[Robert A Cook PE]

However, when you look at the “clarity index” for 1960 through 2014, there is hardly a blip in actual atmosphere loss since 1964-65 (Guam), 1983, and then Pinatubo in the early 90’s.

Very, very abrupt and distinctive volcano impacts: but from this one!

Apparent Atmospheric Transmission of Solar Radiation at Mauna Loa, Hawaii

See: http://wattsupwiththat.com/reference-pages/solar/

And, from that source, the original from the NOAA Mauna Loa Lab:
http://www.esrl.noaa.gov/gmd/webdata/grad/mloapt/mlo_transmission.gif

[SunkenCiv]

Thanks RACPE.