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From detailed magneto-convection simulations to modelling the
convection zone-corona system
Mats CarlssonInstitute of Theoretical Astrophysics,
University of OsloMonterey February 14 2006
Detailed simulations of magnetoconvection
•Optimization of observables
•Calibration of observables
•Interpretation
•Current status
•Future prospects
Simulations of convection zone - corona
•Nordlund/Stein code
•multi-group opacities, 4 bins
•Initial field 250G, vertical, single polarity
•253x253x163 simulation
•RT each snapshot, 2728 frequency points
•Line blanketing: 845 lines
MHD simulation of Solar magneto-convection
G-band spectral region
Solar atlasSimulation
G-band synthetic image
Comparison with observations
Simulation, mu=0.6Observation, mu=0.63
Vertical velocity
Line wingLine center
Velocity response function
Spectrum from simulation
Smeared with telescope+atm PSF
Observations
Velocity determination
Modelling coronal heating
•Magnetic field from MDI•Potential field extrapolation
•Footpoint motion statistically described•Conduction and thin losses included•Chromosphere with artificial heating/cooling function
Gudiksen & Nordlund 2005
Piecing it all together
•16x8x12 Mm (2 Mm below, 10 Mm above)
•Open boundaries
•Multi-group opacities (4 bins) with scattering
•Conduction along field-lines
•Optically thin losses in corona
•Various initial magnetic field configurations
Hansteen 2004
3D model from convection zone to corona
2D version
QuickTime™ and aGIF decompressor
are needed to see this picture.
nx=128, dx=130 km
2D version
QuickTime™ and aGIF decompressor
are needed to see this picture.
nx=512, dx= 32 km
Future modelling
•Convection zone
•multi-group opacities
•selected opacity sampling
•Magnetoconvection
•20 km resolution, 6 Mm x 6 Mm 300x300
•Supergranulation
•48 Mm x 48 Mm, 50 km resolution 1000x1000
Future modelling•Chromosphere
•Scattering
•approximate cooling in H, CaII, MgII
•time dependent H-ionization (implicit)
•CO chemistry (implicit)
•Corona
•Conduction along field lines (implicit)
Future modelling
•3D Radiation MHD simulations from convection zone to corona necessary but also within reach
•Methodology known
•Several groups active
•Future of chromospheric modelling is promising!