Comparison of large-scale flows on the Sun measured by time-distance helioseismology and local correlation tracking technique

Abstract

We present a direct comparison between two different techniques time-distance helioseismology and a local correlation tracking method for measuring mass flows in the solar photosphere and in a near-surface layer: We applied both methods to the same dataset (MDI high-cadence Dopplergrams covering almost the entire Carrington rotation 1974) and compared the results. We found that after necessary corrections, the vector flow fields obtained by these techniques are very similar. The median difference between directions of corresponding vectors is 24 degrees, and the correlation coefficients of the results for mean zonal and meridional flows are 0.98 and 0.88 respectively. The largest discrepancies are found in areas of small velocities where the inaccuracies of the computed vectors play a significant role. The good agreement of these two methods increases confidence in the reliability of large-scale synoptic maps obtained by them.

arXiv comment14 pages, 6 figures, just before acceptance in Solar Physics

References in corpus (4)

• Solar supergranulation as a wavelike phenomenon
• Validation of Time-Distance Helioseismology by Use of Realistic Simulations of Solar Convection
• Local helioseismology and correlation tracking analysis of surface structures in realistic simulations of solar convection
• Large-scale horizontal flows in the solar photosphere I: Method and tests on synthetic data

Cited by in corpus (23)

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• An exploration of heating mechanisms in a supra-arcade plasma sheet formed after a coronal mass ejection
• Helioseismic Holography of Simulated Solar Convection and Prospects for the Detection of Small-Scale Subsurface Flows
• Comparison of solar surface flows inferred from time--distance helioseismology and coherent structure tracking using HMI/SDO observations
• Measuring solar active region inflows with local correlation tracking of granulation
• Large-scale horizontal flows in the solar photosphere III: Effects on filament destabilization
• Physical Origin of Differences among various Measures of Solar Meridional Circulation
• Analysis of Flows Inside Quiescent Prominences as Captured by Hinode/Solar Optical Telescope
• The shrinking Sun: a systematic error in local correlation tracking of solar granulation
• Large-scale horizontal flows in the solar photosphere II: Long-term behaviour and magnetic activity response
• Data compression for local correlation tracking of solar granulation
• Issues with time--distance inversions for supergranular flows
• Theory of Solar Meridional Circulation at High Latitudes
• Reconstruction of Solar Subsurfaces by Local Helioseismology
• Large-scale horizontal flows in the solar photosphere. IV. On the vertical structure of large-scale horizontal flows
• Horizontal Flows in Active Regions from Ring-diagram and Local Correlation Tracking Methods
• Average solar active region: I. Intensities, velocities, and the photospheric magnetic field
• Observational characterisation of large-scale transport and horizontal turbulent diffusivity in the quiet Sun
• Meridional Circulation From Differential Rotation in an Adiabatically Stratified Solar/Stellar Convection Zone
• Evolution of solar surface inflows around emerging active regions