Coronal Holes and Solar Wind Acceleration : Proceeding of the SOHO-7 Workshop, held at Asticou Inn in Northeast Harbor, Maine, U.S.A., from 28 September-1 October, 1998

The SOHO-7 Workshop was held from 28 September through 1 October 1998 at the Asticou Inn in Northeast Harbor, Maine. The primary topic of this Workshop was the impact of SOHO observations on our understanding of the nature and evolution of coronal holes and the acceleration and composition of the solar wind. The presentations and discussions occasionally went beyond this topic to include the impact of the reported research on other solar structures and the heliosphere. SOHO (the Solar and Heliospheric Observatory), a project of international cooperation between ESA and NASA, was launched in December 1995 and began its science operations during the first few months of 1996. To many solar and space physicists, it was a great advantage that SOHO began itscomprehensive look at the Sun during the 1996 solar minimum. The qualitatively simple two-phase corona, with polar coronal holes expanding into the high-speed solar wind, and a steady equatorial streamer belt related somehow to the stochastic slow-speed solar wind, allowed various SOHO diagnostics to be initiated with a reasonably well­ understoodcircumsolar geometry. The analysis of subsequentSOHO measurements made during the rising phase of solar cycle 23 will continue to benefit from what has been learned from the first two years of data. Front Matter....Pages i-xi Solar Wind Models from the Sun to 1 AU: Constraints by in Situ and Remote Sensing Measurements....Pages 1-24 Acceleration of the High Speed Solar Wind in Coronal Holes....Pages 25-41 Coronal Hole Boundaries and their Interactions with Adjacent Regions....Pages 43-54 Composition Variations in the Solar Corona and Solar Wind....Pages 55-66 Working Group 1 Report: Solar Wind Models from the Sun to 1 AU: Constraints By “In Situ” and Remote Sensing Measurements....Pages 67-77 Working Group 2 Report: Energy Input, Heating, and Solar Wind Acceleration in Coronal Holes....Pages 79-92 Working Group 3 Report: Coronal Hole Boundaries and Interactions with Adjacent Regions....Pages 93-104 Working Group 4 Report: Composition and Elemental Abundance Variations in the Solar Atmosphere and Solar Wind....Pages 105-121 Soho after 30 Months: A Personal View....Pages 123-128 Swan Observations of the Solar Wind Latitude Distribution and Its Evolution Since Launch....Pages 129-132 On the Stability of Siphon Flows Confined in Coronal Loops....Pages 133-136 Fast and Slow Flows in the Solar Wind near the Ecliptic at 1 AU?....Pages 137-140 EUV and Radio Observations of an Equatorial Coronal Hole....Pages 141-144 The Solar Magnetic Field as a Coronal Hole Extension Forms: Effects of Magnetic Helicity and Boundary Conditions....Pages 145-148 Spectroscopic Constraints on Models of Ion-Cyclotron Resonance Heating in the Polar Solar Corona....Pages 149-152 Coronal Heating: A Comparison of Ion-Cyclotron and Gravity Damping Models....Pages 153-156 Compressible Aspects of Slow Solar Wind Formation....Pages 157-160 Statistical Analysis of EUV and UV Lines Inside and Outside of Solar Coronal Holes....Pages 161-164 Two-Fluid 2.5D MHD Simulations of the Fast Solar Wind in Coronal Holes and the Relation to UVCS Observations....Pages 165-168 Characterization of Solar Coronal Holes and Plumes Using Spectroscopic Diagnostic Techniques Applied to SOHO/CDS Observations....Pages 169-172 Comparison of Polar and Equatorial Coronal Holes Observed by UVCS/SOHO: Geometry and Physical Properties....Pages 173-176 Variation of Polar Coronal Hole Profiles with Solar Cycle....Pages 177-180 Large-Scale Coronal Heating, Clustering of Coronal Bright Points, and Concentration of Magnetic Flux....Pages 181-184 EUV Observations Above Polar Coronal Holes....Pages 185-188 UVCS/SOHO Ion Kinetics in Coronal Streamers....Pages 189-192 A Parallel Adaptive 3D MHD Scheme for Modeling Coronal and Solar Wind Plasma Flows....Pages 193-198 Semi-Empirical MHD Model of the Solar Wind and Its Comparison with Ulysses....Pages 199-206 Plasma Properties in Coronal Funnels....Pages 207-210 The Rotation of The Fe XIV Solar Corona During the Recent Solar Activity Minimum....Pages 211-214 A CDS Observation of the Relationship Between a Coronal Hole and Chromospheric Structure....Pages 215-218 Study of Dynamical Properties of Coronal Structures in the Polar Regions....Pages 219-222 Numerical Simulations of Stellar Winds....Pages 223-226 On the Electron Temperature and Coronal Heating in the Fast Solar Wind Constrained by In-Situ Observations....Pages 227-231 UVCS/SOHO Observations of Spectral Line Profiles in Polar Coronal Holes....Pages 233-236 The Highest Solar Wind Velocity in a Polar Region Estimated from IPS Tomography Analysis....Pages 237-239 Observation of Transition Region Fine Structures with SOHO/SUMER....Pages 241-244 Loop Models from SOHO Observations....Pages 245-248 Search for Signatures of a Coronal Hole in Transition Region Lines near Disk Center....Pages 249-252 A 16-Moment Fast Solar Wind Model....Pages 253-256 Hybrid Simulations of Wave Propagation and Ion Cyclotron Heating in the Expanding Solar Wind....Pages 257-260 Magneto-Gravity Waves Trapped in the Lower Solar Corona....Pages 261-264 Ly-α Observation of a Coronal Streamer with UVCS/SOHO....Pages 265-268 Fluctuations, Dissipation and Heating in the Corona....Pages 269-275 Properties of Coronal Hole/Streamer Boundaries and Adjacent Regions as Observed by Spartan 201....Pages 277-281 Coronal Heating by Magnetic Explosions....Pages 283-286 SOHO Observations of Density Fluctuations in Coronal Holes....Pages 287-290 Outflow Velocities at the Base of a Polar Coronal Hole During the 1998 Total Eclipse....Pages 291-294 Velocity Shear Induced Phenomena in Solar Atmosphere....Pages 295-298 Signatures of Coronal Hole Spectra Between 660 Å and 1460 Å Measured with SUMER on SOHO....Pages 299-302 Acceleration Profile of the Slow Solar Wind as Inferred from Gradual Mass Ejections Observed by LASCO....Pages 303-306 MICA: The Mirror Coronagraph for Argentina....Pages 307-310 Constraints on Coronal Outflow Velocities Derived from UVCS Doppler Dimming Measurements and In-Situ Charge State Data....Pages 311-314 Coronal Hole Properties Observed with SUMER....Pages 315-318 Ulysses-UVCS Coordinated Observations....Pages 319-322 Streamer Evaporation....Pages 323-326 UVCS/SOHO Observations of H I Lyman Alpha Line Profiles in Coronal Holes at Heliocentric Heights above 3.0 R ☉ ....Pages 327-330 Ion Temperatures as Observed in a Solar Coronal Hole....Pages 331-334 UVCS Observations and Modeling of Streamers....Pages 335-338 Alfvén Wave Generation in Photospheric Vortex Filaments, Macrospicules, and “Solar Tornadoes”....Pages 339-343 Comparing Quiet Sun and Coronal Hole Regions with CDS/SOHO....Pages 345-348 On the Lyman α and O VI Line Profiles in Streamers and Coronal Holes....Pages 349-352 The Transition Between Fast and Slow Solar Wind from Composition Data....Pages 353-356 The Proceedings of the SOHO-7 Workshop provide an overview of how observations with the Solar and Heliospheric Observatory (SOHO) have led to greater understanding about the nature and evolution of coronal holes and the acceleration of the solar wind. Coronal holes are regions of low density plasma on the Sun that have magnetic fields that expand freely into interplanetary space, and SOHO has allowed solar physicists to investigate the detailed physical processes responsible for maintaining this complex state. The SOHO-7 Workshop Proceedings focus on four topics: (1) constraints by interplanetary and remote-sensing measurements on solar wind models, (2) energy input, heating, and wind acceleration in coronal holes, (3) coronal hole boundaries and adjacent regions, and (4) composition and elemental abundance variations. This book will be of use to the entire solar community by providing scientists with a concise summary of the progress SOHO has made in this field, and young researchers can use it to learn about the most relevant topics in this rapidly evolving discipline.