, coronal holes have been believed to be the main source region of the fast solar wind. However, the plasma properties prevailing in coronal holes have not yet fully understood because coronal holes are highly dynamic and structured. For example, plumes are most conspicuous structures observed in coronal holes. Therefore, the contribution of plumes to the solar wind become an important issue. On the other hand, the origin of the slow solar wind is unclear in details. Statistical studies with both in situ observations of solar winds and remote sensing observations of their source regions are needed since the properties of the solar wind are closely related to the source regions. In this thesis, the properties, especially outflow velocities of plumes will be an-alyzed with the spectroscopic observations of EIS/Hinode, and the contribution of plumes to the solar wind will be also evaluated. Furthermore, we identify the coronal sources of the solar winds sampled by the ACE spacecraft during 1999-2008, and examine the in situ solar wind properties as a function of wind sources.The contribution of plumes to the solar wind has been subject to hot debate in the past decades. Evidently, such a debate requires measurements of the electron density and flow velocity in plumes. In this thesis, we measure the outflow velocity at coronal heights in several on-disk long-duration plumes, which are located in coronal holes and show significant blue shifts throughout the entire observational period. Furthermore, we provide an outflow velocity profile along the plumes, finding that the velocity corrected for the line-of-sight effect can reach 10 kms-1 at 1.02 R☉,15 kms-1 at 1.03 R☉, and 25 kms-1 at 1.05 R☉ The clear signature of steady acceleration, combined with the fact that there is no significant blue shift at the base of plumes, provides an important constraint on plume models. At the height of 1.03 R☉, EIS also deduced a density of 1.3×108 cm"3, resulting in a proton flux of about 4.2×109 cm-2s-1 scaled to 1AU, which is an order of magnitude higher than the proton input to a typical solar wind if a radial expansion is assumed. This suggests that, coronal hole plumes may be an important source of the solar wind.We identify the coronal sources of the solar winds sampled by the ACE s-pacecraft during 1999-2008, and examine the in situ solar wind properties as a function of wind sources. The standard two-step mapping technique is adopted to establish the photospheric footpoints of the magnetic flux tubes along which the ACE winds flow. The footpoints are then placed in the context of EIT 284A images, allowing us to categorize the sources into three groups:coronal holes (CHs), active regions (ARs), and the quiet Sun (QS). We find that during the maximum phase, CHs and ARs are equally important contributors to the ACE solar winds, with the contribution from the QS being negligible. During the declining phase, the majority of the ACE winds originate from CHs, whose con-tribution maximizes in 2003. From 2003 onward, the QS contribution increases with decreasing solar activity, and maximizes in the minimum phase when CHs and the QS appear to be the primary suppliers of the ACE winds. With decreas-ing activity, the winds from all sources tend to become cooler, as represented by the increasingly low O7+/O6+ratios. On the other hand, during each activi-ty phase, the AR winds tend to be the slowest and associated with the highest O7+/O6+ratios, and the CH winds correspond to the other extreme, with the QS winds lying in between. Applying the same analysis method to the slow winds only, here defined as the winds with speeds lower than 500 km/s, we find basi-cally the same overall behavior, as far as the contributions of individual groups of sources are concerned. The exception is that, during the minimum phase, the QS may be the important contributor to the slow wind sampled by ACE. The results also suggest that a criterion combining the speed and charge state values may better separate winds from different sources than individual parameters.