Aug 16, 2004

Coronal loops formed by Coronal loops formed by separator reconnection:separator reconnection:The birth & life of AR9574The birth & life of AR9574

Dana LongcopeDana LongcopeMontana State UniversityMontana State University

Aug 16, 2004

Collaborators:Collaborators:• Jonathan CirtainJonathan Cirtain• Dave McKenzieDave McKenzie• Jason ScottJason Scott

Support:Support:• NASA grant NAG5-10489NASA grant NAG5-10489• Isaac Newton Institute, CambridgeIsaac Newton Institute, Cambridge

MSUMSU

Aug 16, 2004

OutlineOutline• 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 What does it tell us about

reconnectionreconnection

Aug 16, 2004

Case study: AR 9574Case study: AR 9574

SoHO MDISoHO MDI SoHO MDISoHO MDI

White lightWhite light Line-of-sight BLine-of-sight B

2001 Aug 11, 11:15 UT 2001 Aug 11, 11:15 UT

Aug 16, 2004

Case study: AR 9574Case study: AR 9574

SoHO MDISoHO MDI SoHO MDISoHO MDI

White lightWhite light Line-of-sight BLine-of-sight BAR9570AR9570 AR9570

2001 Aug 11, 11:15 UT 2001 Aug 11, 11:15 UT

Aug 16, 2004

Case study: AR 9574Case study: AR 9574

SoHO MDISoHO MDI SoHO MDISoHO MDI

White lightWhite light Line-of-sight BLine-of-sight BAR9570AR9570 AR9570

AR9574AR9574 AR9574

2001 Aug 11, 11:15 UT 2001 Aug 11, 11:15 UT

Aug 16, 2004

Case study: AR 9574Case study: AR 9574PHOTOSPHERE

2001-08-10 12:51 UT 2001-08-10 12:51 UT

AR9570AR9570

AR9574AR9574

movie

Aug 16, 2004

Case study: AR 9574Case study: AR 9574PHOTOSPHERE

CORONA

TRACE 171A (10TRACE 171A (1066 K Plasma) K Plasma)

2001-08-10 12:51 UT 2001-08-10 12:51 UT

movie

Aug 16, 2004

The emergence processThe emergence process

whitewhite blackblack whitewhite blackblack

2001-08-10 12:51 UT 2001-08-10 12:51 UT 2001-08-11 17:39 UT 2001-08-11 17:39 UT

Aug 16, 2004

Timeline of emergenceTimeline of emergence

00:0000:00 12:0012:00 00:0000:00 12:0012:00Aug 10, 2001Aug 10, 2001 Aug 11, 2001Aug 11, 2001

00:0000:00

PHOTOSPHERE

CORONA

7:347:34

Aug 16, 2004

Why this is reconnectionWhy this is reconnection

Emerged fluxEmerged fluxReconnected fluxReconnected flux

Old fluxOld flux

Aug 16, 2004

Interconnecting loops:Interconnecting loops:A catalogA catalog

Synthetic slitSynthetic slit

TRACE 171 images:TRACE 171 images:5139 images @ 28 sec5139 images @ 28 sec7:00 Aug10 – 23:59 Aug117:00 Aug10 – 23:59 Aug11BG subtractedBG subtracted

Aug 16, 2004

Stack slit Stack slit pixels…pixels…

Time afterTime after00:00 Aug1000:00 Aug10

Position @Position @11:00 Aug1011:00 Aug10

11:00

Aug 16, 2004

Loops are brightfeatures

Aug 16, 2004

Lots ofLots ofloops:loops:~9:00~9:00 14:0014:00

Gen’lGen’lbright’gbright’g

11stst loop: loop:12:3612:36

Aug 16, 2004

Finding the loopsFinding the loops• Identify peaksIdentify peaks in slit-intensityin slit-intensity• loop loop = fw @ hm= fw @ hm

Aug 16, 2004

Finding the loopsFinding the loops• Identify peaksIdentify peaks in slit-intensityin slit-intensity• loop loop = fw @ hm= fw @ hm

25 26 24 22 23

Aug 16, 2004

Finding the loopsFinding the loops

Show peaksShow peaksvs.vs. time time

Loop = rowLoop = rowof peaksof peaks

Aug 16, 2004

Finding the loopsFinding the loops

Verify spatialVerify spatialcorrespond-correspond-ence w/ ence w/ intercon’ingintercon’ingloopsloops

Aug 16, 2004

Interconnecting loops:Interconnecting loops:A catalogA catalog

totaltotalloopsloops

43 loops43 loopsidentifiedidentified

11stst loop: loop:(probably)(probably)

interconnectsinterconnects

loop:loop:definitelydefinitely

interconnectsinterconnectsloop flurry loop flurry

~9:00~9:00

171A

inte

nsity

171A

inte

nsity

Aug 16, 2004

Interconnecting loops:Interconnecting loops:A catalogA catalog

propertiespropertiesof allof all43 loops43 loops

density density lower lower boundbound

Aug 16, 2004

Magnetic ModelMagnetic Model

Identify distinct regions with |BIdentify distinct regions with |Bzz| > 45 G| > 45 G

SoHO MDI movie

Aug 16, 2004

Magnetic evolutionMagnetic evolution

Aug 16, 2004

Aug 16, 2004

Coronal FieldCoronal FieldState of least energy:State of least energy:

Potential FieldPotential Field

0 B

Aug 16, 2004

Coronal FieldCoronal FieldIncludes connectionsIncludes connectionsAR9574 to AR9570AR9574 to AR9570

(P051 (P051 N01) N01)……all under separatrixall under separatrix

surfacesurface

Aug 16, 2004

SeparatricesSeparatricesenclose loopsenclose loops

Aug 16, 2004

Coronal FieldCoronal FieldInter-connecting linesInter-connecting lines

enclosed by enclosed by separatorseparator

Aug 16, 2004

Coronal FieldCoronal FieldInter-connecting flux:Inter-connecting flux:

lA d

Potential field:Potential field:Increasing

interconnectioninterconnection

AR9574AR9574

P051P051

Aug 16, 2004

Flux in 171A loopsFlux in 171A loopsAssumptionsAssumptions

1.1. Each Each looploop is a field-line bundle (flux is a field-line bundle (flux tube)tube)

2.2. Loops/flux tubes : Loops/flux tubes : x-sectionx-section3.3. Loop track flux tube for entire lifeLoop track flux tube for entire life4.4. No flux tube re-appears in 171 ANo flux tube re-appears in 171 A

Aug 16, 2004

Flux in 171 A loopsFlux in 171 A loops

1. Each 1. Each looploop is a field-line bundle ( is a field-line bundle (flux tubeflux tube))

Aug 16, 2004

Flux in 171 A loopsFlux in 171 A loops

Cummulative loop areasCummulative loop areas

loopsloops

Flux if BFlux if B00 = 30 = 30 GG

Flux in pot’lFlux in pot’lmodelmodel

Aug 16, 2004

Reconnection observedReconnection observed Flux in pot’lFlux in pot’lmodelmodel

24 hour delay24 hour delay

IncompleteIncompletereconnectionreconnection

Burst of reconnectionBurst of reconnection10101616 Mx/sec = 100 MV Mx/sec = 100 MV

Aug 16, 2004

The story of the loopsThe story of the loops

density lower boundsdensity lower bounds

radiative cooling timeradiative cooling time(upper bound on life)(upper bound on life)

life

time

life

time

heatingheating

RTV equilibriaRTV equilibria

Aug 16, 2004

The story of the loopsThe story of the loopsYohkoh SXTYohkoh SXT TRACE 171 ATRACE 171 A

950,000 K950,000 K~3,000,000 K~3,000,000 K

movie

Loops are hot (~3MK) after reconnection…Loops are hot (~3MK) after reconnection…Gradually cool into TRACE pass-bandGradually cool into TRACE pass-band

(All of them?)(All of them?)

Aug 16, 2004

There were no flaresThere were no flares

Reconnection burstReconnection burst

Aug 16, 2004

Model of energy storageModel of energy storageUnconstrained minimum: 0 B

Flux Flux (v)(v) linking poles linking poles

0

WWpotpot

WW

Aug 16, 2004

Model of energy storageModel of energy storageConstrain Flux & minimize energy…

0

WWfcefce

WWpotpot

WW

L

W2

2)v(

WW

Flux Constrained Flux Constrained EquilibriumEquilibrium(Longcope 2002)(Longcope 2002)

Aug 16, 2004

Model of energy storageModel of energy storageLowest Lowest

Energy w/ Energy w/ fixed fixed

Flux Flux Constrained Constrained EquilibriumEquilibrium(Longcope 2002)(Longcope 2002) • Current-freeCurrent-free

except …except …

Aug 16, 2004

Model of energy storageModel of energy storageFlux Flux

Constrained Constrained EquilibriumEquilibrium(Longcope 2002)(Longcope 2002) • Current-freeCurrent-free

except …except …• Current SheetCurrent Sheet @ separator@ separator (())• Mag. EnergyMag. Energy in excess ofin excess of potentialpotential W(W())

Lowest Lowest Energy w/ Energy w/

fixed fixed

Aug 16, 2004

Steady Reconnection?Steady Reconnection?

A01.0)(

40

2

IS

BS

CS

CS 24

1 0 BdICS lB

2/1CSArx S

= 4 months= 4 months

Sweet-Parker:Sweet-Parker:

Aug 16, 2004

Comparison of scalesComparison of scales

2/1CSS

Sweet-Parker:Sweet-Parker:

c/c/pipi

ii

Aug 16, 2004

Role(s) of Current SheetRole(s) of Current SheetSite of Site of

localizedlocalizedreconnectionreconnection

10101818 Mx of newly Mx of newlyreconnectedreconnected flux flux

(1% of (1% of ))

Aug 16, 2004

Role(s) of Current SheetRole(s) of Current Sheet

10101818 Mx of newly Mx of newlyreconnected fluxreconnected flux

(1% of (1% of ))

ReleasesReleasesE ~ I E ~ I

~ 10~ 102828 ergs ergs

Aug 16, 2004

Role(s) of Current SheetsRole(s) of Current Sheets

0

WWfcefce

WWpotpot

WW

WW

Energy storage:Energy storage:W accumulatesW accumulatesfor 24 hrs.for 24 hrs.prior to reconn’prior to reconn’burstburst

Rapidly releasedRapidly releasedvia local processvia local process

302

1052

L

W

Aug 16, 2004

SummarySummary1.1. AR 9574: Example of reconnection AR 9574: Example of reconnection

between new & old active regionsbetween new & old active regions2.2. Reconnection occurs in brief (6 Reconnection occurs in brief (6

hour) hour) burstburst after after delaydelay of ~24 hours of ~24 hours3.3. Produces dozens of ~10Produces dozens of ~1018 18 Mx loopsMx loops4.4. Observed flux accounts for 10% - Observed flux accounts for 10% -

30% of maximum allowed (partial 30% of maximum allowed (partial reconn.)reconn.)