> And Gaia / sun activity perhaps why.
> Dave--could you get CME or at least sun spot activity for 1051-52?
I can help you with the latter, but not the former. You can get the
daily sunspot numbers for 1951 and 1952 here :
ftp://ftp.ngdc.noaa.gov/STP/SOLAR_DATA/SUNSPOT_NUMBERS/ . 1951 was
several years into the downside of the sunspot cycle, and the yearly
sunspot average for 1951 was 69.4 1952 was mere 31.5. That's not to
say, however, that there weren't any Coronal Mass Ejections. One of
the strongest solar flares ever observed was recorded in 1989, near
the bottom of the sunspot cycle. Aurora were spotted as far south as
the Carolinas, and power grids were crashed in Canada.
As far as CME's, scientists didn't even know there was such a thing
until they were observed by the Orbiting Solar Observatory satellite
in 1971. The solar corona had been observed during solar eclipses for
thousands of years, but it took the advent of the space age to