Global Map showing Incidence of Fog

[Adelie]

Off and on for a while now I have been looking for a map that shows the incidence of fog, i.e. days of fog per year.

I have found one for the US in an old academic paper. Looking for one that covers the rest of the world.

Yes I have done a bunch of google searches. Don't know whether I am using the wrong search terms or what.

I know I can consolidate the info onto one map from the Atlas' of Pilot Charts, I'm just trying to save myself the work.