Michelson Doppler Imager (MDI) Main Page.
The results are reported by Laurent Gizon, Tom Duvall and Jesper Schou
in the paper "Wave-like Properties of Solar Supergranulation"
published in the January 2 issue of the journal Nature (vol. 421, pp. 43-44, 2003).
Erratum: the units on the x-axis of Fig. 1 should be microHz.
You may download a preprint of the paper in postscript or pdf format. The paper includes figures.
The NASA press release (including movies and images) is at http://www.gsfc.nasa.gov/topstory/2003/0102wave.html
The ESA press release (including movies and images) is at http://sci.esa.int/
See also SOHO Hot Shot.
Additional documents can be downloaded at
http://soi.stanford.edu/press/Nature_2Jan03 (this page).
Past MDI press releases can be found at
http://soi.stanford.edu/press/
SOHO is a mission of international cooperation between
ESA
and NASA.
Solar and Heliospheric Observatory (SOHO) Main Page.
The following images and movies help understand the results.
Topic | Sample Image | Image or Video links | Notes |
---|---|---|---|
MDI/SOHO movie of solar supergranulation |
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MPEG |
Supergranules are large convection cells. The "smooth" area near the center of the images is where the supergranules do not contribute to the signal: their motion is mostly horizontal and MDI measures only the component of motion directed towards or away from SOHO. Supergranules flow outwards from their centers, with a typical velocity of 400 m/s. |
Animation showing travelling-wave convection |
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GIF |
Although there is no net plasma flow in any direction, the pattern appears to propagate to the right of the picture. This animation illustrates how the super-rotation of superganules is really just an illusion. |