Preliminary study of the evolution of solar magnetic structures and photospheric horizontal velocity fields Original Research Article

In October 1997, we made a coordinated observation of the solar photosphere and chromosphere at Hida observatory (Kyoto university, Japan) and at Teide observatory (Tenerife) over a 10 day. We obtained imaging data series continuously during 6 hr 45 min in G-band (4308 Å) observed with the Domeless Solar Telescope (DST) at Hida on 24th October (effective FOV; 96″×99″). Additionally, in this observation, we simultaneously observed image series of the chromosphere during the latter 4 hr 10 min in H α line center and H α ±0.6 Å. From these data set, we could detect that emerging flux tubes crossed the photosphere to the chromosphere and that ‘convective collapse’ phenomena appeared at the stage of the spot formation. Moreover, we confirmed that the lifetime of mesogranulation was about 4000 sec (70 min) from the temporal evolution of velocity patterns. We show here only a summary of these observations.