Browsing by Author "Esser, Ruth"

Now showing items 1-5 of 5

    • EFFECT OF COULOMB COLLISIONS ON THE GRAVITATIONAL SETTLING OF LOW AND HIGH FIRST IONIZATION POTENTIAL ELEMENTS 

      Bø, Iselin M Thomassen; Esser, Ruth; Lie-Svendsen, Øystein (2013)
      We model the effect of gravitational settling in the upper chromosphere on O, Fe, Si, and Ne, studying whether Coulomb collisions between ionized low First Ionization Potential (FIP) elements and protons is sufficient to ...

    • ELEMENTAL ABUNDANCES IN THE FAST SOLAR WIND EMANATING FROM CHROMOSPHERIC FUNNELS 

      Pucci, Stefano; Lie-Svendsen, Øystein; Esser, Ruth (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 ...

    • MODELING IRON ABUNDANCE ENHANCEMENTS IN THE SLOW SOLAR WIND 

      Byhring, Hanne Sigrun; Cranmer, S.R.; Lie-Svendsen, Øystein; Habbal, S. Rifai; Esser, Ruth (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 ...

    • O and Ne in an H-He Fast Solar Wind 

      Byhring, Hanne Sigrun; Esser, Ruth; Lie-Svendsen, Øystein (2011)
      We have studied the abundances and ion fractions of O and Ne in an H-He fast solar wind with emphasis on gravitational settling in the chromosphere and corona. We use a time-dependent numerical model that spans the mid- ...

    • Solar Wind from Coronal Funnels and Transition Region Lyalpha 

      Esser, Ruth; Lie-Svendsen, Øystein; Janse, Åse Marit; Killie, Mari Anne (2005)
      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 ...