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 NAG Thanks: Dave McKenzie Jonathan Cirtain Jason Scott

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 :51 UT :39 UT

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

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

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

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

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

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

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 …

Dec. 10, 2004RHESSI/SOHO/TRACE Model of energy storage Flux Constrained Equilibrium (Longcope 2002) Current-free Current-free except … except … Current Sheet Current 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:

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

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

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

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

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

Dec. 10, 2004RHESSI/SOHO/TRACE Flux emergence AR9574 begins 7: AR9570 remains

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

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

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

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 = Mx d y /dt = 10 9 V

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

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