2017/09/20 by T. Oba, T. L. Riethmüller, S. K. Solanki +3 · 18 citations
Energy · Physics and Astronomy · #Adaptive optics and wavefront sensing #Amplitude #Convection #Convection zone #Deconvolution #Distortion (music) #Magnetic field #Photosphere #Scattering #Solar Thermal and Photovoltaic Systems #Solar and Space Plasma Dynamics #astro-ph.SR
paper · pdf · doi:10.3847/1538-4357/aa8e44
published in The Astrophysical Journal 849(1), 7 (IOP Publishing) · 32 pages, 13 figures, accepted for publication in ApJ
arxiv created 2017/09/20 · openalex created_date 2017/10/06 · openalex publication_date 2017/10/24 · arxiv updated 2017/11/01 · openalex updated_date 2026/08/06
Abstract Solar granules are bright patterns surrounded by dark channels, called intergranular lanes, in the solar photosphere and are a manifestation of overshooting convection. Observational studies generally find stronger upflows in granules and weaker downflows in intergranular lanes. This trend is, however, inconsistent with the results of numerical simulations in which downflows are stronger than upflows through the joint action of gravitational acceleration/deceleration and pressure gradients. One cause of this discrepancy is the image degradation caused by optical distortion and light diffraction and scattering that takes place in an imaging instrument. We apply a deconvolution technique to Hinode /SP data in an attempt to recover the original solar scene. Our results show a significant enhancement in both the convective upflows and downflows but particularly for the latter. After deconvolution, the up- and downflows reach maximum amplitudes of −3.0 km s −1 and +3.0 km s −1 at an average geometrical height of roughly 50 km, respectively. We found that the velocity distributions after deconvolution match those derived from numerical simulations. After deconvolution, the net LOS velocity averaged over the whole field of view lies close to zero as expected in a rough sense from mass balance.