As 2018 comes to an end, Solar Minimum appears to be just getting started. Cosmic rays could continue to increase for years to come, so stay tuned.
So you thought Solar Minimum was boring? Think again. High-altitude balloon flights conducted by Spaceweather.com and Earth to Sky Calculus show that atmospheric radiation is intensifying from coast to coast over the USA–an ironic result of low solar activity. Take a look at the data:
Since 2015, we have been monitoring X-rays, gamma-rays and neutrons in the stratosphere – mainly over central California, but also in a dozen other states (NV, OR, WA, ID, WY, KS, NE, MO, IL, ME, NH, VT). Everywhere we have been there is an upward trend in radiation – ranging from +20% in central California to +33% in Maine. The latest points, circled in red, were gathered during a ballooning campaign in August-October 2018.
How does Solar Minimum boost radiation? The answer lies in the yin-yang relationship between cosmic rays and solar activity. Cosmic rays are the subatomic debris of exploding stars and other violent events. They come at us from all directions, 24/7. Normally, the sun’s magnetic field and solar wind hold cosmic rays at bay – but during Solar Minimum these defenses weaken. Deep-space radiation surges into the solar system.
Cosmic rays crashing into our planet’s atmosphere produce a spray of secondary particles and photons. That secondary spray is what we measure. Each balloon flight, which typically reaches an altitude greater than 100,00o feet, gives us a complete profile of radiation from ground level to the stratosphere. Our sensors sample energies between 10 keV and 20 MeV, spanning the range of medical X-ray machines, airport security devices, and “killer electrons” in Earth’s radiation belts.