SUNRISE/IMaX Observations of Convectively Driven Vortex Flows in the Sun
Abstract
We characterize the observational properties of the convectively driven vortex flows recently discovered on the quiet Sun, using magnetograms, Dopplergrams, and images obtained with the 1 m balloonborne SUNRISE telescope. By visual inspection of time series, we find some 3.1 × 10^{3} vortices Mm^{2} minute^{1}, which is a factor of ~1.7 larger than previous estimates. The mean duration of the individual events turns out to be 7.9 minutes, with a standard deviation of 3.2 minutes. In addition, we find several events appearing at the same locations along the duration of the time series (31.6 minutes). Such recurrent vortices show up in the proper motion flow field map averaged over the time series. The typical vertical vorticities are lsim6 × 10^{3} s^{1}, which corresponds to a period of rotation of some 35 minutes. The vortices show a preferred counterclockwise sense of rotation, which we conjecture may have to do with the preferred vorticity impinged by the solar differential rotation.
 Publication:

The Astrophysical Journal
 Pub Date:
 November 2010
 DOI:
 10.1088/20418205/723/2/L139
 arXiv:
 arXiv:1009.1992
 Bibcode:
 2010ApJ...723L.139B
 Keywords:

 convection;
 Sun: granulation;
 Sun: photosphere;
 Sun: surface magnetism;
 Astrophysics  Solar and Stellar Astrophysics
 EPrint:
 To appear in ApJL. 5 Figs, 4 pages. The two animations associated with the work can be downloaded from http://www.iac.es/proyecto/solarhr/imaxvortex.html References updated in V2