Forbush Decrease, what is it?

A Forbush decrease is a rapid decrease in the observed galactic cosmic ray intensity following a coronal mass ejection (CME). It occurs due to the magnetic field of the plasma solar wind sweeping some of the galactic cosmic rays away from Earth. During a energetic explosion of Xclass these forbush GCRs can be caught on ground based stations.

Interesting? Then read on, each bold blue is a link.

https://astronomy.swin.edu.au/cosmos/f/Forbush+Decrease