1. Dec. 10, 2004RHESSI/SOHO/TRACE Pre-flare Energy Storage The possible role of equilibrium current sheets Dana Longcope Montana State University Work supported by NASA NAG5-10489 Thanks: Dave McKenzie Jonathan Cirtain Jason Scott

2. Dec. 10, 2004RHESSI/SOHO/TRACE The Photospheric Field distribution of isolated distribution of isolated sources sources evolution over ~ days evolution over ~ days anchors coronal field anchors coronal field 2001-08-10 12:51 UT 2001-08-11 17:39 UT

3. Dec. 10, 2004RHESSI/SOHO/TRACE The Coronal Field P07 P10 N09 N05 N01 P04 Total flux connecting P i  N j : y ij y 41 y 71 coronal connections y 49

4. Dec. 10, 2004RHESSI/SOHO/TRACE The Coronal Field Potential Field: Potential Field: sources

5. Dec. 10, 2004RHESSI/SOHO/TRACE Quantifying Flux All flux connecting P07  N01 All flux connecting P07  N01 enclosed by 2 separatices enclosed by 2 separatices Intersect at separator Intersect at separator separator null

6. Dec. 10, 2004RHESSI/SOHO/TRACE Quantifying Flux close path separator All P07  N01 lines enclosed All P07  N01 lines enclosed All flux connecting P07  N01 All flux connecting P07  N01 enclosed by 2 separatices enclosed by 2 separatices Intersect at separator Intersect at separator

7. Dec. 10, 2004RHESSI/SOHO/TRACE Model of energy storage Unconstrained minimum: Flux y=y (v) linking poles 0 W pot W

8. Dec. 10, 2004RHESSI/SOHO/TRACE Model of energy storage Constrain Flux y & minimize energy… 0 W fce W pot W DWDWDWDW Flux Constrained Equilibrium (Longcope 2002) Potential iff Dy=y-y (v) =0

9. Dec. 10, 2004RHESSI/SOHO/TRACE Model of energy storage Lowest Energy w/ fixed y: Flux Constrained Equilibrium (Longcope 2002) Current-free Current-free except … except …

10. Dec. 10, 2004RHESSI/SOHO/TRACE Model of energy storage Flux Constrained Equilibrium (Longcope 2002) Current-free Current-free except … except … Current Sheet Current Sheet @ separator @ separator I ( Dy ) I ( Dy ) Mag. Energy Mag. Energy in excess of in excess of potential potential D W( Dy ) D W( Dy ) Lowest Energy w/ fixed y:

11. Dec. 10, 2004RHESSI/SOHO/TRACE Role(s) of Current Sheets 0 W fce W pot W DWDWDWDW Energy storage: D W accumulates prior to reconn’ burst Stored globally

12. Dec. 10, 2004RHESSI/SOHO/TRACE Steady Reconnection? = 4 months Sweet-Parker:

13. Dec. 10, 2004RHESSI/SOHO/TRACE Role(s) of Current Sheet Site of localized reconnection 2 X 10 18 Mx of newly reconnected flux (1% of Dy )

14. Dec. 10, 2004RHESSI/SOHO/TRACE Role(s) of Current Sheet 2 X 10 18 Mx of newly reconnected flux (1% of Dy ) Releases D E ~ I Dy ~ 10 31 ergs

15. Dec. 10, 2004RHESSI/SOHO/TRACE Role(s) of Current Sheets 0 W fce W pot W DWDWDWDW Energy storage: D W accumulates prior to reconn’ burst: latency Rapidly released via local field via local E field

16. Dec. 10, 2004RHESSI/SOHO/TRACE Flux emergence AR9574 begins emerging @ 7:34 2001-08-10 AR9570 remains

17. Dec. 10, 2004RHESSI/SOHO/TRACE Stack plot of inter- connectingloops Evidence of reconn’n latency loops

18. Dec. 10, 2004RHESSI/SOHO/TRACE Evidence of reconn’n latency GOES 1-8 A loops EUV loop EUV emergence TRACE 171 A

19. Dec. 10, 2004RHESSI/SOHO/TRACE Evidence of reconn’n latency reconnection latency cooling emergence

20. Dec. 10, 2004RHESSI/SOHO/TRACE Evidence of reconn’n latency y (v) y from potential model from observed loops latency latency ~24 hrs flux transfer 3.5 hrs Dy = 10 21 Mx d y /dt = 10 9 V

21. Dec. 10, 2004RHESSI/SOHO/TRACE Consequence of latency I = 1.3 x 10 11 Amps D W FCE = 1.4 x 10 31 ergs Dy = 10 21 Mx

22. Dec. 10, 2004RHESSI/SOHO/TRACE Consequence of latency GOES 1-8 A GOES 0.5-4 A Radiated power P ~ 5 x 10 26 erg/sec Radiated energy10 31 ergs D W FCE = 10 31