Sunspots, Space Weather, and the Earth

Prikryl et al 2009: Solar magnetic sector boundary passage (SBP) and vorticity area index (VAI), by weather reconstruction ERA-40 dataset back to 1963-2002, confirmed the "Wilcox effect". The interplanetary magnetic field and associated "space weather" directly effect Earth's weather.

News from Dr. Leif Svalgaard at Stanford:

Wolf was right...we can use magnetic field strength to calibrate solar irradiance. The correlation between solar far-UV radiation and geomagnetic force on the Earth's surface is extremely good;

now we have an objective calibration for sunspot number.
The conclusion? Leif 2007 finds no long-term trend in solar irradience from at least 1600. through the present.