Accession Number:

ADA183687

Title:

Solar Oscillations and Convective Flows as Probes of Structure in the Subphotosphere.

Descriptive Note:

Final rept. 2 Feb 83-31 Jul 86,

Corporate Author:

JOINT INST FOR LAB ASTROPHYSICS BOULDER CO

Personal Author(s):

• Toomre,Juri
• Gebbie,Katharine B.

Report Date:

1987-04-15

Pagination or Media Count:

28.0

Abstract:

Application of inverse theory to the observation of high-degree five-minute solar oscillations has led to the detection of horizontal flows below the solar surface that are a combination of solar rotation and giant convection cells. The distinctive displacements in the centroids of the ridges evident in the power diagrams of the oscillations from one observing day to the next arise from different patterns of giant cells being rotated into view. Such observation of frequency splittings for the high degree oscillation modes, combined with refinements in the inversion of the data using optimal averaging and spectral expansions, has shown that helioseismology should permit detailed mapping of velocity and thermal structures below the solar surface. Extensive theoretical studies of fully compressible magnetoconvection have shown that flows are indeed able to concentrate magnetic fields into concentrated flux sheets that are substantially evaluated of gas. The magnetic buoyancy instabilities have been extensively studies.

Descriptors:

• *SOLAR ACTIVITY
• *PHOTOSPHERE
• BUOYANCY
• CELLS
• DETECTION
• DIAGRAMS
• DISPLACEMENT
• FLOW
• FLUX(RATE)
• FREQUENCY
• HORIZONTAL ORIENTATION
• INVERSION
• MAPPING
• OBSERVATION
• MAGNETIC FORCES
• POWER
• PROBES
• SHEETS
• SPLITTING
• STABILITY
• STRUCTURES
• SUN
• THEORY
• THERMAL PROPERTIES
• VELOCITY
• CONVECTION(HEAT TRANSFER)

Subject Categories:

• Astrophysics
• Electricity and Magnetism

Distribution Statement:

APPROVED FOR PUBLIC RELEASE