Abundances in the Solar Atmosphere and in the Solar Wind

1. Abundances in the Solar Atmosphere and in the Solar Wind • Tuesday PM and Wednesday AM • EnricoLandi (University of Michigan) • Daniel Wolf Savin (Columbia University)

2. How to collapse 5 hours of talks and discussion into a 15 minute summary • Cleary that’s not possible. • I’ve picked some highlights to illustrate the subjects covered. • Hopefully this will give a flavor of the Session. • Apologies in advance to the speakers for mangling what they presented in the Session.

3. Spectroscopic Determination of Solar Atmosphere Abundances (Peter Young) • Abundances say something about solar physics FIP bias (corona/photosphere) First Ionization Potential (eV)

4. FIP bias measurements in the solar corona show significant variability • Coronal holes • no FIP bias (reasonably solid result) • Quiet Sun • FIP bias = 2 to 4 • Transition region not consistent with corona • Active regions • FIP bias seems to vary with age of structures • Different structures in same AR have different biases • Interpreting these results is hindered by a lack of quantitative theoretical models.

5. Solar Wind Heavy Ions Over Solar Cycle 23: ACE/SWICS Measurements (Sue Lepri) • How much do distribution and fractional contribution from each type of wind changes over solar cycle? • Goal is to study the solar cycle evolution of both the fast and slow solar wind using ecliptic plane in-situ data. • How do plasma parameters, charge state distributions and elemental composition evolve with solar cycle? • Do the fast and slow wind properties evolve in the same way?

6. ACE/SWICS elemental composition measurements over solar cycle 23 • Heavy elements depleted towards solar minimum, with slow wind becoming more depleted than fast. • This is in line with predictions for enhanced Coulomb drag, predicted for lower coronal densities. • FIP bias preserved in slow wind, ordering changes in fast. • Abundances behavior suggests reduced proton flux from corona & less efficient acceleration of heavy ions. • Interpreting these results is hindered by a lack of quantitative theoretical models.

7. Poster presentations of other in-situ studies • Polar and equatorial coronal hole winds at solar minima: ACE & Ulysses observations • P81:Liang Zhang • Correlation of heavy ion dropouts with heliosphericand magnetic structures • P83: Micah Weberg

8. PLENARY: Elemental Fractionation in the Solar Corona and Wind (Martin Laming) • FIP Effect due to action of ponderomotive force in chromosphere acting on ions, not neutrals. • Coronal loop acts as resonant cavity for Alfvénwaves. • Alfvén waves can have either chromospheric or coronal origin. • Waves originating in loop (generally resonant) imply a positive FIP effect as well as He depletion.

9. Ponderomotive model does good job of reproducing FIP effect in slow & fast wind.

10. Variations of Elemental Composition in the Solar Wind and SEPs (KuenKo)

11. Variations of Elemental Composition in the Solar Wind and SEPs (KuenKo) • Abundance variations w/corresponding changes at origin are critical to understand solar wind formation. • Such studies need accurate 3D global coronal magnetic field data. • Spectroscopic data needed for wide range of temperatures and of both low and high FIP elements. • Need also spectroscopic and in-situ data that match in space and in time.

12. Chromospheric abundances from solar flare gamma-ray spectra (Gerry Share)

13. Simulation of S-Web Corridor Dynamics: Implications for Solar Wind (Aleida Young) • What is the S-Web theory for slow solar wind? • Why is it critical for interpreting solar wind observations? • Current efforts to model S-web corridors. • See P083 for more details.

14. SOHO CELIAS MTOF (James Weygand)

15. The DRUTHERS Mission Definitive Results Uncovering the True Heliospheric Environment Rounding the Sun

16. The DRUTHERS Mission The Kamikaze Mission