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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