B: Fast Solar Wind & Plumes,
Craig DeForest ( 8)

Last Updated Fri Dec 5 16:24:42 2008

1: Craig Deforest (deforest@boulder.swri.edu), Southwest Research Institute [B]
[soi] Group Leader
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2: Kelly Korreck (kkorreck@cfa.harvard.edu), CfA [E]
[soi] I am interested in the origins of the solar wind and the effect of the wind at 1AU. I have investigated this currently using Hinode's XRT and EIS along with ACE and SOHO.
[poster] Solar wind particles are accelerated and heated as they propagate from the solar corona to the earth. Using data from XRT and EIS on Hinode, ACE, and SOHO satellites, we follow the plasma characteristics such as density and flow speed from the solar corona to 1AU. The linear relation between x-ray luminosity, magnetic flux and the power of the solar wind at 1AU is exploited. XRT and EIS data are used to compare the initial conditions of these solar wind particles. In order to study the relationship over a solar cycle, due to the lack of X-ray data from the last solar maximum, the SOHO MDI data will be used with the ACE particle data to examine this relationship at solar maximum. This will be used to predict the relationship for the upcoming solar maximum in terms of x-ray luminosity and particle flux at 1AU.
3: Yang Liu (yliu@sun.stanford.edu), HEPL, Stanford University [F]
[soi] I am interested in solar polar field, and would like to show short time evolution of magnetic elements in high latitude observed by MDI and Hinode.
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4: James McLaughlin (james@mcs.st-and.ac.uk), University of St Andrews [B]
[soi] The solar wind is the stream of charged particles emanating from the Sun. Highly inhomogeneous in nature, its outflow extends over the Earth and the limit of its influence defines the outer boundaries of our solar system. A full understanding of the solar wind is critical for predicting geomagnetic storms, ascertaining the Sun's contribution to climate change, forecasting space weather and modelling stellar winds. Coronal holes are well-known sources of the fast solar wind. Solar plumes are regions of density enhancement inside coronal holes, and are observed as bright, ray-like structures. Solar wind models depend heavily on the properties of the source region and, since plumes are ubiquitous to coronal holes, plumes represent a substantial but currently poorly understood contribution. Hence, a detailed knowledge of the nature of solar plumes is essential in order to accurately understand the solar wind. By participating in this working group, I hope to discuss and contribute to answering the following scientific questions: (1) What are the fundamental properties of solar plumes, and what is their link to the fast solar wind? (2) What governs the life cycle of these magnetic structures? (3) What is the energy contribution of (plume-supported) MHD waves to the solar wind, and their role in its acceleration? (4) What is the mechanism driving these MHD wave motions? Is it possible to track this propagation of energy outwards through the solar atmosphere, and into the solar wind?
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5: Mari Paz Miralles (mmiralles@cfa.harvard.edu), Harvard-Smithsonian CfA [F]
[soi] TITLE: The Fast Solar Wind From Large Coronal Holes. AUTHOR: M. P. Miralles.ABSTRACT:We have used spectroscopic observations from the UVCS instrument on SOHO to characterize the physical properties of large coronal holes, from 1996 to the present, in order to investigate the physical processes that lead to the origin of the solar wind. The polar and low-latitude coronal holes studied produced high-speed wind. In April 2008, UVCS joined other space- and ground-based instruments to study the solar wind from a large low-latitude coronal hole during the WHI campaign. In this talk I will present a summary of the derived plasma properties, and discuss how this information is being used to set firm empirical constraints on coronal heating and solar wind acceleration in coronal holes.
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6: Nour-Eddine Raouafi (nraouafi@nso.edu), National Solar Observatory [J]
[soi] PLASMA DYNAMICAL PROPERTIES WITHIN POLAR CORONAL PLUMES Modeling of plasma dynamics within polar coronal plumes is constrained by spectral observations from SOHO/UVCS at the minimum of solar cycle 22-23. Simple Maxwellian velocity distributions for plume and interplume regions are considered. Differences in densities and temperatures are also taken into account. We compute line profiles and total intensities of the H I Ly-alpha and the O VI doublets. The observed profile shapes and intensities are reproduced best by a small solar wind speed at low altitudes in plumes that increases with height to reach ambient interplume values above roughly 3-4 Rsolar, combined with a similar variation of the width of the velocity distribution of the scattering atoms/ions. We also find that plumes very close to the pole give narrow profiles at heights above 2.5 Rsolar, which are not observed. This suggests a tendency for plumes to be located away from the pole. Magnetograms from SOLIS also show uniform density of flux elements up to about 75 degree and a sharp decrease toward the solar pole. This should have important impact on mechanisms of flux transport (i.e., meridional circulation).
[poster] EVOLUTION OF A CORONAL TWISTED FLUX ROPE: FILAMENT FINE STRUCTURE Multi-instrument data sets of NOAA AR10938 on 2007 Jan. 16 (Hinode, STEREO, GOES, ISOON H-alpha, ..) are utilized to study the fine structure and evolution of a highly twisted coronal flux rope. The footpoints of the magnetic threads are closely rooted into pores and plage areas. A C-class flare recorded by GOES at approximately 2:35 UT near one of the rope footpoints (along with a wisp of loop material shown by EUV data) led to the brightening of the flux rope revealing its fine structure with several threads showing high degree of linking. EUV observations by Hinode/EIS of hot lines show a complex structure of coronal loops. The same features were observed about 30 minutes later in X-ray images and about 30 minutes further in EUV images of STEREO/SECCHI/EUVI with much better resolution. H-alpha and EUVI 30.4 nm images revealed the presence of several filament fibrils in the same area. They evolved a few hours later into a denser structure seemingly showing helical structure, which persistently lasted for several days forming a segment of a larger scale filament. This is a direct observational evidence for resolved fine structure of a highly twisted flux tubes leading to the formation of a solar filament.
7: Luca Teriaca (teriaca@mps.mpg.de), Max Planck Institute for Solar System Research [H]
[soi] I am interested on whether plumes are relevant to the acceleration of the fast solar wind. I am investigating this aspect by analysing several datasets obtained with the SUMER spectrometer aboard SOHO to build precise velocity maps and compare them with the radiance pattern that identify the plumes.
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8: Marco Velli (velli@arcetri.astro.it), Jet Propulsion Laboratory, California Institute of Technology [J]
[soi] I am going to contribute with overviews to both of these working groups (a discussion on plumes and a discussion on prominence fine structure).
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Second Choice

Craig Deforest, Linda Hunt, Janet Luhmann, Scott McIntosh, James McLaughlin, Ron Moore, Yi-Ming Wang,