The Sun remains in a magnetic funk « Watts Up With That?

While sunspots are often cited as the main proxy indicator of solar activity, there is another indicator which I view as equally (if not more) important. The Average Planetary Magnetic index (Ap), the strength of which ties into Svensmark’s cosmic ray theory modulating Earth’s cloud cover. A weaker Ap would mean less cosmic rays are deflected by the solar magnetic field, and so the theory goes, more cosmic rays provide more seed nuclei for clouds in Earth’’s atmosphere. More clouds mean a greater albedo and less terrestrial solar radiation, which translates to lower temperatures.