by F. Bosse & F. Vahrenbolt, June 22, 2019 in NoTricksZone
In May 2019 our sun was below-normal active again. The solar sunspot number (SSN) was 10.1, which is only 52% of the mean value in the evaluated cycle month no. 126 since the start of Cycle No. 24 began in December 2008.
It should be noted that the number of cycles that lasted this long is decreasing. In the previous month we reported on cycles 21, 18, 16, 15, 8 dropping out because they were shorter in total, and now SC 17 is getting added. Next month month SC 7 is will fall as well. The mean value thus becomes less meaningful as the end of the cycle approaches. But out of habit, we want to keep it nevertheless as comparison.
The activity in the past month was shifted very asymmetrically to the solar northern hemisphere, the southern hemisphere was spotless throughout the whole month. The solar north saw spots only on 15 days.
Fig. 2: Sunspot activity of the individual cycles since the beginning of cycle 1 in the year 1755. The numbers are computed by adding up the monthly differences of the observed cycles to the mean value, up to the current cycle month no. 126.