Original China Meteorological Administration.
Presently. The rain, snow and freezing weather entered the strongest stage.
The area of influence is wide, and the cumulative amount of rain and snow is large.
It lasts for a long time and has a large area of freezing rain.
*The Meteorological Observatory will be on February 4 at 10 a.m.
Orange alerts for freezing continue to be issued.
Henan, Anhui, Hubei, Hunan and other places.
There is rain, snow and freezing weather.
Many places appeared.
The phenomenon of rime, rime, and freezing rain.
It looks like it's all ice crystal tree hanging.
What's the difference?
Here comes the knowledge.
Rime. Rime refers to a layer of hard ice, usually transparent or ground-glass, that freezes immediately when supercooled raindrops hit the ground or ground objects near the freezing point. The rime is obviously different from the freezing of surface water, the rime is frozen while falling, and can immediately adhere to the surface of the bare object without loss, forming a thicker and thicker solid ice layer, so that the weight of the attached object increases, and when it develops to a certain extent, it will cause direct disasters and indirect hazards to the attached object.
Affected by the rain and snow weather process, at 9 o'clock on February 3, there was a rain rime in Shiqian County, Guizhou Province. Photo: Liu Engui.
The biggest hazard of rime is the interruption of power supply and communication lines. On snowy days, the steel towers of high-voltage wires are 2 to 3 times heavier than usual, but if there is rain on the wires, they may be 10 to 20 times heavier. After the wire is frozen, the cold shrinkage, coupled with the influence of the weight of the wind and the rain, can make the wire and the wire overwhelmed and broken, several kilometers or even dozens of kilometers of poles dumped in rows, resulting in power transmission, communication interruption, seriously affecting the local industrial and agricultural production and people's lives.
When the aircraft flies in the clouds with cold water droplets, the wings and propellers will accumulate ice, affecting the aerodynamic performance of the aircraft and causing a crash. Therefore, for the safety of winter flights, modern aircraft are basically equipped with de-icing equipment. When the rime is formed on the road, the road traffic will be blocked by the ice on the ground, and the traffic accidents will also increase, especially the ice on the mountain road is more dangerous, and it is often easy to make the car slide to the cliff, resulting in the destruction of the car and the death.
Because the ice is constantly freezing and thickening, it often breaks tree branches, so the rain rime can destroy young forests and frostbite fruit trees in a large area, causing serious losses to the forestry industry. Hard soil ice can also cause erosion of the crops that cover it, and if the wheat field freezes, it can freeze the winter wheat that has returned to green, or freeze the seedlings of crops sown in early spring. In addition, severe rain rime will also collapse the house, endangering people's lives and property.
Rime. Rime refers to the milky white ice crystals that directly condense water vapor in the air layer, or supercooled droplets directly freeze on the windward surface of ground objects. Rime is commonly known as tree hanging. The rime phenomenon is very common in the north of our country, and it is also common in the southern alpine areas, as long as there are cooling water droplets in the fog and meet a certain temperature. Usually the most susceptible to rime on mountain tops surrounded by supercooled clouds, it is also a common form of freezing on eaves, and can also form in cold weather near springs, rivers, lakes or ponds.
Beginning on the night of January 31, snowfall began in Yaozhou District, Tongchuan City, Shaanxi Province, forming rime. Photo: Zhang Xiao.
Rime is formed when supercooled droplets collide with an object that is also below the freezing temperature. At first, the water vapor in the air condenses into a solid state when it hits the object, forming a rime layer or rime deposit, which is composed of Xiaoice particles with pores between them, and then countless droplets below freezing point continue to accumulate freeze sticks on the rime layer with the wind, so as to form the typical white opaque appearance and granular structure of rime. Due to the rapid freezing of the individual supercooled water droplets, the cohesion between adjacent ice particles is poor and it is easy to fall off the attachment. Rime is a natural beauty that is universally appreciated, but it can sometimes become a natural disaster. Severe rime can sometimes break power lines and trees, causing damage.
Rime has certain benefits to the natural environment and human health. The decline of air quality in modern cities is a worrying problem, and rime is a natural "air humidifier" and "negative oxygen ion generator". Noise is a harmful by-product of modern urban life, rime has a certain noise cancellation ability, is the natural "silencer" of the environment. In addition, the moisture produced by the melting of the rime is beneficial for the overwintering crops in the north.
Sleet. Freezing rain is precipitation that consists of supercooled water droplets that freeze immediately after colliding with an object with a temperature below 0. Raindrops below 0 can remain supercooled in air with a temperature slightly below zero, and their appearance is the same as that of ordinary raindrops, and when it falls on an object with a temperature below zero, it immediately freezes into a smooth and transparent layer of ice, which is called rime.
On February 3, freezing rain occurred in Yueyang City, Hunan Province, and crystal clear "ice cubes" could be seen everywhere in the urban area, and the length of the "ice cubes" in the picture was about 5 centimeters. Photo: Wang Wei.
In addition, some people believe that freezing rain is a weather phenomenon seen in early winter or late winter and early spring. When the stronger cold air moves southward and encounters a warm and humid airflow, the cold air is inserted like a wedge below the warm air, and the temperature near the surface plummets below freezing, and the moist warm air is lifted and becomes a cloud to cause rain. When raindrops fall from the sky, a thin layer of crystal clear ice freezes on power poles, trees, vegetation and road surfaces due to the low temperature near the ground, which is called "freezing rain" in meteorology. Some areas in the south of our country call the freezing rain also called "ice ling", and the northern region calls it "earth oil" or "drift ice".
On the night of February 1, freezing rain occurred in Huoshan County, Anhui Province, and a thin layer of ice froze on the surface of the seats on the side of the road. Photo: Gao Lin.
Freezing rain is usually followed by a rime or rime landscape. Some people equate rime with freezing rain, but there is a difference between the two. Freezing rain is a special type of rainfall and weather phenomenon, whereas rime is the result of freezing rain and is a disaster or landscape.
Due to the differences in the formation mechanism and structure of rime and rime, the possibility and degree of disasters caused by the former are much higher than those of the latter. In high-latitude and high-altitude mountainous areas, rime is a frequent disastrous weather phenomenon. Rime is less dense and lightweight, and is much less destructive to power lines and trees than rime.
Guizhou is the region with the most freezing rain and rime in China, followed by Hunan, Hubei, Henan and Jiangnan provinces. The areas with more rime in the north are Shandong, Hebei, Liaodong Peninsula, Shaanxi and Gansu, among which there are more in the southeast of Gansu and Guanzhong in Shaanxi, among which there are more mountainous areas than plains, and the most high mountains; However, in Sichuan, Yunnan, Ningxia, Shanxi and the coastal areas of southern China, there are few rimes.
Original title: "Rime, rime, freezing rain can't be distinguished? Look at this