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Inferred rotation rate. Fits to tachocline Kosovichev fit Kosovichev (1996; ApJ 469, L61)

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Presentation on theme: "Inferred rotation rate. Fits to tachocline Kosovichev fit Kosovichev (1996; ApJ 469, L61)"— Presentation transcript:

1 Inferred rotation rate

2 Fits to tachocline

3 Kosovichev fit Kosovichev (1996; ApJ 469, L61)

4 Kosovichev fit

5 Rotational inversion

6 Tests on artificial data Charbonneau et al. (1999; ApJ 527, 445)

7 Analysis of LOWL data Charbonneau et al. (1999; ApJ 527, 445)

8 Analysis of GONG and MDI Basu & Antia (2003; ApJ 585, 553

9 The base of the convection zone Model S Model 31 Model 31: Subadiabatic overshoot (Rempel 2004; ApJ 607, 1046)

10 Oscillatory signal from base of convection zone Monteiro et al. (1994; A&A 283, 247)

11 Analysis of oscillatory signal

12 Zonal flows Rotation rate - average value at solar minimum Vorontsov et al. (2002; Science 296, 101)

13 Tachocline oscillations See Howe et al. (2000; Science 287, 2456) ● GONG-RLS ▲ MDI-RLS ∆ MDI-OLA Basu & Antia (2001; ApJ 324, 498)

14 Jets in the tachocline? Dipakti, Gilman, C-D, Thompson

15 Jets in the tachocline?

16 Observations of tachocline jets (for inclusion in Monday morning discussion on observations lead by Christensen-Dalsgaard)

17 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

18 Inversion of rotational splittings from GONG 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

19 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.

20 helioseismology Results from helioseismology (continued) First 2 panels are average solution and error for 1996, used as reference. Remaining panels show difference between yearly averages and 1996.

21 Results from helioseismology (continued) R L S O L A Jet amplitude (nHz) Depth ( R ) Latitude (degree)


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