Comparison of Solar Subsurface Velocities Using Small-Scale Ring Analysis, Time-Distance and Holography
Abstract
For the first time we compare subsurface horizontal velocity flows determined by all three common local helioseismic analysis methods on a very small scale (approximately 1-2 degrees). Holographic and time-distance techniques have been compared on small scales, however, ring analysis techniques have mainly been performed with 15 degree size tiles spaced 7.5 degrees apart. Here we use tiles approximately 2 degrees in size with a spacing of 1 degree and compare the results with those of time-distance and holography. All three techniques have been applied to full-disc Doppler velocity data with 4" resolution (0.2 deg at disc center) taken with the Michelson Doppler Imager instrument aboard SOHO during Carrington Rotation 1988 in March-April of 2002.
- Publication:
-
AGU Spring Meeting Abstracts
- Pub Date:
- May 2005
- Bibcode:
- 2005AGUSMSP24A..01H
- Keywords:
-
- 7522 Helioseismology