Here are plots of total amount global time series and upper-level
amount global time series along with correlation maps. Upper-level amount
is the combined amount of mid+high clouds (the surface observations often
do not provide sufficient information to separately determine mid and high
amounts). I assume you will not be interested in low-level cloudiness
since that is probably more difficult to determine with IR channels.
Global upper-level cloud amount is decreasing over land and ocean, and most grid boxes
exhibit positive correlations. Global ocean total cloud amount appears to be possibly slightly
increasing and global land total cloud amount appears to be possibly slightly decreasing.
The ocean correlation map shows scattered positive and negative correlations, and the land
correlation map shows strong positive correlations over southwest Asia, Australia, and Africa.
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