Predicting the Structure of the Solar Corona Using ADAPT Maps
|
The
November 13, 2012 Total Solar Eclipse: Predicting the Structure of the Solar Corona Using ADAPT Maps |
|---|
 |
The figure on the left shows the predicted polarization brightness (pB) in the solar corona for the eclipse expected on November 13, 2012 at 22:13 UTC (corresponding to the moment of greatest eclipse in the Pacific Ocean). The state of the solar corona was computed using a 3D magnetohydrodynamic (MHD) simulation. The pB signal is produced by white light scattered off electrons in the coronal plasma. The image has been radially detrended using the Newkirk vignetting function to account for the fall-off of coronal brightness with distance from the Sun. Vertical (top) is terrestrial (geocentric) north. This is the view of the Sun that would be seen by an observer on Earth with a camera aligned so that vertical is toward the Earth’s north pole. To view this image in a coordinate system aligned with solar north, click here. Click the image to see it in greater detail. |
|---|
  |
| Predicted polarization brightness (top left) together with traces of the magnetic field lines in the solar corona (top right) for the eclipse expected on November 13, 2012 at 22:13 UTC (with terrestrial north up). The Sun’s surface shows color contours of the radial component of the photospheric magnetic field as predicted by the ADAPT model. showing the location of active regions (strong magnetic fields). Click the images for higher resolution pictures. To view these images in a coordinate system aligned with solar north, click here. |
At this time of the cycle, the Sun is near it's activity maximum,
and the Sun's magnetic flux frequently evolves rapidly. The
ADAPT model can account for the surface flows and diffusion of
flux, but the emergence of signifcant new active regions can only
be accounted for when they are observed on the earthward side of
the Sun. (ADAPT can in principle incorporate new flux
estimated from helioseismic far side detections [Arge et al. 2012]
but this technique was not employed here.) Therefore, flux
that emerges outside of the earth view will not be accounted
for. This is especially relevant for east limb observations
on eclipse day. Below are shown ADAPT MAPs with data
ingested on November 2 and November 5, and the corresponding
estimates for the magnetic flux on November 13. These maps
show the radial component of the magnetic field as a function of
latitude (vertical axis) and Carrington longitude (horizontal
axis). Red shows outward directed magnetic field, and blue shows
inward directed field. A smoothed version of the map in the bottom
right corner was used for the calculations shown here. Click
on each map to view a larger image.
|
|
||||
|
|
We have made movies of the polarization brightness (pB) from our MHD simulation. This illustrates visually how the solar corona changes as a result of solar rotation. You can see a grayscale movie of pB with a black disk occulting the Sun: a GIF version (4.1 Mbytes, recommended), a QuickTime version (1.8 Mbytes), or a half-resolution GIF version (1.5 Mbytes). You can also see a movie of pB with a blue background and a black disk occulting the Sun: a GIF version (4.1 Mbytes, recommended), or a QuickTime version (3.6 Mbytes).
If your movie player can continuously loop a movie while playing it, set this option to "on" for the best effect.
C. N. Arge, C. J. Henney, J. Koller, C. R. Compeau, S. Young, D. MacKenzie, A. Fay, and J. W. Harvey, "Air Force Data Assimilative Photospheric Flux Transport (ADAPT) Model," Twelfth International Solar Wind Conference, 1216, 343 (2010).
C. N. Arge, C. J. Henney, I. G. Hernandez, W. A. Toussaint, J. Koller, and H. C. Godinez, "Modeling the Corona and Solar Wind using ADAPT Maps that Include Far Side Observations," Thirteenth International Solar Wind Conference, submitted, (2012).
J. A. Linker, Z. Mikić, P. Riley, C. Downs, R. Lionello, C. J. Henney, and C. N. Arge, "Coronal and Heliospheric Modeling Using Flux-Evolved Maps," Thirteenth International Solar Wind Conference, submitted, (2012).
J. Worden and J. Harvey, "An Evolving Synoptic Magnetic Flux map and Implications for the Distribution of Photospheric Magnetic Flux," Sol. Phys., 195, 247 (2000).
Return
to the Coronal Modeling Page 
