Wilting walls

A warming southern ocean bodes ill for the snows of Tateyama

Tateyama’s famous snow corridor opened to visitors on 15 April this year. As CNN reports, the centrepiece is half a kilometre of roadway excavated between snow walls that have sometimes towered up to a height of 20 metres. A tour bus provides scale in the brochure photos used to advertise this spectacle.

Image by courtesy of the Tateyama-Kurobe Alpine Route

A one-day excursion to this mountaintop might set you back as much as ¥30,000, even starting from nearby Nagano. But will the punters get what they pay for? In recent years, some have been disappointed. As one visitor reported on TrustPilot, “The irony was that, at the Murodo snow wall, the wall had melted such that it only came just above the top of the bus. Certainly not as impressive as the photos in the brochure indicated.”

The date and year of this comment – May 2016 – could be significant. Tateyama sits in one of the world’s snowiest regions, where the winter winds sweeping in from Siberia pick up moisture from the Japan Sea and dump it liberally on any mountain that stands in the way.

Even so, climate change is starting to bite. Seasonal snow accumulations in Japan were already shrinking a decade and more ago, except in northern Tohoku and Hokkaido. But the maximum snow depth in 2015/16 was the lowest in 16 years, say eight meteorologists who simulated the weather dynamics behind that exceptionally lean winter.

The dearth of snow in 2015/16 coincided with one of the most severe El Niño events – a warming of the equatorial Pacific Ocean – seen in a century. And, as the eight meteorologists conclude in their paper, “Analysis of the four largest El Niño events shows that warmer Aprils around Japan can be a typical response,” adding that yearly variations probably also played a role in the weak snowfall.

As it happens, the World Meteorological Organization recently warned that we may be heading into another El Niño phase, following three years of “an unusually stubborn and protracted La Niña”. So, if you want to see the Tateyama snow walls in their full glory – they are right now looming around 13 metres over the road – it may be wise to pony up that ¥30,000 soon, while La Niña still reigns.

References

Maggie Hiufu Wong, “On the ‘rooftop of Japan,’ a stunning 20-meter-deep snow corridor reopens to visitors”, CNN Travel, 14 April 2023.

Takahashi Hiroshi, “Long-term trends in snowfall characteristics and extremes in Japan from 1961 to 2012”, International Journal of Climatology, December 2020.

Hiroaki Kawase, Akira Yamazaki, Hajime Iida, Kazuma Aoki, Wataru Shimada, Hidetaka Sasaki, Akihiko Murata, Masaya Nosaka, “Simulation of Extremely Small Amounts of Snow Observed at High Elevations over the Japanese Northern Alps in the 2015/16 Winter”, Scientific Online Letters on the Atmosphere (SOLA), 2018, vol 14.

World Meteorological Organization, WMO Update, El Niño may return, 1 March 2023.