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Heating from Reconnection Quantified

Heating from Reconnection Quantified. Dana Longcope Montana State University. Acknowledgments:. Erik Aver Jonathan Cirtain Charles Kankelborg Dave McKenzie Jason Scott Alexei Pevtsov Robert Close Clare Parnell Eric Priest NASA grant NAG5-10489 NSF grant ATM 97227. MSU. NSO Sac Peak.

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Heating from Reconnection Quantified

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  1. Heating from ReconnectionQuantified Dana LongcopeMontana State University

  2. Acknowledgments: • Erik Aver • Jonathan Cirtain • Charles Kankelborg • Dave McKenzie • Jason Scott • Alexei Pevtsov • Robert Close • Clare Parnell • Eric Priest • NASA grant NAG5-10489 • NSF grant ATM 97227 MSU NSO Sac Peak St. Andrews

  3. Reconnection Heating: Theory • Parker 1972, Parker1983: “Topological dissipation” • Tucker 1973, Levine 1974 Dissipation @ current sheets • Heyvaerts & Priest 1984 Taylor relax’n after QS evol’n • van Ballegooijen 1985 Dissipation of turbulent structure • Parker 1988, Cargill 1993, 1994, … Nanoflares • Longcope 1996, Aly & Amari 1997 QS Formation + rapid elimination of current sheets (Parker 1972) =reconnection?

  4. Heating from Reconnection Heating: P [ ergs/sec ] Reconnection magnetic dissipation Prx[ ergs/sec ] P = Prx [Begging the question?]

  5. Heating from Reconnection Heating: P [ ergs/sec ] Reconnection flux transfer F[ Mx/sec ] Reconnection heating  P = CF m m>0

  6. Reconnection Heating P = CF m • Quasi-static models: tD << tev Heyvaerts & Priest 1984 Longcope 1996 Aly & Amari 1997 … P ~ v P = IqrxF m = 1 Units of constant: Amps

  7. Reconnection Heating P = CF m 2. Resistive dissipation: Parker 1983, 1988 van Ballegooijen 1985 … tD ~ tev P ~ v2 P =(F)2/ R m = 2 Units of constant: Mhos

  8. Quantifying Heating Pevtsov et al. 2003 ARs XBPs

  9. Quantifying Reconnection • What is F? • What is F? • Which field lines change? • Where does the change occur? Average Heating  General setting: assume avg. fieldline is recycled once in time trcyc

  10. Quantifying Reconnection Pevtsov et al. 2003 ARs XBPs

  11. Whither Withbroe & Noyes? Quiet Sun: <|Bz|> ~ 10 Mx/cm2 (Lites 2002)  Fx ~2 x 104ergs/sec/cm2 (Pevtsov et al. 2003) F ~ Fx /c=3 x 105ergs/sec/cm2 (Withbroe & Noyes 1977) c ~ 0.1

  12. Specific Case: AR 9574 Longcope et al. 2004 PHOTOSPHERE 2001 Aug 11, 1:35 CORONA • Emerging AR • Interconnections • How much • reconnection? movie TRACE 171A (106 K Plasma)

  13. P-spheric flux sources emergence begins

  14. Coronal Model Interconnecting flux separator

  15. Finding all the loops Peaks in a “slit”

  16. Separatrices enclose loops

  17. Reconnection observed Y Flux in pot’l model (Longcope et al. 2004) 24 hour delay Burst of reconnection 1016 Mx/sec = 100 MV

  18. Energy release I~ 3 x 1010 A Transfer flux DF Liberate energy DW DW ~ DFIqrx Dissipation? (NO)

  19. Quiet Sun Case: XBP1 TRACE & SOI/MDI observations 6/17/98 (Kankelborg & Longcope 1999)

  20. Quantifying Reconnection • Poles • Converging: v = 218 m/sec • Potential field: - bipole - changing  1.6 MegaVolts (on separator)

  21. Surveys of XBPs • Archival SOHO data • EIT + MDI images • Visually ID XBPs in EIT 195A • Extract bipole prop’s from 12 MDI images (@15min) (Longcope et al. 2000, Aver & Longcope 2005)

  22. Surveys of XBPs 149 XBPs vr 15o v d (Aver & Longcope 2005) F+ F=(F++F-)/2 t=d/vr

  23. (Aver & Longcope 2005) P Diverging bipoles: No Corr’n B0=10 G Converging bipoles: P strongly correlates w/ reconn’n rate proxies 1 G P Iqrx=1011 A F/t vrF

  24. Converging vs. Diverging convergence (closing) divergence (opening) time reconnected flux

  25. Coronal recycling time (Close, Parnell, Longcope & Priest 2004) 240 Mm x 240 Mm quiet Sun region • Identify sources • Coronal field from • potential extrap’n 50 MDI m-grams @ 15 min

  26. Coronal recycling time Fa= p-spheric Flux in source a yi = interconn-ecting flux in domain i Flux balance: “All flux goes somewhere” Change over Dt submergence/emergence Coronal reconnection

  27. Coronal recycling time Recycling by emergence or submegence ~ 15 hours (cf. Hagenaar et al. 2003) 3 hours 1.4 hours Recycling by reconnection 2 diff. methods of elimating Si

  28. Summary • Heating of individual structures:P ~F • Suggests Quasi-static reconnection heating P=IqrxFwithIqrx=2 x 105trcyc • Emerging AR (9574): • Reconnection delayed by ~24 hours • F = 260 MV, I=3 x 1010 A • Heating after reconnection • XBPs: F ~1 MV, I~ 109 A • Convergence/divergence dichotemy • trcyc ~2 hours

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