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Heating from Reconnection Quantified. Dana Longcope Montana State University. Acknowledgments:. Erik Aver Jonathan Cirtain Charles Kankelborg Dave McKenzie Jason Scott Alexei Pevtsov Robert Close Clare Parnell Eric Priest NASA grant NAG5-10489 NSF grant ATM 97227. MSU. NSO Sac Peak.

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Heating from Reconnection Quantified

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Heating from reconnection quantified l.jpg

Heating from ReconnectionQuantified

Dana LongcopeMontana State University


Acknowledgments l.jpg

Acknowledgments:

  • Erik Aver

  • Jonathan Cirtain

  • Charles Kankelborg

  • Dave McKenzie

  • Jason Scott

  • Alexei Pevtsov

  • Robert Close

  • Clare Parnell

  • Eric Priest

  • NASA grant NAG5-10489

  • NSF grant ATM 97227

MSU

NSO Sac Peak

St. Andrews


Reconnection heating theory l.jpg

Reconnection Heating: Theory

  • Parker 1972, Parker1983:

    “Topological dissipation”

  • Tucker 1973, Levine 1974

    Dissipation @ current sheets

  • Heyvaerts & Priest 1984

    Taylor relax’n after QS evol’n

  • van Ballegooijen 1985

    Dissipation of turbulent structure

  • Parker 1988, Cargill 1993, 1994, …

    Nanoflares

  • Longcope 1996, Aly & Amari 1997

    QS Formation + rapid elimination of current sheets

(Parker 1972)

=reconnection?


Heating from reconnection l.jpg

Heating from Reconnection

Heating: P [ ergs/sec ]

Reconnection magnetic dissipation

Prx[ ergs/sec ]

P = Prx

[Begging the question?]


Heating from reconnection5 l.jpg

Heating from Reconnection

Heating: P [ ergs/sec ]

Reconnection flux transfer

F[ Mx/sec ]

Reconnection

heating 

P = CF m

m>0


Reconnection heating l.jpg

Reconnection Heating

P = CF m

  • Quasi-static models:

tD << tev

Heyvaerts & Priest 1984

Longcope 1996

Aly & Amari 1997

P ~ v

P = IqrxF

m = 1

Units of constant: Amps


Reconnection heating7 l.jpg

Reconnection Heating

P = CF m

2. Resistive dissipation:

Parker 1983, 1988

van Ballegooijen 1985

tD ~ tev

P ~ v2

P =(F)2/ R

m = 2

Units of constant: Mhos


Quantifying heating l.jpg

Quantifying Heating

Pevtsov et al. 2003

ARs

XBPs


Quantifying reconnection l.jpg

Quantifying Reconnection

  • What is F?

  • What is F?

    • Which field lines change?

    • Where does the change occur?

Average Heating  General setting:

assume avg. fieldline is recycled once

in time trcyc


Quantifying reconnection10 l.jpg

Quantifying Reconnection

Pevtsov et al. 2003

ARs

XBPs


Whither withbroe noyes l.jpg

Whither Withbroe & Noyes?

Quiet Sun: <|Bz|> ~ 10 Mx/cm2

(Lites 2002)

 Fx ~2 x 104ergs/sec/cm2

(Pevtsov et al. 2003)

F ~ Fx /c=3 x 105ergs/sec/cm2

(Withbroe & Noyes 1977)

c ~ 0.1


Specific case ar 9574 l.jpg

Specific Case: AR 9574

Longcope et al. 2004

PHOTOSPHERE

2001 Aug 11, 1:35

CORONA

  • Emerging AR

  • Interconnections

  • How much

  • reconnection?

movie

TRACE 171A (106 K Plasma)


P spheric flux sources l.jpg

P-spheric flux sources

emergence begins


Coronal model l.jpg

Coronal Model

Interconnecting flux

separator


Finding all the loops l.jpg

Finding all the loops

Peaks in a

“slit”


Slide16 l.jpg

Separatrices

enclose loops


Reconnection observed l.jpg

Reconnection observed

Y Flux in pot’l

model

(Longcope et al. 2004)

24 hour delay

Burst of reconnection

1016 Mx/sec = 100 MV


Energy release l.jpg

Energy release

I~ 3 x 1010 A

Transfer flux DF

Liberate energy DW

DW ~ DFIqrx

Dissipation? (NO)


Quiet sun case xbp1 l.jpg

Quiet Sun Case: XBP1

TRACE & SOI/MDI observations 6/17/98

(Kankelborg & Longcope 1999)


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Quantifying Reconnection

  • Poles

  • Converging: v = 218 m/sec

  • Potential field:

    - bipole

    - changing

     1.6 MegaVolts

    (on separator)


Surveys of xbps l.jpg

Surveys of XBPs

  • Archival SOHO data

  • EIT + MDI images

  • Visually ID XBPs

    in EIT 195A

  • Extract bipole

    prop’s from 12 MDI

    images (@15min)

(Longcope et al. 2000,

Aver & Longcope 2005)


Surveys of xbps22 l.jpg

Surveys of XBPs

149 XBPs

vr

15o

v

d

(Aver & Longcope 2005)

F+

F=(F++F-)/2

t=d/vr


Aver longcope 2005 l.jpg

(Aver & Longcope 2005)

P

Diverging

bipoles:

No Corr’n

B0=10 G

Converging

bipoles:

P strongly

correlates

w/ reconn’n

rate proxies

1 G

P

Iqrx=1011 A

F/t

vrF


Converging vs diverging l.jpg

Converging vs. Diverging

convergence

(closing)

divergence

(opening)

time

reconnected flux


Coronal recycling time l.jpg

Coronal recycling time

(Close, Parnell, Longcope & Priest 2004)

240 Mm x 240 Mm

quiet Sun region

  • Identify sources

  • Coronal field from

  • potential extrap’n

50 MDI m-grams @ 15 min


Coronal recycling time26 l.jpg

Coronal recycling time

Fa= p-spheric

Flux in source a

yi = interconn-ecting flux in domain i

Flux balance:

“All flux goes somewhere”

Change

over Dt

submergence/emergence

Coronal reconnection


Coronal recycling time27 l.jpg

Coronal recycling time

Recycling by emergence or submegence

~ 15 hours

(cf. Hagenaar

et al. 2003)

3 hours

1.4 hours

Recycling by reconnection

2 diff. methods

of elimating Si


Summary l.jpg

Summary

  • Heating of individual structures:P ~F

  • Suggests Quasi-static reconnection heating

    P=IqrxFwithIqrx=2 x 105trcyc

  • Emerging AR (9574):

    • Reconnection delayed by ~24 hours

    • F = 260 MV, I=3 x 1010 A

    • Heating after reconnection

  • XBPs: F ~1 MV, I~ 109 A

    • Convergence/divergence dichotemy

    • trcyc ~2 hours


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