1. Aug 16, 2004 Coronal loops formed by separator reconnection: The birth & life of AR9574 Dana Longcope Montana State University

2. Aug 16, 2004 Collaborators: Jonathan CirtainJonathan Cirtain Dave McKenzieDave McKenzie Jason ScottJason Scott Support: NASA grant NAG5-10489 NASA grant NAG5-10489 Isaac Newton Institute, Cambridge Isaac Newton Institute, Cambridge MSU

3. Aug 16, 2004 Outline What happened in Aug. 2001What happened in Aug. 2001 Cataloging interconnectionsCataloging interconnections Making a magnetic modelMaking a magnetic model Interp’ing data w.r.t. the modelInterp’ing data w.r.t. the model What does it tell us about reconnectionWhat does it tell us about reconnection

4. Aug 16, 2004 Case study: AR 9574 SoHO MDI White light Line-of-sight B 2001 Aug 11, 11:15 UT

5. Aug 16, 2004 Case study: AR 9574 SoHO MDI White light Line-of-sight B AR9570 AR9570 2001 Aug 11, 11:15 UT

6. Aug 16, 2004 Case study: AR 9574 SoHO MDI White light Line-of-sight B AR9570 AR9570 AR9574 AR9574 2001 Aug 11, 11:15 UT

7. Aug 16, 2004 Case study: AR 9574 PHOTOSPHERE 2001-08-10 12:51 UT AR9570 AR9574 movie

8. Aug 16, 2004 Case study: AR 9574 PHOTOSPHERE CORONA TRACE 171A (10 6 K Plasma) 2001-08-10 12:51 UT movie

9. Aug 16, 2004 The emergence process whiteblack white black 2001-08-10 12:51 UT 2001-08-11 17:39 UT

10. Aug 16, 2004 Timeline of emergence 00:0012:0000:0012:00 Aug 10, 2001 Aug 11, 2001 00:00 PHOTOSPHERE CORONA 7:34

11. Aug 16, 2004 Why this is reconnection Emerged flux Reconnected flux Old flux

12. Aug 16, 2004 Interconnecting loops: A catalog Synthetic slit TRACE 171 images: 5139 images @ 28 sec 7:00 Aug10 – 23:59 Aug11 BG subtracted

13. Aug 16, 2004 Stack slit pixels… Time after 00:00 Aug10 Position @ 11:00 Aug10 11:00

14. Aug 16, 2004 Loops are bright features

15. Aug 16, 2004 Lots of loops:~9:00  14:00 Gen’lbright’g 1 st loop: 12:36

16. Aug 16, 2004 Finding the loops Identify peaks Identify peaks in slit-intensity in slit-intensity loop = fw @ hm loop = fw @ hm

17. Aug 16, 2004 Finding the loops Identify peaks Identify peaks in slit-intensity in slit-intensity loop = fw @ hm loop = fw @ hm 25 2624 22 23

18. Aug 16, 2004 Finding the loops Show peaks vs. time Loop = row of peaks

19. Aug 16, 2004 Finding the loops Verify spatial correspond- ence w/ intercon’ing loops

20. Aug 16, 2004 Interconnecting loops: A catalog total loops 43 loops identified 1 st loop: (probably)interconnects loop:definitelyinterconnects loop flurry ~9:00 171A intensity

21. Aug 16, 2004 Interconnecting loops: A catalog properties of all 43 loops density lower bound

22. Aug 16, 2004 Magnetic Model Identify distinct regions with |B z | > 45 G SoHO MDI movie

23. Aug 16, 2004 Magnetic evolution

24. Aug 16, 2004

25. Coronal Field State of least energy: Potential Field

26. Aug 16, 2004 Coronal Field Includes connections AR9574 to AR9570 (P051  N01) …all under separatrix surface

27. Aug 16, 2004 Separatrices enclose loops

28. Aug 16, 2004 Coronal Field Inter-connecting lines enclosed by separator

29. Aug 16, 2004 Coronal Field Inter-connecting flux: Potential field: Increasing Increasing interconnection Increasing AR9574 P051

30. Aug 16, 2004 Flux in 171A loops Assumptions 1.Each loop is a field-line bundle (flux tube) 2.Loops/flux tubes : x-section 3.Loop track flux tube for entire life 4.No flux tube re-appears in 171 A

31. Aug 16, 2004 Flux in 171 A loops 1. Each loop is a field-line bundle (flux tube)

32. Aug 16, 2004 Flux in 171 A loops Cummulative loop areas loops Flux if B 0 = 30 G Y Flux in pot’l model

33. Aug 16, 2004 Reconnection observed Y Flux in pot’l model 24 hour delay Incompletereconnection Burst of reconnection 10 16 Mx/sec = 100 MV

34. Aug 16, 2004 The story of the loops density lower bounds radiative cooling time (upper bound on life) life time  heating RTV equilibria

35. Aug 16, 2004 The story of the loops Yohkoh SXT TRACE 171 A 950,000 K ~3,000,000 K movie Loops are hot (~3MK) after reconnection… Gradually cool into TRACE pass-band (All of them?)

36. Aug 16, 2004 There were no flares Reconnection burst

37. Aug 16, 2004 Model of energy storage Unconstrained minimum: Flux Y=Y (v) linking poles 0 W pot W

38. Aug 16, 2004 Model of energy storage Constrain Flux Y & minimize energy… 0 W fce W pot W DWDWDWDW Flux Constrained Equilibrium (Longcope 2002)

39. Aug 16, 2004 Model of energy storage Lowest Energy w/ fixed Y: Flux Constrained Equilibrium (Longcope 2002) Current-free Current-free except … except …

40. Aug 16, 2004 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:

41. Aug 16, 2004 Steady Reconnection? = 4 months Sweet-Parker:

42. Aug 16, 2004 Comparison of scales Sweet-Parker: c/ w pi riririri

43. Aug 16, 2004 Role(s) of Current Sheet Site of localized reconnection 10 18 Mx of newly reconnected flux (1% of DY )

44. Aug 16, 2004 Role(s) of Current Sheet 10 18 Mx of newly reconnected flux (1% of DY ) Releases D E ~ I Dy ~ 10 28 ergs

45. Aug 16, 2004 Role(s) of Current Sheets 0 W fce W pot W DWDWDWDW Energy storage: W accumulates for 24 hrs. prior to reconn’ burst Rapidly released via local process

46. Aug 16, 2004 Summary 1.AR 9574: Example of reconnection between new & old active regions 2.Reconnection occurs in brief (6 hour) burst after delay of ~24 hours 3.Produces dozens of ~10 18 Mx loops 4.Observed flux accounts for 10% - 30% of maximum allowed (partial reconn.)