How a city short on snow is hosting the Winter Olympic Games

Dry Beijing barely gets any snow, making this year's Winter Games the first to rely almost entirely on the man-made variety

At Yanqing north of Beijing, where organisers have built the alpine ski venue from scratch, the slopes stand out as ribbons of white contrasting starkly against the surrounding brown hillsides.

Snowmakers have also been deployed farther north in Zhangjiakou, which is hosting freestyle skiing, ski jumping and biathlon events.

All the sites are the result of months of snow-making using sophisticated European equipment.

Here's a closer look at the Olympic snow-making operation.

Natural snow is formed high up in the clouds when water vapour molecules cling to tiny particles like pollen or dust.

In scientific lingo, these specks are dubbed nucleators.

They create a snow nucleus that then attracts more water molecules to form snowflakes.

Snow-making equipment tries to duplicate this process by spraying atomised water into the air along with mechanically created nucleators — tiny ice crystals — which act as seeds for the manufactured snowflakes.

This process has been around for decades, with simulated snow first used at the 1980 Olympics in Lake Placid, New York.

TechnoAlpin won the bid to supply the Beijing Winter Games with snow-making equipment, a contract worth $22 million.

The Italian company has blanketed the slopes with 272 snow-making fan guns and another 82 stick «lances» to produce «technical snow» for the Winter Olympics skiing and snowboarding venues.

They're all hooked up to a system of high-pressure pumps and pipes that carry water that has been chilled by cooling towers up the slopes.

TechnoAlpin's fan guns resemble small jet engines or oversized hair dryers, with nozzles spraying either atomised water