Integrating Global MHD Models with SECCHI Observations

Pete Riley, Zoran Mikic, Jon Linker, Roberto Lionello, and Slava Titov

SAIC, San Diego, California.

R. Howard and A. VourlidasNRL, Washington, DC.

5th SECCHI Consortium Meeting: SECCHI First LightsOrsay, March 5 - 8, 2007

Overview

• Our MHD Approach• Modeling the ambient solar wind• Modeling CMEs• The SAIC-SECCHI modeling website• Summary

Ambient Solar Wind: Eclipse Prediction

Longitude

Latit

ude

CR2040+CR2041 (Feb 18 – Mar 17, 2006)

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Ambient Solar Wind: Eclipse Prediction

*Photo credit: The eclipse photo was taken by the Williams College Eclipse Expedition (Jay Pasachoff, Bryce Babcock, Steven Souza, Jesse Levitt, Megan Bruck, Shelby Kimmel, Paul Hess, Anna Tsykalova, and Amy Steele), with support from NSF/NASA/National Geographic.

Image from Greece: Willams College Expedition*Simulated White Light

Magnetic field lines and Photospheric magnetic field

Ambient Solar Wind: Eclipse Prediction

Image from Egypt: Jean Mouette**

**Photo credit: Courtesy of Jean Mouette and Serge Koutchmy, CNRS (France).

MHD Simulation Observations

max Br ≈115G in AR

Modeling the May 12, 1997 CME

Energization of the Magnetic Field• Active region magnetic fields have free magnetic energy, i.e. W > Wpot

Necessary for eruption• Unfortunately, vector magnetograms available for AR8038 are of poor quality

We must energize the magnetic field in an ad hoc way• We apply a flux preserving vortical flow :

• The direction of the twist matches the sign of (= Jz/Bz) for linear FF calculation (Liu, JASTP, 2004).

Shear Flow Introduced to Build Energy

smax = 0

smax = 0.056 rad

smax = 0.013 rad

smax = 0.11 rad

Simulated Emission on May 11, 1997

-1 0 1 2 3 4 -1 -.1 .8 1.7 2.6 3.5

-2 -1.2 -.4 .4 1.2 2 2.8 0 1 2 3 4

Log10(DN/s)

Log10(DN/s)

EIT 171Å EIT 195Å

EIT 284Å SXT (composite)

Observed Emission on May 11, 1997

-1 0 1 2 3 4 -1 -.1 .8 1.7 2.6 3.5

-2 -1.2 -.4 .4 1.2 2 2.8 0 1 2 3 4

Log10(DN/s)

Log10(DN/s)

EIT 171Å EIT 195Å

EIT 284Å SXT (composite)

Sigmoidal StructureSimulated EIT 195Å Observed EIT 195Å

Propagation of the Simulated CME in the Corona

6.8 hours after Flux Cancellation begins

8.8 hours7.8 hours

Polarization Brightness

Magnetic Field Lines

Longitude of Observer: 55 Deg.

View from N. Pole

Observer

Meridional View

N CME

Longitude of Observer: 99 Deg.

View from N. Pole

Observer

Meridional View

N

CME

Longitude of Observer: 143 Deg.

View from N. Pole

Observer

Meridional View

N

CME

Longitude of Observer: 123 Deg. Longitude of Observer: 168 Deg.

STEREO B STEREO A

STEREO Observations: 1 year (~44 deg. separation)

Longitude of Observer: 99 Deg. Longitude of Observer: 190 Deg.

STEREO B STEREO A

STEREO Observations: 2 years (~88 deg separation)

Longitude of Observer: 77 Deg. Longitude of Observer: 213 Deg.

STEREO B STEREO A

STEREO Observations: 3 years (~132 deg separation)

Summary• We have continued to develop and improve our global MHD model of

the solar corona and inner heliosphere;• Ambient solar wind model can reproduce essential features of coronal

and in situ observations;• New CME results are very promising: Some “classic” emission and

white light signatures of CMEs are produced;• New website will make these modeling results available to scientific

community:• iMHD.net/stereo• Username: stereo• Password: ******

• We welcome input from SECCHI community in developing new tools for the website

Extra Slides