We have the Advanced Composition Exporer (ACE), which orbits in the L1 libration point as a source for solar wind velocity and density (particles/cm^3) data. Typically, at a velocity in the range of 400 km/s, it takes about 4 days for solar wind changes to reach ACE. Measured solar wind velocities and densities tend to change from moment to moment. Official sunspot counts are obtained from Earth-based telescopes and change much more slowly.
From casual observation, there appears to be a positive correlation between solar wind velocity and density with sunspot count. Can anyone please gve me a reference that addresses this topic?
