Bulletin of Taras Shevchenko National University of Kyiv. Astronomy, no. 51, p. 25-27 (2014)

The observed evolution of convective flows in the solar photosphere (velocity field)

O. Baran, engineer,
M. Stodilka, Dr. Phys. and Math. Sciences
Astronomical Observatory of Ivan Franko National University of L’viv

We investigate the evolution of the vertical velocity field by solving the inverse problem of nonequilibrium radiative transfer using neutral iron lineλ≈639.3nm profiles. The profiles were taken with high spatial resolution around the centre of the solar disc in the non-perturbed region. The acoustic waves were removed by k-ω filtration. We analyze the spatial variations of vertical velocity at different heights of the solar photosphere (h=-25÷550km): the correlation coefficient of velocities at different heights with velocities at h=0km is significantly reduced in the upper photosphere; at heights h>200km the velocity inversion is detected for 12% of convective cells (granules and intergranules). We found that upflows usually arise in the lower photosphere and eventually perturbation extends upwards; downflows mostly originate in the upper layers of the photosphere and later the perturbation region goes down.

Photosphere, convection, vertical velocity

Baran, O. A. 2011, Advances in Astronomy and Space Physics, 53
Stodіlka, M.І. 2002, ZHurnal fіzichnih doslіdzhen’, 6,4, 435
Stodilka, M.I., Baran, O.A., Malinich, S. Z. 2006, Kinem. i fiz. nebesn. tel, 22, 3, 173
Stodilka M. I., Baran O. A. 2008, Kinem. i fiz. nebes. tel, 24, 2, 99
Espagnet, O., Muller, R.,Roudier, T., Mein, P., Mein, N. 1995, Astron. Astrophys., Suppl. Ser.,109, 1, 79
Gadun, A. S., Solanki, S. K., Johannesson, A. 1999, Astron. and Astrophys.,350, 2, 1018
Hirzberger, J.,Bonet, J. A.,Va’zquez, M.,Hanslmeier, A. 1999, Astrophys. J.515,1, 441
Kostyk, R. I.,Shchukina, N. G. 2004, Astronomy Reports.,48, 9, 769
Kostik, R., Khomenko, E.,Shchukina, N. 2009, Astron. Astrophys., 506,3, 1405
Nordlund, A., Stein, R. F.,Asplund, M. 2009, Liv. Rev. Solar Phys., 6, 2, 117
Ploner, S.R.O., Solanki, S.K., Gadun, A.S. 1999, Astron. Astrophys., 352, 2, 679
Puschmann, K., Vazquez, M., Bonet, J. A., Ruiz Cobo, B., Hanslmeier, A. 2003, Astron. Astrophys., 407, 1, 363
Puschmann, K., Ruiz Cobo, B., Vazquez, M.,Bonet, J. A.,Hanslmeier, A. 2005, Astron. Astrophys.,441, 3, 1157
Vernazza, J. E., Avrett, E. H., Loeser, R. 1981, Astrophys. J. Suppl. Ser.,45, 635

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