• Elemental Abundances in the Fast Solar Wind Emanating from Chromospheric Funnels 

      Pucci, Stefano; Lie-Svendsen, Øystein; Esser, Ruth (Journal article; Tidsskriftartikkel; Peer reviewed, 2010)
      We carry out a model study to determine whether a funnel-type flow geometry in the solar wind source region leads to sufficiently fast hydrogen flow to offset heavy element gravitational settling and can thus explain why solar wind abundances are not much smaller than photospheric abundances. We find that high first ionization potential (FIP) elements are more susceptible to gravitational settling ...
    • Modeling iron abundance anhancements in the slow solar wind. 

      Byhring, Hanne Sigrun; Cranmer, S.R.; Lie-Svendsen, Øystein; Habbal, S. Rifai; Esser, Ruth (Journal article; Tidsskriftartikkel; Peer reviewed, 2011)
      We have studied the behavior of Fe ions in the slow solar wind, using a fluid model extending from the chromosphere to 1 AU. Emphasis is on elemental "pileup" in the corona, i.e., a region where the Fe density increases and has a local maximum. We study the behavior of individual Fe ions relative to each other in the pileup region, where Fe(+10) and Fe(+12) have been used as examples. We find that ...
    • Solar Wind from Coronal Funnels and Transition Region Lyalpha 

      Esser, Ruth; Lie-Svendsen, Øystein; Janse, Åse Marit; Killie, Mari Anne (Journal article; Tidsskriftartikkel; Peer reviewed, 2005-08-10)
      Using a newly developed gyrotropic solar wind model that extends continuously from the mid-chromosphere to 1 AU and that accounts for radiative losses in the transition region, we have studied the difference between the fast solar wind emanating from a funnel geometry and a ``traditional'' rapidly expanding wind. The main aim is to determine whether or not observations of the Lyalpha intensity in ...