7/10/09

Subsurface Circulations within Sun's Active Regions


I worked closely with Brad Hindman from the Juri Toomre Group; he came to me about doing some figures for a paper he was publishing titled "Subsurface Circulations within Active Regions" for The Astrophysical Journal. Brad does a lot with Laboratory for Computational Dynamics (LCD) which supports fundamental research on helioseismology and convection and dynamo theory. The scientists at LCD study the dynamics inside stars with helioseismology and design large-scale computer simulations of convection, turbulence, and dynamo processes within stars. They work on a pretty intense TeraGrid network which is basically clusters of supercomputers tied together across the nation. Its pretty neat stuff!

I just realized that this is my first published astrophysics project. I'm breaking into the astrophysics scene!

The full citation for the paper is:
Subsurface Circulations within Active Regions
Bradley W. Hindman, Deborah A. Haber, and Juri Toomre 2009 ApJ 698 1749-1760 doi: 10.1088/0004-637X/698/2/1749


  • Clients: Juri Toomre Group and Brad Hindman

  • Related Links: The Astrophysical Journal
  • 7/8/09

    Monodromy

    I worked with Fellow Heather Lewandowski on making this graphic for the JILA Research highlight and for the JILA AMO site. Heather's group did a series of experiments with the classical system of a pendulum on a spring which has monodromy. Monodromy is a term that has been applied in mathematics to systems that run around a singularity; however, there havn't been too many lab experiments involving monodromy. Heather's group decided to do several experiments in order to see if the systems tested had monodromy. I never heard of monodromy, but it was interesting learning how they were essentially doing these classical experiments which would help give them more insight into how other systems might also display these behaviors. The classical monodromy confirmed in the pendulum-on-a-spring experiment is analogous to the bending and stretching behavior of a CO2 molecule.

    I used Maya for this project because it was the easiest and quickest way to depict this classical experimental setup of monodromy (pretty easy to model the springs in Maya and I didn't want to draw it in Illustrator/Photoshop). In a three-dimensional spherical pendulum, for example, the singularity would correspond to the "straight up" position. However, pure bouncing motions around this position tend to be unstable. Because this instability is straight upward against gravity, any small deviation from purely vertical results in motion that could loop around the singularity. It is pretty interesting stuff and I recommend that you read the JILA Highlight article and article published in Physical Review Letters by Heather's Group to find more about the experiment and monodromy. Eventually I would like to take my Maya 3d file and really animate it. The motion is interesting in the context of monodromy. I hate "never having enough time" for the animating parts of these projects. There is always an endless list of new projects getting in the way (i need another me!).

    They apparently used my JILA camera (Panasonic DVX100A) to record video data that they gathered from the experiments. I remember the camera being loaned out for several months (almost a year) which was fine because I wasn't using the camera for any immediate projects myself. I thought it was pretty cool that they were able to use the features/controls of that camera for their experiment. The DVX100A is a notorious camera (known for its low cost and pretty high quality) used widely in the indie film industry and various other productions. Now the JILA DVX100A has another checked "has been used for" use: a classical physics experiment camera.



  • Clients: Heather Lewandowski Group

  • Related Links: JILA Research Highlight article
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