Dynamical Implications

1
Dynamical Implications

• Juri Toomre, JILA Helioseis Deborah Haber, Brad
  Hindman Rick Bogart, Douglas Gough, Frank
  Hill, Jesper Schou, Mike Thompson
• Dynamics Nic Brummell, Sacha Brun,
  Marc DeRosa, Mark Miesch

2
Just what is inside a star ?
Arnaldo POMODORO
3
Objective 1 CZ dynamics solar dynamo

• A. Structure and dynamics of tachocline
• B. Variations in differential rotation
• C. Evolution in meridional circulation
• D. Dynamics in near-surface shear layer

Objective 2 Evolution of complexes of activity
4
Mean Angular Velocity Profiles
NEAR-SURFACE SHEAR LAYER
TACHOCLINE
HMI-land
CZ BOTTOM
5
Theoretical Solar Cycle
EMERGING LOOP
PHOTOSPHERE
LOCAL DYNAMO
ROTATION
CONVECTION ZONE
PUMPING
GLOBAL DYNAMO
BUOYANCY
TACHOCLINE
RADIATIVE INTERIOR
6
Evolution in Radial Velocity (0.96 R)
NEAR TOP OF LAYER
VIEWED IN CARRINGTON FRAME
Case E Brun, Miesch Toomre
7
Global View of Radial Velocity
8
But can we detect such giant cells by
helioseismic observation?
9
Giant cellscomplex evolving structures
10
Propagating and evolving velocity patterns
5d
10d
Time-longitude map (relative to Carrington)
at 20 degrees north
11
Big Questions Global-Scale Convection

• Why no clear or direct detection of giant
  convection cells?
• Does intense near-surface turbulence of
  granulation and supergranulation yield transport
  barrier to deflect such flows?
• May simply be very tough to detect since narrow
  downflows but wide cell scales, and they both
  evolve and propagate

12
Ring Analyses Two Successive Rotations
1997
7 Mm
CR 1923
CR 1922
13
Changing Meridional Circulation Cells
NORTH DOUBLE CELL
2001
POLEWARD FLOW NEAR SURFACE
2000
SOUTH SINGLE CELL
REVERSED FLOW AT DEPTH
1999
1998
1997
1996
Haber et al (2002)
NORTH
SOUTH
14
SSW Evolution Near Active Complexes

15
High-Resolution Ring Analysis
16
Evolution in Doppler Correlation Tracking
Lisle, DeRosa
17
Analysis Strategy

• Devise some combination of local-domain
  helioseismic probings to provide
• Nearly soon(real)-time, continuous subsurface
  flow mappings in upper 20 Mm -- fast analysis
  pipes

18
Our thrusts with rings (and time-distance)

• Re-evaluate ALL elements in current ring
  procedures mappings, ridge or ring fits, varying
  resolution across disk, line asymmetries vs
  varying background
• Devise multi-scale tiling analyses, and build
  mature 3-D inversions for flow fields
• Test all with high-resolution MDI Doppler data
  to verify procedures and codes