Simulation of large-scale flows at the solar surface

Technical Report · Sun Oct 15 04:00:00 EDT 1989

OSTI ID:6515267

Simon, G W; Weiss, N W

A simple analytic axisymmetric function will represent the radial outflow associated with an isolated convection plume at the solar surface. The vertical velocity can be deduced from the continuity equation. A regular cellular pattern of convection can be created by superposing a number of such sources. Our motivation for this study came from the large-scale horizontal motions observed by the SOUP instrument on Spacelab 2. The flow pattern is simulated as visible in three different regions covered by the SOUP observations. In each case a superposition of our plume functions mimics the observed mesogranular and supergranular motions remarkably well. The model can be improved by using the same procedure to represent sinks as well as sources in the observed velocity field. We use these model flows to compute the motion of passive test particles (corks) which accumulate in a network that outlines mesogranular cells. The cork patterns closely resemble the magnetic network observed at the time of the SOUP measurements. Detailed comparisons suggest that magnetic flux tubes are affected more by outflow from sources at the centers of mesogranules than by flow into sinks within the network.

• Research Organization: Air Force Geophysics Lab., Hanscom AFB, MA (USA)
• OSTI ID: 6515267
• Report Number(s): AD-A-223607/3/XAB; GL-TR--90-0160
• Country of Publication: United States
• Language: English

Related Subjects

640104* -- Astrophysics & Cosmology-- Solar Phenomena
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
ANALYTICAL SOLUTION
ATMOSPHERES
CONVECTION
ENERGY TRANSFER
EQUATIONS
FLUID FLOW
GAS FLOW
HEAT TRANSFER
MAGNETIC FIELDS
MAGNETIC FLUX
MASS TRANSFER
MOTION
PARTICLES
SOLAR ACTIVITY
SOLAR ATMOSPHERE
SOLAR GRANULATION
VELOCITY