Another sign of increased solar activity is being reported by
spaceweather.com - a decrease in stratospheric cosmic ray levels that appear to be inversely proportional to solar activity. Nearly every week for the past six years, staff at the website, working with students from Earth to Sky Calculus, have been sending weather balloons equipped with radiation sensors into the upper stratosphere to measure cosmic ray levels. Those levels peaked at the solar minimum in late 2019 and have been decreasing ever since.
Spaceweather's Dr. Tony Phillips explains that the radiation comes from deep space and has to fight its way through the sun's magnetic field in order to reach the Earth. That field weakens during the declining years of each solar cycle and strengthens as solar activity increases. The stronger the sun's magnetic field, the fewer cosmic ray particles are able to break through. A graph of the cosmic ray measurements is available on the spaceweather.com website.
