1. 34th Solar Physics Division Meeting, June 2003 Propagating Disturbances in the Lower Solar Corona Meredith J. Wills-Davey Southwest Research Institute Boulder, CO meredith@boulder.swri.edu

2. 34th Solar Physics Division Meeting, June 2003 Summary Analysis of TRACE 13 June 1998 event Wave profiles, flux Evidence for spatial constraints on propagation? Implications of spatial constraints (“wave guides”) Conclusions

3. 34th Solar Physics Division Meeting, June 2003 Wave fronts, trajectories can be automatically tracked, are complex Thick black lines: measured wavefront positions at successive times Thin black lines: interpolated wavefront positions Thin white lines: natural propagation tracks between interpolated fronts Thick white lines: tracks chosen for analysis

4. 34th Solar Physics Division Meeting, June 2003 Cross-sections of density enhancement along tracks show propagation Time Density Enhancement

5. 34th Solar Physics Division Meeting, June 2003 Wave kinetic energy flux does not match expectations for an impulsive driver Time Total wave kinetic energy flux

6. 34th Solar Physics Division Meeting, June 2003 Comparison of TRACE passbands suggests minimum altitude

7. 34th Solar Physics Division Meeting, June 2003 Is there a maximum altitude? Evidence in theories and simulations Original theories Uchida (1968) Meyer (1968) wave guide Meyer  increasing Alfvén speed with altitude creates wave guide Uchida  shallower trajectories trapped in the atmosphere Uchida (1968)

8. 34th Solar Physics Division Meeting, June 2003 Our simple model Turnover in a stratified atmosphere Terradas, Oliver, & Ballester (1999)  finds trapping, analogous to turnover predicted by Meyer Is there a maximum altitude? Evidence in theories and simulations

9. 34th Solar Physics Division Meeting, June 2003 “Wave guiding” is consistent with current observations EIT Waves Uniformity of observations Discrepancy between propagating wave observations in EUV and soft x-ray corona Courtesy of B. Thompson

10. 34th Solar Physics Division Meeting, June 2003 Conclusions Propagations are complex, reflecting complexity of the medium Coronal Seismology? Wave driver is non-impulsive, delivering energy over a period of minutes CME as driver? Propagations not consistent with spherical expansion, appear to be trapped in a coronal “wave guide”

11. 34th Solar Physics Division Meeting, June 2003 A Surprising Find Dispersion of the wave should relate to change in pulse width No measurable width increase Results consist with dispersionless conditions Time Pulse width