«Global mean time series of surface - and satellite - observed low - level and total cloud cover exhibit very large discrepancies, however, implying that artifacts exist in one or both data sets... The surface - observed low - level cloud cover time series averaged over the global ocean appears suspicious because it reports a very large 5 % - sky - cover increase between 1952 and 1997. (skepticalscience.com)
The controversial connection between cosmic rays, solar activity, and cloud cover is investigated using a climatological reconstructed reanalysis product: the North American Regional Reanalysis which provides high - resolution, low, mid-level, high, and total cloud cover data over a Lambert conformal conic projection permitting land / ocean discrimination. (swsc-journal.org)
In 1997, Svensmark claimed there was a correlation between cosmic ray intensity and satellite measurements of total cloud cover since the 1980s. (newscientist.com)