1. 1 Mode Parameter Variations from GONG Ring Diagrams: An Update Rachel Howe, NSO

2. 2 Synopsis Lots of Data! Frequency shifts Power maps and amplitude shifts Summary

3. 3 Lots of Data We now have about 30 Carrington Rotations of GONG+ data analyzed, contiguous from 1980-2004 and then 2008-2012. 605 days, 114,345 dense-pack cubes. That’s 12Tb of data in the tracked velocity cubes. About 2.5Gb just in parameter tables.

4. 4 Frequency Shifts One rotation, after subtraction of geometric terms, for l=652, n=3

5. 5 Frequency shifts, 25 rotations

6. 6 Frequency variations from 25 rotations

7. 7 A thought Availability of frequencies for many rotations should allow detailed study of effect of active region evolution on local sound speed profile.

8. 8 Parameter sensitivity to B, by rotation Linear (left) and quadratic (right) coefficients for fits of frequency (top), and amplitude (bottom) against B. Colored ribbons correspond to different n. B from MDI daily synoptic images. Amplitude sensitivity seems to vary from rotation to rotation.

9. 9 Power Maps Take each tracked merged image (MI) data cube. Perform temporal FFT for each spatial pixel. Write 4-plane FITS file containing low-frequency (0.5 < < 1.5 mHz), 5-minute (1.5 < < 5.5 mHz) and high-frequency (5.5 < <7.5 mHz) total power, and mean velocity. Gzipped file is 0.25Mb for each dense cube.

10. 10 Power Maps Mosaic for one day (patches normalized separately: apparent gradient is artifact of overlap order). Take mean for each patch … and subtract fit to distance from disk center.

11. 11 Geometric Term in Amplitude Power vs distance from disk center, from rings (left) and power maps (right). Slope does not look constant.

12. 12 Slope of power against , from ring diagram fits. Possible correlation with apparent radius? Time (days) Or with B?

13. 13 Summary GONG data are now plentiful! Power maps will be available. 5-minute power scaling not completely understood. –Ideas welcome. Stay tuned!