Scientists Map Mount Fuji's Magical Clouds for First Time

For centuries, people have gazed in wonder at the distinctive clouds that crown Mount Fuji, but no one could explain exactly how they formed until now.

Researchers at the University of Tsukuba spent three years watching the iconic mountain through a dedicated network of live cameras, cataloging every cloud formation from January 2019 through December 2021. Their patient observation has finally cracked the code on three types of clouds that locals have known by name for generations: cap clouds, Tsurushi clouds, and Hata clouds.

The team discovered that each cloud type has its own personality and schedule. Cap clouds gently drape over the summit like a soft blanket, while Tsurushi clouds form elegant elliptical shapes that float nearby. The wispy, horse's mane style Hata clouds appear most often in winter.

What makes this research truly special is that it transforms folklore into science. These clouds have been part of Japanese culture for centuries, inspiring artists and photographers, but their formation remained a mystery cloaked in tradition and guesswork.

The scientists found that Tsurushi clouds form when mountain waves create vertical atmospheric oscillations, requiring specific conditions including weak wind shear and moisture at high altitudes. Hata clouds need completely different conditions, preferring winter weather with strong vertical wind shear and low-altitude moisture.

Why This Inspires

This study shows how modern technology can honor ancient observations while pushing understanding forward. The researchers didn't dismiss what local people had noticed for generations. Instead, they used cameras and careful measurement to validate that knowledge and build upon it.

Now scientists can predict when these beautiful formations will appear, helping photographers and visitors plan their trips. More importantly, understanding these unique cloud patterns helps meteorologists better comprehend how mountains influence weather systems worldwide.

Mount Fuji's clouds have captivated humanity for centuries, and now we finally understand the science behind their beauty.