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Astron. Astrophys. 353, 389-395 (2000)

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Small-scale topology of solar atmosphere dynamics

IV. On the relation of photospheric oscillations to meso-scale flows

Nick M. Hoekzema and Peter N. Brandt

Kiepenheuer-Institut für Sonnenphysik, Schöneckstrasse 6, 79104 Freiburg Br., Germany

Received 17 May 1999 / Accepted 14 October 1999


We use a high quality five-hour sequence of images of the solar photosphere taken at the Swedish Solar Vacuum Telescope, La Palma, to study the relation of meso-scale divergence with the amplitudes of photospheric intensity oscillations. Meso-scale flows are determined by local correlation tracking of the granulation. Statistical evaluation of the co-location probability of regions with more than twice the average oscillation amplitude and regions with high or low meso-scale divergence shows that high amplitude regions are preferentially located in regions of negative divergence (convergence) and avoid meso-divergent regions. Additionally we confirm the increase of granule brightness in regions of positive divergence with the opposite effect in regions of convergence.

Key words: Sun: granulation – Sun: oscillations – Sun: photosphere

Send offprint requests to: P.N. Brandt (pnb@kis.uni-freiburg.de)

© European Southern Observatory (ESO) 2000

Online publication: December 8, 1999