Inferred rotation rate

Fits to tachocline

Kosovichev fit

Kosovichev (1996; ApJ 469, L61)

Kosovichev fit

Rotational inversion

Tests on artificial data

Charbonneau et al. (1999; ApJ 527, 445)

Analysis of LOWL data

Charbonneau et al. (1999; ApJ 527, 445)

Analysis of GONG and MDI

Basu & Antia (2003; ApJ 585, 553

The base of the convection zone Model S

Model 31

Model 31:

Subadiabatic overshoot

(Rempel 2004; ApJ 607, 1046)

Oscillatory signal from base of convection zone

Monteiro et al. (1994; A&A 283, 247)

Analysis of oscillatory signal

Zonal flowsRotation rate - average value at solar minimum

Vorontsov et al. (2002; Science 296, 101)

Tachocline oscillations

See Howe et al. (2000; Science 287, 2456)

● GONG-RLS

▲MDI-RLS

∆ MDI-OLA

Basu & Antia (2001; ApJ 324, 498)

Jets in the tachocline?

Dipakti, Gilman, C-D, Thompson

Jets in the tachocline?

Observations of tachocline jets

(for inclusion in Monday morning discussion on observations lead by Christensen-Dalsgaard)

JETS IN THE SOLAR TACHOCLINE AS DIAGNOSTICS OF GLOBAL MHD

PROCESSES THERE

J. Christensen-Dalsgaard, Univ. of Aarhus, Denmark

T. Corbard, Obs. de la Cote d’Azur, France

M. Dikpati, HAO/NCAR, USA

P. A. Gilman, HAO/NCAR, USA

M. J. Thompson, Univ. of Sheffield, UK

Inversion of rotational splittings from GONG Inversion of rotational splittings from GONG observations observations

Goal: determine rotation rate as function of latitude and distance from center

Use individual 108-day data (three GONG months) and one year averages

Inversion Techniques:

OLA: Optimal combination of data to find localized averages of rotation rate, controlling also solution error

RLS: Least-squares fit to data, regularized by minimizing also second derivative of solution

Results from helioseismology Results from helioseismology

First 8 panels show differences between individual three-GONG-months sets and the reference 1996 average,

for 2002 (the year of the highest signal). Last panel

repeats the difference for the yearly average for 2002.

Results from helioseismologyhelioseismology (continued)

First 2 panels are average solution and error for 1996,

used as reference. Remaining panels show difference between

yearly averages and 1996.

Results from helioseismology (continued)

R L S O L A

Jet a

mpl

itud

e (n

Hz)

Jet a

mpl

itud

e (n

Hz)

Dep

th (

R )

Dep

th (

R )

Lat

itud

e (d

egre

e)

Lat

itud

e (d

egre

e)