A new code for Fourier-Legendre analysis of large datasets: First results and a comparison with ring-diagram analysis

School of Mathematics & Statistics, University of Sheffield , Sheffield S3 7RH, UKReceived 2010 Sep 9, accepted 2010 Sep 13Published online 2010 Nov 11Key words Sun: helioseismology – Sun: oscillations – methods: data an alysisFourier-Legendre decomposition (FLD) of solar Doppler imaging data is a promising method to estimate the sub-surfacesolar meridional flow. FLD is sensible to low-degree oscillation modes and thus has the potential to probe the deepmeridional flow. We present a newly developed code to be used f or large scale FLD analysis of helioseismic data asprovided by the Global Oscillation Network Group (GONG), the Michelson Doppler Imager (MDI) instrument, and theupcoming Helioseismic and Magnetic Imager (HMI) instrument. First results obtained with the new code are qualitativelycomparable to those obtained from ring-diagram analyis of the same time series.

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