SUPERGRANULES AS PROBES OF SOLAR CONVECTION ZONE DYNAMICS

Journal Article · Tue Apr 10 04:00:00 EDT 2012 · Astrophysical Journal Letters

DOI:https://doi.org/10.1088/2041-8205/749/1/L13· OSTI ID:22047916

Supergranules are convection cells seen at the Sun's surface as a space filling pattern of horizontal flows. While typical supergranules have diameters of about 35 Mm, they exhibit a broad spectrum of sizes from {approx}10 Mm to {approx}100 Mm. Here we show that supergranules of different sizes can be used to probe the rotation rate in the Sun's outer convection zone. We find that the equatorial rotation rate as a function of depth as measured by global helioseismology matches the equatorial rotation as a function of wavelength for the supergranules. This suggests that supergranules are advected by flows at depths equal to their wavelengths and thus can be used to probe flows at those depths. The supergranule rotation profiles show that the surface shear layer, through which the rotation rate increases inward, extends to depths of {approx}50 Mm and to latitudes of at least 70 Degree-Sign . Typical supergranules are well observed at high latitudes and have a range of sizes that extend to greater depths than those typically available for measuring subsurface flows with local helioseismology. These characteristics indicate that probing the solar convection zone dynamics with supergranules can complement the results of helioseismology.

• OSTI ID: 22047916
• Journal Information: Astrophysical Journal Letters, Journal Name: Astrophysical Journal Letters Journal Issue: 1 Vol. 749; ISSN 2041-8205
• Country of Publication: United States
• Language: English

Related Subjects

79 ASTRONOMY AND ASTROPHYSICS
ASTRONOMY
ASTROPHYSICS
CONVECTION
LAYERS
PHOTOSPHERE
PROBES
ROTATION
SEISMOLOGY
SHEAR
SUN
ZONES