HR: 08:30h
AN: SP11C-01    [Abstracts]
TI: Large-Scale Solar Photosphere Simulations
AU: * Wray, A
EM: Alan.A.Wray@nasa.gov
AF: NASA Ames Research Center, MS T27A-1, Moffett Field, CA 94035-1000 United States
AU: Mansour, N N
EM: Nagi.N.Mansour@nasa.gov
AF: NASA Ames Research Center, MS T27A-1, Moffett Field, CA 94035-1000 United States
AU: Kosovichev, A
EM: sasha@solar.stanford.edu
AF: HEPL, Stanford University, Stanford, CA 94305 United States
AB: We have developed a 3D, compressible radiative-hydrodynamics code for simulating the upper solar photosphere and lower atmosphere, from depths of a few 10's of megameters below to an altitude of a few hundred kilometers above the visible surface. Real gas opacities and equation of state are used, and the radiation is captured through full 3D solution of the radiative transfer equation in opacity bands. The code is fully parallelized using the Message-Passing Interface (MPI) standard, allowing execution on both distributed and shared-memory architectures. We have benchmarked the code on the NASA Columbia system at Ames (an SGI Altix computer), obtaining near-ideal, linear scaling for a 500× 500× 500 node spatial mesh using from 1 to 500 processors. This scaling behavior gives us confidence that the code can be used to run large meshes effectively on large numbers of processors. We will show preliminary results from a simulation of a box 20 Mm × 20 Mm × 18 Mm at a resolution (Δ x) of approximately 40km, with a 512³ grid. Granular and intergranular lane structure and dynamics, turbulent statistics, thermal, and radiative properties will be described and compared to observations. Testing of subgrid-scale turbulence models will be discussed.
DE: 7529 Photosphere
SC: Solar Physics Division - AAS [SP]
MN: 2005 Joint Assembly