Clifford Toner

NSO/T Scientific Staff

Areas of Interest

Global and Local Helioseismology, Image Restoration, Data Analysis Techniques

Recent Research Results

Toner, S. Jefferies, and T. Toutain (Observatoire de Nice) have confirmed the theoretical prediction (T. Toutain, G. Berthomieu, and J. Provost, 1999, Astronomy & Astrophysics, 344, 188) that the p-mode amplitude in the continuum peaks very near the solar limb. They also found that the low-frequency solar background decreases at the limb. The combination of low background and high oscillation signal makes the solar limb an ideal place to look for low-frequency oscillations such as g-modes. The detection of solar g-modes would substantially increase our knowledge of the deep solar interior.

Toner, S. Jefferies, R. Garcia (Service d'Astrophysique, France), and P. Palle (Instituto da Astrofisica de Canarias, Spain) have developed a data analysis technique which can substantially increase the signal-to-noise ratio in solar oscillation spectra by reducing the contamination due to incoherent noise. This allows more precise measurements of the oscillation parameters (e.g. frequency, line width, etc.) and has allowed the detection of modes that previously were lost in the background noise.

Toner has been developing an algorithm for merging GONG data at the image level . This is in preparation for the upgrade of the GONG instruments to higher resolution cameras (GONG+) so that the Project can begin using GONG data for local helioseismology.

Future Research Plan

With the confirmation that the p-mode amplitude peaks at the solar limb, combined with the discovery that the low-frequency solar background decreases at the limb, Toner has obtained sixty days of full-disk solar intensity images (recorded by the MDI instrumention board the SOHO spacecraft) which he will analyse to look for g-modes. Toner will continue to work on the image merge algorithm for GONG and adapt donated routines for the "local" analysis of GONG+ data. He also plans to investigate the phase relation between intensity and velocity oscillations locally on the Sun, rather than globally.


Toner performs observatory service as Assistant Data Scientist for the GONG project. He is also involved in the NOAO Educational Outreach Program, having given talks and demonstrations at schools and at Boy/Cub Scout functions.

Updated: 29Jun1999