Sihai network

Snow steamed bread in parking lot

A snow in April in Beijing before the Qingming Festival brought different scenery. Recently, a netizen photographed a wonderful snow scene. In Yanqing, a parking lot is lined with nearly a thousand round 'Snow buns'. According to the analysis, it is related to the surface temperature, the infiltration rate of brick land and land.

Why does the snow steamed bread appear in the parking lot? What's the matter? An April snow in Beijing brings a different view for the Qingming long holiday. In the afternoon of April 5, a snowscape video shot by a Yanqing netizen triggered a heated discussion among netizens. Different from other videos of mountains, rivers and trees after snow, the netizen found that in a parking lot, after the initial melting of snow, the formation of "snow buns" was very spectacular. Bian Yun, a meteorological engineer with the China Meteorological Administration, told Beijing Youth Daily that this situation should have something to do with the surface temperature and the different infiltration rates of brick land and land.

The reporter of Beiqing daily saw in the video that the square floor tiles were paved on the parking lot, and a white "steamed bread" shaped snow pile appeared on an empty parking space. After a rough calculation, there are nearly a thousand such "snow buns", which are arranged orderly and of similar size. Each snow pile is located in the center of a square brick.

Many netizens speculated that "snow steamed bread" is so neat and uniform, will it be made by people? Some netizens in Yanqing also explained that the square bricks in the parking lot are concave in the middle, exposing the land, and the snow falls on the bricks nearby quickly and slowly.

So why does snow melt at different rates on the floor tiles in the central depression? Bian Yun, a meteorological engineer from China Meteorological Administration, told Beiqing daily that there are two possibilities for this phenomenon, depending on the medium under the snow.

Bian said that when the cold air comes, the ground temperature will drop a little slower than the temperature, so the surface temperature of the ground or objects in contact with the ground will be slightly higher than the temperature, and the snow will be easier to melt. However, snow has a certain viscosity, so the snow falling in the middle of the hollow part of the square brick mainly contacts with the air, and the temperature can be stable below 0 ℃, which will be slower than the snow directly contacting the brick surface.

On the other hand, the temperature of brick surface rises faster than that of land, and the water permeability is higher. Just like when it rains, the brick ground dries faster than the land. When the snow melts, the brick surface is easier to seep water. At the same time, the temperature rises quickly, which is conducive to the melting of snow, so it will melt much faster. The water content of the land is high and the water infiltration rate is low, so the snow falls on the floor tiles of the land in the middle, which will turn more slowly, and finally form a raised 'Snow bread'.