Embed Size (px)
DESCRIPTION
Coronal loops formed by separator reconnection: The birth & life of AR9574. Dana Longcope Montana State University. Collaborators:. Jonathan Cirtain Dave McKenzie Jason Scott. MSU. Support:. NASA grant NAG5-10489 Isaac Newton Institute, Cambridge. Observations of Reconnection. - PowerPoint PPT Presentation
Citation preview
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
Observations of Observations of ReconnectionReconnection
Flare Flare (Sweet)(Sweet)
CME CME (Lin & Forbes)(Lin & Forbes)Jet Jet (Shimojo & Shibata)(Shimojo & Shibata)
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
Flux Emergence:Flux Emergence:A new setting for studying A new setting for studying
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 B
AR9570AR9570 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 B
AR9570AR9570 AR9570
AR9574AR9574AR9574
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
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
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
Timeline of emergenceTimeline of emergence
00:0000:00 12:0012:00 00:0000:00 12:0012:00
Aug 10, 2001Aug 10, 2001 Aug 11, 2001Aug 11, 200100:0000:00
PHOTOSPHERE
CORONA
7:347:34
Aug 16, 2004
Why this is reconnectionWhy this is reconnection
EmergeEmerged fluxd flux
Reconnected fluxReconnected flux
Old fluxOld flux
Baum &Baum &BratenahlBratenahl
19761976
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
totaltotal
loopsloops
43 loops43 loopsidentifiedidentified
11stst loop: loop:(probably)(probably)
interconnectsinterconnects
11stst loop: loop:definitelydefinitely
interconnectinginterconnecting
loop flurry loop flurry ~9:00~9:00
171
A in
ten
sity
171
A in
ten
sity
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 Field
State 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 Field
Inter-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 tracks flux tube for entire lifeLoop tracks 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
P-spheric Trigger? P-spheric Trigger? Response?Response?
loop flurry loop flurry ~9:00~9:00
24 hour delay24 hour delay
Aug 16, 2004
There were no flaresThere were no flares
Reconnection burstReconnection burst
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 t
ime
life t
ime
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
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 storage
Lowest 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 B
dICS 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 Sheet
Site of Site of localizedlocalized
reconnectionreconnection
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
30
2
1052
L
W
Aug 16, 2004
SummarySummary
1.1. AR 9574: unambiguous reconnectionAR 9574: unambiguous reconnection
2.2. Reconnection in brief (6 hour) Reconnection in brief (6 hour) burst burst after after delaydelay of ~24 hours of ~24 hours
3.3. Separator reconnectionSeparator reconnection
4.4. Trigger? … No evidence in p-sphereTrigger? … No evidence in p-sphere
5.5. Produces scores of ~10Produces scores of ~1018 18 Mx loopsMx loops
6.6. Observed flux accounts for 10% - 30% Observed flux accounts for 10% - 30% of maximum allowed (partial of maximum allowed (partial reconnection)reconnection)
