http://www.a-w-i-p.com/index.php/201...ffect-athmosph

"6. Conclusion

Our results show global scale evidence of conspicuous influences of
solar variability on cloudiness and aerosols. Irrespective of the
detailed mechanism, the loss of ions from the air during FDs reduces
the cloud liquid water content over the oceans. So marked is the
response to relatively small variations in the total ionization,
[that] we suspect that a large fraction of Earth’s clouds could be
controlled by ionization. Future work should estimate how large a
volume of the Earth’s atmosphere is involved in the ion process that
leads to the changes seen in CCN and its importance for the Earth’s
radiation budget. From solar activity to cosmic ray ionization to
aerosols and liquid-water clouds, a causal chain appears to operate on
a global scale."

David Christainsen