Large-scale horizontal flows in the solar photosphere. IV. On the vertical structure of large-scale horizontal flows

Abstract

In the recent papers, we introduced a method utilised to measure the flow field. The method is based on the tracking of supergranular structures. We did not precisely know, whether its results represent the flow field in the photosphere or in some sub-photospheric layers. In this paper, in combination with helioseismic data, we are able to estimate the depths in the solar convection envelope, where the detected large-scale flow field is well represented by the surface measurements. We got a clear answer to question what kind of structures we track in full-disc Dopplergrams. It seems that in the quiet Sun regions the supergranular structures are tracked, while in the regions with the magnetic field the structures of the magnetic field are dominant. This observation seems obvious, because the nature of Doppler structures is different in the magnetic regions and in the quiet Sun. We show that the large-scale flow detected by our method represents the motion of plasma in layers down to ~10 Mm. The supergranules may therefore be treated as the objects carried by the underlying large-scale velocity field.

8 pages, 5 figures, accepted in New Astronomy

References in corpus (4)

• Solar supergranulation as a wavelike phenomenon
• High-resolution mapping of flows in the solar interior: Fully consistent OLA inversion of helioseismic travel times
• Comparison of large-scale flows on the Sun measured by time-distance helioseismology and local correlation tracking technique
• Large-scale horizontal flows in the solar photosphere I: Method and tests on synthetic data

Cited by in corpus (7)

• Nucleosynthesis of light element isotopes in evolved stars experiencing extended mixing
• Tomography of plasma flows in the upper solar convection zone using time--distance inversion combining ridge and phase-speed filtering
• Structure and evolution of solar supergranulation using SDO/HMI data
• Issues with time--distance inversions for supergranular flows
• Large-scale horizontal flows in the solar photosphere V: Possible evidence for the disconnection of bi-polar sunspot groups from their magnetic roots
• Sub-Surface Meridional flow, Vorticity and the life time of Solar Active Regions
• Space-time segmentation method for study of the vertical structure and evolution of solar supergranulation from data provided by local helioseismology