Monday, May 20, 2013

1305.4006 (F. Giannattasio et al.)

Diffusion of solar magnetic elements up to supergranular spatial and temporal scales    [PDF]

F. Giannattasio, D. Del Moro, F. Berrilli, L. Bellot Rubio, M. Gosic, D. Orozco Suarez
The study of spatial and temporal scales on which small magnetic structures (magnetic elements) are organized in the quiet Sun may be approached by determining how they are transported on the solar photosphere by convective motions. The process involved is diffusion. Taking advantage of Hinode high spatial resolution magnetograms of a quiet Sun region at the disk center, we tracked $20145$ magnetic elements. The large field of view ($\sim50$ Mm) and the long duration of the observations (over $25$ hours without interruption at a cadence of 90 seconds) allowed us to investigate the turbulent flows at unprecedented large spatial and temporal scales. In the field of view, in fact, an entire supergranule is clearly recognizable. The magnetic elements displacement spectrum shows a double-regime behavior: superdiffusive ($\gamma=1.34\pm0.02$) up to granular spatial scales ($\sim1500$ km), and slightly superdiffusive ($\gamma=1.20\pm0.05$) up to supergranular scales.
View original: http://arxiv.org/abs/1305.4006

No comments:

Post a Comment