Hello, I'm interested in looking at long-term (100+ year) measures of magnetic storm sudden commencements and, also, coronal holes. Is there a convenient list of SSCs? Have coronal holes been measured in some way for long periods of time? I already know that I can, for example, look at the 27-day autocorrelation of geomagnetic activity, but something more directly related to the Sun would be appreciated.
Thank you.