Pioneering Works on Ring Diagram Analysis withIrene Gonzlez HernndezJess Patrn RecioSeptember 3rd, 2014

4 years period from mid 1994 to mid 1998: thesis development works of Irene.I obtained my PhD on Solar Physics on September 1994, after three years of works at NSO, Tucson, Arizona, in close contact to GONG development team and under supervision of Frank Hill.Work with Irene more a collaborative effort than a supervision work: she was a colleague during my own postdoctoral research.

1993: The IAC Helio- and Astro-seismology Group21 years ago..

At the time of my return to the Canary Islands, around March 1994, the Helioseismology group of people at the IAC was a big family.Picture taken on December 1993. Probably it was the first time I met Irene, and probably we still didn't talk about the future yet (since I was thinking on finishing my PhD defense).There were at least 6 graduate students in the group, like, Antonio Eff-Darwich, Rafael Garca, Cristina Rabello-Soares, Isabel Martn, Inmaculada Vidal and Irene Gonzlez (and still myself).Also we can see the veterans, Teo, Pere, Antonio Jimnez, Clara, Fernando and Juan Antonio Belmonte.

TON imagesComparison 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 imagesSolar rotationMeridional flowsVelocity flows synoptic maps (main thesis work)

Thesis work:Improvements on ring diagram techniques:Best images: velocity versus intensity imagesMaximum approximation to plane waves: longitude-latitude -> maximum circlesAvoiding projection effects: regions passing the center of the solar discSimplification and speeding of fitting processesRobustness of the method: retrieving artificial velocity flows in data.Extension to higher latitudes and complete longitude set

Works with Irene can be summarized on reliability of the ring diagram analysis methods, improvements of the techniques and extension of the analysis to the greatest coverage never done before.Works performed with high resolution solar images from TON and SOI, and also several tests with GONG images.Solar Surface coverage evolution (1988-1998)

Solar Surface coverage evolution (F. Hill, 1988)

Solar Surface coverage evolution (J. Patrn, 1994)

Solar Surface coverage evolution (I. Gonzlez, 1998)

Improvements on fitting methods-

Reliability of ring diagram analysisSOI velocity imagesTON Intensity images

Reliability of ring diagram analysis

Time evolution of velocity flows

Solar rotation at subphotospheric layers

Meridional flows

Synoptic maps of horizontal velocity flowsJ. Patrn; I. Gonzlez; 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. Patrn; I. Gonzlez Hernndez; 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. Gonzlez Hernndez; J. Patrn; 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. Gonzlez Hernndez; J. Patrn; 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. Gonzlez Hernndez and J. Patrn. Solar rotation in the subphotospheric layers. Solar Physics. 191(1), pp. 37 - 46. 2000.I. Gonzlez Hernndez; J. Patrn; T. Roca-Corts; 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