Time series of the noise obtained from the magnetograms of the point (pixel). The maximum value of the magnetic field strength was measured in the random point. The point was taken outside the active region 11166 (see Fig. 1, left panel). The area field-of-view is [100″ × 300″] including the active region. The point coordinates: [−230″    ×    200″] obtained at 20:00 UT on 2011 Mar. 07. Time series starts at 00:00:00 UT on 2011 Mar. 07. Solid-bold line shows the smoothed time series with a window of 2 h.