The structure of the solar photospheric convection on granular and mesogranular scales

1Baran, OA, 1Stodilka, MI
1Astronomical Observatory of Ivan Franko National University of Lviv, Lviv, Ukraine
Kinemat. fiz. nebesnyh tel (Online) 2015, 31(2):21-33
Start Page: Solar Physics
Language: Ukrainian

We investigated the vertical structure of the photospheric convection of the Sun using neutral iron line λ ≈ 639.3 nm profiles taken around the centre of the solar disc in a non-perturbed region. The observations were obtained at the 70-cm German Vacuum Tower Telescope (Canary Islands, Spain) with high spatial resolution. The spatio-temporal variations of kinematic and thermodynamic parameters were reproduced by solving nonequilibrium inverse radiation transfer problem. Acoustic waves were removed by k-ω-filtration. We analyzed spatial variations of temperature, vertical velocity, density and gas pressure within convective cells of granular scales (0.5...5.0 Мm) and of mesogranular scales (5... 12 Мм) at different heights of the solar photosphere (h = 25...500 km). Extending to upper photosphere layers, the convective structure changes similarly at these scales: at the heights h = 200...250 km the temperature inversion takes place; the convective velocity inversion may occur at the same heights; at the heights h = 50...100 km the inversion of relative variations of density is found, the relative variations of density and pressure increase with heights and they become positive within ascending flows and negative in descending flows.

Keywords: photospheric convection, Sun, VTT telescope

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