scholarly journals Search for Giant Cells in the Solar Convection Zone

1980 ◽  
Vol 91 ◽  
pp. 21-23 ◽  
Author(s):  
B. J. Labonte ◽  
R. Howard
Keyword(s):  
Large Scale ◽  
Convection Zone ◽  
Solar Rotation ◽  
Longitudinal Velocity ◽  
Giant Cells ◽  
Solar Convection Zone ◽  
Solar Convection ◽  
Mount Wilson Observatory ◽  
Entire Dataset ◽  
Full Disk

The Mount Wilson Observatory has obtained daily full disk digital magnetograms of the Sun since 1966, with 12 to 17 arcsecond resolution. As each magnetogram is taken, the position of the Doppler line shift compensator is also recorded, thus giving a full disk map of the longitudinal velocity. This entire dataset is currently being rereduced on a uniform basis (Howard et al., 1980), and daily arrays of residual velocities are being formed by removing large scale patterns, e.g., Earth's motions, solar rotation, limbshift. Data from the years 1972 through 1978 are used here.

scholarly journals Rotation in the solar convection zone inferred from Fabry-Perot observations of the 5-min oscillations

1988 ◽  
Vol 123 ◽  
pp. 49-52
Author(s):  
Frank Hill ◽  
David M. Rust ◽  
Thierry Appourchaux
Keyword(s):  
Lithium Niobate ◽  
Rotation Rate ◽  
Convection Zone ◽  
Solar Rotation ◽  
Inversion Method ◽  
Solar Convection Zone ◽  
Solar Convection ◽  
Fabry Perot ◽  
Full Disk ◽  
Solar Rotation Rate

Full disk observations of the 5-min solar oscillations have been obtained with a lithium niobate Fabry-Perot filter. The equatorial solar rotation rate as a function of depth has been inferred from the sectoral modes of oscillation using the Backus-Gilbert optimal averaging inversion method. The results show a rotation rate that slowly decreases over the depths of 15 to 56 Mm below the photosphere. The results are in agreement with the previous Duvall-Harvey observations.

scholarly journals Magnetoconvection Patterns in Rotating Convection Zones

1991 ◽  
Vol 130 ◽  
pp. 37-56
Author(s):  
Paul H. Roberts
Keyword(s):  
Convection Zone ◽  
Solar Surface ◽  
Giant Cells ◽  
Conclusive Evidence ◽  
The Other ◽  
The Sun ◽  
Solar Convection Zone ◽  
Solar Convection ◽  
Entire Thickness ◽  
Convective Motions

AbstractIn addition to the well-known granulation and supergranulation of the solar convection zone (the “SCZ”), the presence of so-called “giant cells” has been postulated. These are supposed span the entire thickness of the SCZ and to stretch from pole to pole in a sequence of elongated cells like a “cartridge belt” or a bunch of “bananas” strung uniformly round the Sun. Conclusive evidence for the existence of such giant cells is still lacking, despite strenuous observational efforts to find them. After analyses of sunspot motion, Ribes and others believe that convective motions near the solar surface occurs in a pattern that is the antithesis of the cartridge belt: a system of “toroidal” or “doughnut” cells, girdling the Sun in a sequence that extends from one pole to the other. Galloway, Jones and Roberts have recently tried to meet the resulting theoretical challenge, with the mixed success reported in this paper.

Large Scale Flows in the Solar Convection Zone

2008 ◽  
Vol 144 (1-4) ◽  
pp. 151-173 ◽  
Author(s):  
Allan Sacha Brun ◽  
Matthias Rempel
Keyword(s):  
Large Scale ◽  
Convection Zone ◽  
Solar Convection Zone ◽  
Solar Convection

scholarly journals Helicity–vorticity turbulent pumping of magnetic fields in the solar dynamo

2012 ◽  
Vol 8 (S294) ◽  
pp. 367-368
Author(s):  
V. V. Pipin
Keyword(s):  
Magnetic Field ◽  
Magnetic Fields ◽  
Differential Rotation ◽  
Large Scale ◽  
Convection Zone ◽  
Solar Dynamo ◽  
Solar Convection Zone ◽  
Solar Convection ◽  
Large Scale Magnetic Field ◽  
Convective Motions

AbstractThe interaction of helical convective motions and differential rotation in the solar convection zone results in turbulent drift of a large-scale magnetic field. We discuss the pumping mechanism and its impact on the solar dynamo.

scholarly journals Large-scale flows and convection at the base of solar convection zone

2006 ◽  
Vol 2 (S239) ◽  
pp. 425-430
Author(s):  
Evgeniy Tikhomolov
Keyword(s):  
Magnetic Fields ◽  
Large Scale ◽  
Convection Zone ◽  
Three Dimensional ◽  
Solar Radius ◽  
Solar Convection Zone ◽  
Solar Convection ◽  
Rotation Periods ◽  
Scale Temperature ◽  
Local Sound

AbstractDevelopment of convection in sun's outer shell is caused by reduction of effectiveness of energy transfer by radiation. Traditionally, models of solar convection are considered to be axisymmetric on the scale of solar radius. Such models provide basic understanding of convection under solar conditions. However, interpretation of a number of observable large-scale long-lived solar phenomena requires developing a non-axisymmetric approach. We present such a model in which large-scale non-axisymmetry is caused by large-scale flows such as Rossby waves and vortices. We model flows near the base of the solar convection zone. Anelastic approximation is used, which is valid for flow velocities much smaller than local sound speed. Our three-dimensional numerical simulations show that interaction of convection with large-scale flows leads to the establishment of non-axisymmetric large-scale temperature distribution. The interaction also gives rise to large-scale variations of penetration depth of convective plumes. Generation of the magnetic field by large-scale non-axisymmetric flows can explain such solar phenomena as complexes of activity, active longitudes, drifts of large-scale magnetic fields from equator to the poles, and appearance of distinct rotation periods of magnetic fields at some latitudes. We discuss a possibility of detection of large-scale non-axisymmetric flows and temperature distributions associated with them by the methods of helioseismology.

scholarly journals Helioseismic Observations of Solar Convection Zone Dynamics

2010 ◽  
Vol 6 (S271) ◽  
pp. 15-22
Author(s):  
Frank Hill ◽  
Rachel Howe ◽  
Rudi Komm ◽  
Irene González Hernández ◽  
Shukur Kholikov ◽  
...  
Keyword(s):  
Large Scale ◽  
Convection Zone ◽  
Global Analysis ◽  
Torsional Oscillation ◽  
Temporal Variations ◽  
Flare Activity ◽  
Flux Transport ◽  
Near Surface ◽  
Solar Convection Zone ◽  
Solar Convection

AbstractThe large-scale dynamics of the solar convection zone have been inferred using both global and local helioseismology applied to data from the Global Oscillation Network Group (GONG) and the Michelson Doppler Imager (MDI) on board SOHO. The global analysis has revealed temporal variations of the “torsional oscillation” zonal flow as a function of depth, which may be related to the properties of the solar cycle. The horizontal flow field as a function of heliographic position and depth can be derived from ring diagrams, and shows near-surface meridional flows that change over the activity cycle. Time-distance techniques can be used to infer the deep meridional flow, which is important for flux-transport dynamo models. Temporal variations of the vorticity can be used to investigate the production of flare activity. This paper summarizes the state of our knowledge in these areas.

scholarly journals Pumping of Rossby Waves and Vortices at the Base of the Solar Convection Zone

1998 ◽  
Vol 185 ◽  
pp. 177-178
Author(s):  
Evgeniy Tikhomolov
Keyword(s):  
Large Scale ◽  
Rossby Waves ◽  
Convection Zone ◽  
Polar Field ◽  
Field Reversal ◽  
Solar Convection Zone ◽  
Magnetic Structures ◽  
Solar Convection ◽  
Long Term Behavior

Rossby vortices excited near the base of the solar convection zone are very appealing objects for interpretation of a number of solar phenomena such as long-lived large-scale magnetic structures, the poleward drift of the axisymmetric components after the polar field reversal, and a peculiar long-term behavior of the nonaxisymmetric components (Tikhomolov and Mordvinov 1996).

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