Clouds might seem like a nuisance if you’re headed on a Sunday afternoon picnic. But put aside your personal biases for a second and consider this: Clouds can also tell the story of life on Earth.

That story has become a lot clearer thanks to new maps created by scientists that document a global year in the clouds in more intimate detail than ever before. The maps — a cloud atlas if you will — provide a fine-grained view of how clouds move around in our atmosphere and represent an important link between climate and ecological research. They’re also pretty easy on the eyes.

Seasonal cloud concentration by month. Darker colors indicate less of a seasonal trend in cloudiness.
Seasonal cloud concentration by month. Darker colors indicate less of a seasonal trend in cloudiness.EarthEnv

It turns out England is indeed cloudy for most of the year while most of the Bay Area’s clouds show up in February. Adam Wilson, a researcher at the University of Buffalo who helped create the cloud atlas, joked that you could use the maps to settle bets between friends on who lives in the cloudiest place.

But beyond bets and bragging rights, Wilson said the maps also provide a tool for tracking life around the planet. It turns out that the different biomes of the world, from deserts to mountains to cloud forests, all have their own special patterns of clouds: patterns that can be instrumental to studying the patterns of life itself.

“I wasn’t expecting the signal of the biomes would stand out so stark globally,” Wilson said. “The Mediterranean, southwest Africa, Australia, they all pop out as a totally different. That’s not scientifically amazing but seeing it for the first time in a map was just striking.”

Spatial variation in cloud frequency.
Spatial variation in cloud frequency.

There have been other efforts to get fine-grained cloud data in the past, but they’ve been marred by being limited to the tropics or getting false positives of clouds in snowy areas. Wilson and colleagues at Yale created a new analysis of satellite data captured at a one-kilometer resolution by NASA everyday for the past 15 years to shine a light on the cloudy skies.

The new data analysis helps bridge a big divide between the climate and ecology communities. Ecologists track plants and animals across the planet at a very fine scale, sometimes looking at a few square feet of soil, but climate science often provides data at a much larger spatial scale. With the new dataset, ecologists’ understanding of the climate factors that affect life has vastly expanded.