Some of the same researchers who are predicting a
higher-than-average Sunspot Cycle 25 have also developed a "sun
clock" to help predict periods of high solar activity, including solar
flares and other events that can impact communications here on Earth. The ARRL
Letter reports that the group, led by Professor Sandra Chapman of the
Centre for Fusion, Space and Astrophysics at the University
of Warwick in England, used
the Hilbert transform to create a standardized map of a solar cycle. Their
research, according to a paper published in Geophysical Research Letters,
determined that transitions between quiet and active periods on the sun tend to
be quite sharp, and their "sun clock" can provide information on when
an active period may "switch on" or off.