Quick search Find article
Quick search
Find article

SUBSURFACE CIRCULATIONS WITHIN ACTIVE REGIONS

FREE ISSUE

Bradley W. Hindman1, Deborah A. Haber2 and Juri Toomre1

Show affiliations


Using high-resolution ring analysis, we deduce subsurface flows within magnetic active regions and within the quiet Sun. With this procedure, we are capable of measuring flows with a horizontal spatial resolution of 2° in heliographic angle (or roughly 20 Mm). From the resulting flow fields we deduce mean inflow rates into active regions, mean circulation speeds around active regions, and probability density functions (PDFs) of properties of the flow field. These analyses indicate that active regions have a zonal velocity that exceeds that of the quiet Sun at the same latitude by 20 m s–1, yet active regions advect poleward at the same rate as the quiet Sun. We also find that almost all active regions possess a mean inflow (20-30 m s–1) and a cyclonic circulation (≈5 m s–1) at their peripheries, whereas their cores, where the sunspots are located, are zones of strong anticyclonic outflow (≈50 m s–1). From the PDFs, we find that active regions modify the structure of convection with a scale greater than that of supergranulation. Instead of possessing an asymmetry between inflows and outflows (with a larger percentage of the surface occupied by outflows), as is seen in the quiet Sun, active regions possess symmetric distributions.


Keywords

MHD; Sun: activity; Sun: helioseismology; Sun: magnetic fields; Sun: oscillations; Sun: rotation


Dates

Issue 2 (2009 June 20)

Received 2008 December 22, accepted for publication 2009 April 21

Published 2009 June 3



  1. Subsurface Circulations within Active Regions

    Bradley W. Hindman et al. 2009 ApJ 698 1749

  2. Hidden SU(4) symmetry in bilayer quantum well at integer filling factors

    V I Fal'ko et al 2001 Phys.-Usp. 44 49

  3. Design and analysis of a high pressure piezoelectric actuated microvalve

    I Fazal and M C Elwenspoek 2007 J. Micromech. Microeng. 17 2366

  4. On Strong Mass Segregation Around a Massive Black Hole: Implications for Lower-Frequency Gravitational-Wave Astrophysics

    Miguel Preto and Pau Amaro-Seoane 2010 ApJ 708 L42

  5. Naked singularities formation in perfect fluids collapse

    Roberto Giambò et al 2003 Class. Quantum Grav. 20 4943

  6. Micropump based on PZT unimorph and one-way parylene valves

    Guo-Hua Feng and Eun Sok Kim 2004 J. Micromech. Microeng. 14 429

  7. A relational quantum computer using only two-qubit total spin measurement and an initial supply of highly mixed single-qubit states

    Terry Rudolph and Shashank Soyuz Virmani 2005 New J. Phys. 7 228

  8. New mathematical framework for spherical gravitational collapse

    Roberto Giambo et al 2003 Class. Quantum Grav. 20 L75

  9. Spreading out of perturbations in reversible reaction networks

    Sergei Maslov et al 2007 New J. Phys. 9 273

  10. Cosmological Spacetimes from Negative Tension Brane Backgrounds

    Cliff P. Burgess et al JHEP10(2002)028

Users also read

What's this?
This innovative new feature generates a list of articles 'also read' by other users based on them reading the original article. Article abstracts citations and references are all considered and weighted accordingly. We hope that this will help you find relevant papers for your research.

  1. Helioseismic Data Inclusion in Solar Dynamo Models

View by subject




Export








Please login to access our web services, or create an account if you don't yet have one.

You must have cookies enabled in your web browser to be able to login.

Username
Password

Forgotten your password? Get a new one here.