The solar cycle, a period over which the sun’s polar fields flip, has been closely monitored since the 18th century, and is useful for understanding solar weather and its effects on technology on Earth and in space. Most specifically, predicting the amplitude and timing of the sun’s minima and maxima has become imperative for Earth’s satellite operators and power transmission grids.
There are several ways to measure solar activity. Counting sunspot numbers, measuring polar field strength, CME and coronal hole output, and radio flux emissions are some of the more tangible measurements which can be recorded from Earth and other spacecrafts.
Predictions for the maxima and minima of the solar cycle, which are heralded by a maximum or minimum number of sunspots observable on the sun’s surface, correlate with different types of space weather activity, high or low levels of atmospheric drag, and different weather patterns on Earth.
Currently, there exists a wide variety of predictions on the amplitude of Solar Cycle 25, which is expected to begin sometime before the end of this year. Some scientists believe Cycle 25 will have a higher amplitude than Cycle 24, which was the first lower amplitude cycle since the 1950’s. Others believe that Cycle 25 will follow Cycle 24 and decrease in amplitude, perhaps signalling the beginning of another Maunder Minimum.
The Solar Cycle 25 series released this week contains a dozen questions which will be used to help safely design satellites and monitor their movements in orbit, as well as inform electrical transmission operators about potential effects to grids and community power access.
The questions can be found here: