1. Flare Dynamics in the Lower Solar Atmosphere H. S. Hudson Space Sciences Laboratory, University of California, Berkeley, USA Astronomy & Astrophysics Group, Glasgow Telluride, March 30, 2011

2. Outline Telluride, March 30, 2011 1)Some background on the lower atmosphere 2) Some background on flares 3)The sunquake and momentum balance 4)Merits of Orbiter

3. Outline Telluride, March 30, 2011 1)Some background on the lower atmosphere 2) Some background on flares (Fletcher talk) 3)The sunquake and momentum balance 4)Merits of Orbiter

4. Motivation: the chromosphere Telluride, March 30, 2011 Wedemeyer-Bohm et al. (2008) http://sprg.ssl.berkeley.edu/~stephchow/cartoons/ Note vertical scale, 2 Mm

5. Electrodynamic mapping of the solar interior to the corona Telluride, March 30, 2011 Collisionality drops precipitously Hydrogen ionizes Plasma beta plummets Structurally important radiation escapes Vertical currents threading the photosphere carry the non-potential energy Recall debate between Parker and Melrose in ApJ (1996)

6. Comment: MHD vs Plasma Physics Telluride, March 30, 2011 Paper 1 (the source of the cartoon) describes the rough structure of the solar atmosphere without much plasma physics (2008) Paper 2 (and earlier papers) struggle to understand the microphysics Large-scale problems in the solar atmosphere (e.g. chromospheric heating) require microphysics insights (e.g., T e  T i ) Paper 1 Paper 2

7. Sunquake SOL2011-02-15 Telluride, March 30, 2011 Kosovichev, 2011

8. Significance of Sunquakes Telluride, March 30, 2011 The sunquake acoustic waves contain.01-.1% of the flare energy They are the only known feedback between the corona and the interior There are at least four worthy ideas for exciting sunquakes (shock, backwarming, Lorentz force,  0 ) Momentum conservation implicates CMEs

9. Significance of Sunquakes Telluride, March 30, 2011 The sunquake acoustic waves contain.01-.1% of the flare energy They are the only known feedback between the corona and the interior There are at least four worthy ideas for exciting sunquakes (shock, backwarming, Lorentz force,  0 or other high-energy particles) Momentum conservation implicates CMEs Flare photospheric and chromospheric emissions contain the solution to the sunquake mechanism

10. Merits of Orbiter Telluride, March 30, 2011 The disk-sensing instruments will give the first new vantage on the solar atmosphere They will revolutionize the classical astronomical tool of limb-darkening studies We can thus study the atmo- sphere in 3D for the first time Classical (VAL-C) thickness of chromosphere 2 Mm and 1D, a poor match to the structure Note vertical scale, 2 Mm

11. Discoveries to be made Telluride, March 30, 2011 What is the mechanism of white-light flare continuum (energetically, the most important flare component)? How are flare seismic waves excited? What is the physical nature of the rough structure? Woods et al. 2005

12. Conclusions Telluride, March 30, 2011 Orbiter will revolutionize solar astronomy via its remote sensing of the disk from a new vantage It is easy to identify fundamentally important flare problems for which this capability will be decisive The juxtaposition of in-situ and remote sensing helps to bring plasma-physics concepts to our attention in the solar atmosphere

13. Extra Slides Telluride, March 30, 2011

14. EVE 304A for SOL2010-06-12 Telluride, March 30, 2011 RHESSI 100 keV EVE 30.4 nm

15. Extrapolation of photospheric field Telluride, March 30, 2011 De Rosa et al. 2009 No chromosphere => Erroneous results?

16. Motivation: the flares Telluride, March 30, 2011 Fletcher-Hudson 2008F What is the tensor conductivity? How is momentum conserved? How are the particles accelerated?

17. Modeling the chromosphere Telluride, March 30, 2011 Semi-empirical 1D models (VAL-C type) 1D radiation hydro models (e.g. Fisher, McClymont) of flares 3D (MHD) models (Asplund abundances results; Abbett) Plasma physics; see pages at http://sprg.ssl.berkeley.edu/~stephc how/plasma/webpage/plasma.html Vernazza et al. 1981 (VAL-C)