Government officials from Jilin City, in northeast
China's Jilin
Province, are using a special frost that has increasingly
appeared on its trees since the building of a dam in 1942 to
promote winter tourism.
They told a press conference in Beijing yesterday
that, though the frost could not be guaranteed to appear everyday
in winter, the frequency was high and predicted in daily morning
forecasts.
After the Fengman Hydropower Station dam was built
on the upper reaches of the Songhua River, the friction as it
passes through the hot turbines keeps the water just warm enough to
stop it from freezing more than 60 kilometers downstream, even in
the bitterly cold winter.
In Jilin's winters, temperatures often drop to
minus 20 Celsius degrees, turning other waterways into skating
rinks. But on the Songhua, the temperature difference between the
water and the air makes heavy white vapor rise.
If the vapor density, air pressure and wind speeds
are within range, icy droplets freeze on the surface of tree
branches along the riverbank, creating what to some look like
crystalline, snow-white flowers.
Sun Yaoqian, a municipal government official, said
that from December 15, 2004 to February 18 this year there were 38
days when the frost could be seen on Jilin's Wusong Island, and
even in the city proper 11 such days were reported.
Every midnight, information is collected from sites
around Jilin to produce the daily morning forecasts, available from
the local weather authority (0432-4662724), tourist sites, radio
(0432-4681053) and hotels.
Because the factors involved are complex, the
forecasts can only be made on the same day.
Jilin, formerly called "Jilin Wula" (which means
"along the river" in the Manchu language), is the second largest
city of Jilin Province and is 1,100 kilometers from Beijing.
(China.org.cn by Wang Zhiyong, December 16,
2005)
