3. Relations to solar active phemomena
We find a pronounced recurrence of in all channels. This corresponds to a distinguished two sector structure of solar activity in 1994.
A comparison between sunspot numbers and sunspot areas confirms former results (see Fig. 3). In our time scales small activity corresponds to the maxima of solar irradiance. But this relation is not very pronounced. An anticorrelation with the 10.7 cm solar flux is much more distinguished (see also Fig. 3). Here a very good correspondence is to be found and a phase shift is suggested between both curves.
Finally we should mention the different behaviour of the infrared channel near 750 nm. In this spectral region we find a secondary minimum near April 27. One rotation before (near April 5) a small secondary minimum is also noticeable. This may be due to a stronger effect of chromospheric activity on this channel compared to the others. This spectral window is sensitive for three very strong CaII lines that are very sensitive to the solar plage activity. A more detailed analysis of this behaviour is planned.
© European Southern Observatory (ESO) 1997
Online publication: July 8, 1998