1. Pioneering Works on Ring Diagram Analysis with Irene González Hernández Jesús Patrón Recio September 3rd, 2014

2. 1993: The IAC Helio- and Astro-seismology Group 21 years ago…..

3.  TON images Comparison of fitting methods (12 to 4 parameters final fitting) Reliability of ring diagram analysis (comparison of results from TON and SOI images) Time evolution of velocity flows  SOI images Solar rotation Meridional flows Velocity flows synoptic maps (main thesis work)  Thesis work: Improvements on ring diagram techniques: Best images: velocity versus intensity images Maximum approximation to plane waves: longitude-latitude -> maximum circles Avoiding projection effects: regions passing the center of the solar disc Simplification and speeding of fitting processes Robustness of the method: retrieving artificial velocity flows in data. Extension to higher latitudes and complete longitude set

4. 4 regions / 15x60 degrees 9 regions / 45x45 degrees 120 regions / 75x360 degrees Synoptic Solar Surface coverage evolution (1988-1998)

5. 4 regions / 15x60 degrees 9 regions / 45x45 degrees 120 regions / 75x360 degrees Synoptic Solar Surface coverage evolution (F. Hill, 1988)

6. 4 regions / 15x60 degrees 9 regions / 45x45 degrees 120 regions / 75x360 degrees Synoptic Solar Surface coverage evolution (J. Patrón, 1994)

7. 4 regions / 15x60 degrees 9 regions / 45x45 degrees 120 regions / 75x360 degrees Synoptic Solar Surface coverage evolution (I. González, 1998)

8. Improvements on fitting methods

9. Reliability of ring diagram analysis SOI velocity images TON Intensity images

10. Reliability of ring diagram analysis

11. Time evolution of velocity flows

12. Solar rotation at subphotospheric layers

13. Meridional flows

14. Synoptic maps of horizontal velocity flows

15. J. Patrón; I. González; and Dean-Yi Chou and the TON team. Comparison of two Fitting Methods for Ring Diagram Analysis of Very High l Solar Oscillations. Astrophysical Journal. 485, pp. 896 - 874. 1997. J. Patrón; I. González Hernández; and Dean-Yi Chou and the TON team. Time Evolution of Horizontal Subsurface Flows in the Sun. Astrophysical Journal. 506, pp. 450 - 455. 1998. I. González Hernández; J. Patrón; and D.-Y. Chou and the TON team. On the Reliability of the Ring Diagram Analysis Method. Astrophysical Journal. 501, pp. 408 - 413. 1998. I. González Hernández; J. Patrón; and R. S. Bogart and the SOI Ring Diagram Team. Meridional Flows from Ring Diagram Analysis. Astrophysical Journal Letters. 510, pp. L153 - L156. 1999. I. González Hernández and J. Patrón. Solar rotation in the subphotospheric layers. Solar Physics. 191(1), pp. 37 - 46. 2000. I. González Hernández; J. Patrón; T. Roca-Cortés; R. S. Bogart; F. Hill; and E. J. Rhodes, Jr. A synoptic view of the subphotospheric horizontal velocity flows in the Sun. Astrophysical Journal. 535, pp. 454 - 463. 2000. Publications