Simulating Shocks in Solar Flares: Flux Tube Retraction Following Multiple Reconnection Events

Flux Tube Retraction Following Multiple Simultaneous Reconnection EventsDaniel GordonSupervisor: Dana Longcope

Simulating Shocks in Solar Flares:8/7/2013 8:45 AM 2007 Microsoft Corporation. All rights reserved. Microsoft, Windows, Windows Vista and other product names are or may be registered trademarks and/or trademarks in the U.S. and/or other countries.The information herein is for informational purposes only and represents the current view of Microsoft Corporation as of the date of this presentation. Because Microsoft must respond to changing market conditions, it should not be interpreted to be a commitment on the part of Microsoft, and Microsoft cannot guarantee the accuracy of any information provided after the date of this presentation. MICROSOFT MAKES NO WARRANTIES, EXPRESS, IMPLIED OR STATUTORY, AS TO THE INFORMATION IN THIS PRESENTATION.

1Presentation Outline IntroductionBackgroundThe modelPrevious results (single reconnection event)The multiple reconnection case ResultsOverviewSimilarities and differences between casesThe differences in more detailSummary & References8/7/2013 8:45 AM 2007 Microsoft Corporation. All rights reserved. Microsoft, Windows, Windows Vista and other product names are or may be registered trademarks and/or trademarks in the U.S. and/or other countries.The information herein is for informational purposes only and represents the current view of Microsoft Corporation as of the date of this presentation. Because Microsoft must respond to changing market conditions, it should not be interpreted to be a commitment on the part of Microsoft, and Microsoft cannot guarantee the accuracy of any information provided after the date of this presentation. MICROSOFT MAKES NO WARRANTIES, EXPRESS, IMPLIED OR STATUTORY, AS TO THE INFORMATION IN THIS PRESENTATION.

2IntroductionBackgroundPost-reconnection field lines act like a string under tension. What happens to the plasma in the tube in terms of density, temperature, velocity, etc?

Reconnection a significant mechanism for phenomenon involving high energy release; solar flares, CMEs.

8/7/2013 8:45 AM 2007 Microsoft Corporation. All rights reserved. Microsoft, Windows, Windows Vista and other product names are or may be registered trademarks and/or trademarks in the U.S. and/or other countries.The information herein is for informational purposes only and represents the current view of Microsoft Corporation as of the date of this presentation. Because Microsoft must respond to changing market conditions, it should not be interpreted to be a commitment on the part of Microsoft, and Microsoft cannot guarantee the accuracy of any information provided after the date of this presentation. MICROSOFT MAKES NO WARRANTIES, EXPRESS, IMPLIED OR STATUTORY, AS TO THE INFORMATION IN THIS PRESENTATION.

3IntroductionThe ModelTube dynamics well approximated by Thin Flux Tube equations (for plasma beta > diffusion rate -> gas dynamic shocks (density build up). Field line shortens as it retracts.

RDsGDSHigh thermal conductivityRD: isentropic, no gas property change ie. change in density. GDS: abrupt change in gas property. 8/7/2013 8:45 AM 2007 Microsoft Corporation. All rights reserved. Microsoft, Windows, Windows Vista and other product names are or may be registered trademarks and/or trademarks in the U.S. and/or other countries.The information herein is for informational purposes only and represents the current view of Microsoft Corporation as of the date of this presentation. Because Microsoft must respond to changing market conditions, it should not be interpreted to be a commitment on the part of Microsoft, and Microsoft cannot guarantee the accuracy of any information provided after the date of this presentation. MICROSOFT MAKES NO WARRANTIES, EXPRESS, IMPLIED OR STATUTORY, AS TO THE INFORMATION IN THIS PRESENTATION.

5IntroductionThe Multiple Reconnection Case

Multiple points of reconnection separates in to three sections.We consider the new section.How does it evolve in time?Similarities and differences to single point case?

6

ResultsOverview8/7/2013 8:45 AM 2007 Microsoft Corporation. All rights reserved. Microsoft, Windows, Windows Vista and other product names are or may be registered trademarks and/or trademarks in the U.S. and/or other countries.The information herein is for informational purposes only and represents the current view of Microsoft Corporation as of the date of this presentation. Because Microsoft must respond to changing market conditions, it should not be interpreted to be a commitment on the part of Microsoft, and Microsoft cannot guarantee the accuracy of any information provided after the date of this presentation. MICROSOFT MAKES NO WARRANTIES, EXPRESS, IMPLIED OR STATUTORY, AS TO THE INFORMATION IN THIS PRESENTATION.

7ResultsDifferences to single reconnection caseShocks collide at approx. 2.75s Field line curves at later timesV_x rarefaction wave => density drop-offField lines cease shortening

8/7/2013 8:45 AM 2007 Microsoft Corporation. All rights reserved. Microsoft, Windows, Windows Vista and other product names are or may be registered trademarks and/or trademarks in the U.S. and/or other countries.The information herein is for informational purposes only and represents the current view of Microsoft Corporation as of the date of this presentation. Because Microsoft must respond to changing market conditions, it should not be interpreted to be a commitment on the part of Microsoft, and Microsoft cannot guarantee the accuracy of any information provided after the date of this presentation. MICROSOFT MAKES NO WARRANTIES, EXPRESS, IMPLIED OR STATUTORY, AS TO THE INFORMATION IN THIS PRESENTATION.

8ResultsField line shortening: single reconnection case

Transfers magnetic -> kinetic energy, comparatively minimal energy lost to heat

8/7/2013 8:45 AM 2007 Microsoft Corporation. All rights reserved. Microsoft, Windows, Windows Vista and other product names are or may be registered trademarks and/or trademarks in the U.S. and/or other countries.The information herein is for informational purposes only and represents the current view of Microsoft Corporation as of the date of this presentation. Because Microsoft must respond to changing market conditions, it should not be interpreted to be a commitment on the part of Microsoft, and Microsoft cannot guarantee the accuracy of any information provided after the date of this presentation. MICROSOFT MAKES NO WARRANTIES, EXPRESS, IMPLIED OR STATUTORY, AS TO THE INFORMATION IN THIS PRESENTATION.

9ResultsField line shortening: double reconnection case

After shocks interact: plateau reached, thermal conversion pronouncedEnergy transfer rate doubled991778/7/2013 8:45 AM 2007 Microsoft Corporation. All rights reserved. Microsoft, Windows, Windows Vista and other product names are or may be registered trademarks and/or trademarks in the U.S. and/or other countries.The information herein is for informational purposes only and represents the current view of Microsoft Corporation as of the date of this presentation. Because Microsoft must respond to changing market conditions, it should not be interpreted to be a commitment on the part of Microsoft, and Microsoft cannot guarantee the accuracy of any information provided after the date of this presentation. MICROSOFT MAKES NO WARRANTIES, EXPRESS, IMPLIED OR STATUTORY, AS TO THE INFORMATION IN THIS PRESENTATION.

10ResultsField line bending

x (Mm) x (Mm) z (Mm) z (Mm)

From ~7s (left) tube begins to bend.Right: 11.0s As tube bends kinetic energy reconverted to magneticResultsField line bending: explanation

Alfven speed influenced by the chromosphere.Outer RDs generally slow down, inner speed up, resulting in the observed bending. ResultsDensity drop-off

Angle: 105 degAngle: 120 degt=4.0sRarefaction evacuates mass from tube centre.Degree of density deficit is angle dependent; steeper rarefaction at 120 degrees.ResultsDensity drop-off

About 60% reduction near 120 deg. Why this angle?Not special, angle varies with temperature. How?

T=3MKT=2MKT=4MKResultsDensity drop-off

Minimum angle a function of temperature.Initial steady rise with temp.Seems to even off slightly above 130 degrees.SummaryRDs collide to produce interesting effects:Tube shortening ceases at point of collision, as does conversion of energy (at least temporarily).RDs interact with (mainly) chromosphere but also GDS to cause tube bending; energy conversion continues but in reverse!Rarefaction wave produced which evacuates mass from central portion of tube, decreasing density by more than 50% in some cases - easier to explain high energy particles?Density removal not inversely proportional to angle

References Linton, M. G., & Longcope, D. W. 2006, ApJ, 642, 1177Longcope, D. W., Guidoni, S. E., & Linton, M. G. 2009, ApJ, 690, L18Guidoni, S. W., & Londcope, D. W. 2010, ApJ, 718, 1476Longcope, D. W., & Guidoni, S. E. 2011, ApJ, 740, 73Priest, E.R, 1981, Solar Flare Magnetohydrodynamics (New York: Gordon and Breach Science Publishers)

8/7/2013 8:45 AM 2007 Microsoft Corporation. All rights reserved. Microsoft, Windows, Windows Vista and other product names are or may be registered trademarks and/or trademarks in the U.S. and/or other countries.The information herein is for informational purposes only and represents the current view of Microsoft Corporation as of the date of this presentation. Because Microsoft must respond to changing market conditions, it should not be interpreted to be a commitment on the part of Microsoft, and Microsoft cannot guarantee the accuracy of any information provided after the date of this presentation. MICROSOFT MAKES NO WARRANTIES, EXPRESS, IMPLIED OR STATUTORY, AS TO THE INFORMATION IN THIS PRESENTATION.

17ResultsField line shortening (find way of graphing length)