Global cloudiness. I have always wondered where on earth am I the most likely to get depressed from lack of sunshine.
I made this image of the average number of cloudy days per year picked up by the Advanced Very High Resolution Radiometer (AVHRR). Dark blue areas have nearly 365 cloudy days, while light tan areas have hardly any.
It is amazing how you can pick up continental boundaries and even major rivers purely from cloud frequency alone. Looks like Gabon and Singapore are some of the gloomiest places to live.
For other examples check out this Instagram page.