The competition is just around the corner, and the Shougang ski jumping platform starts to make snow! Why use "ice snow"?

Introduction: Actually, the snow used in the competition does not depend on nature, but relies on funa technology.artificial snowHow to "mass production"? What is "ice snow"?
The 2023/2024 season International Snow Federation Single Board and Freestyle Ski Platform World Cup, hosted by the International Snow Federation and co-hosted by China Ski Association, Beijing Municipal Sports Bureau and Beijing Shijingshan District People’s Government, will be held in "Snow Flying", the ski platform of Shougang from November 30th to December 2nd.
On November 17th, the snow-making work of Shougang ski jumping platform was officially started. The snow-making work will last until November 27th. After the snow-making work is completed, athletes will be trained before the competition.
(Source: Beijing Evening News)
Snow quality is an important guarantee for ski jumping events. Because this year’s competition time is earlier than in previous years and the weather temperature is higher, the problem of snow making has attracted everyone’s attention.
Such worries are actually unnecessary. The development of snow-making technology is enough for China to realize "freedom of using snow".
Artificial snow is safer and more controllable.
Considering the uncertainty of natural weather process, especially snowfall, international events of snow sports generally use artificial snow to lay snow tracks. The reason is that, on the one hand, funa’s technology is artificially controllable, so it is not necessary to "rely on the sky to eat"; On the other hand, the threshold of this technology is relatively low-as long as the temperature is lower than 0℃, the snow machine can work.
"Usually, funa uses a’ snow cannon’ type snow machine. The principle of this machine is divided into two types. One is to use an ice-making device to produce a small piece of ice, and then use the piece of ice as raw material to make snow; The other is the traditional high-pressure water mixed with air to make snow. " Su Zhengjun, a senior engineer at the Weather Modification Center of China Meteorological Bureau, said.
The traditional artificial snow is to inject water into a special nozzle or spray gun, which uses high-pressure air to divide the water flow into tiny particles. When these water droplets meet the cold outside air, they will quickly solidify into ice crystals and become the well-known snowflakes before landing.
"Artificial snow takes a short time to form and grows fast, and the shape of snowflakes is basically the same. Snowfall in natural weather will have obvious changes in hardness the next day. " Su Zhengjun explained.
In the early morning, when the outdoor temperature is low, the natural snow usually has a high degree of solidification. At this time, the snow is hard, similar to "ice slag". Although this state of snow will make skiers reach a faster sliding speed, it also makes the snowboard’s grip on the ground poor. Especially for beginners, if the soft natural snow is not compacted, the snowboard is very easy to fall into the snow, causing accidents such as rollover and emergency stop.
▲ The smooth machine-pressed snow trail is also called "noodle snow" by fans, and skiing on the machine-pressed snow trail is compared to "eating noodles". The picture shows the snowy road of Changbai Mountain International Resort in Jilin (Source: Xinhua News Agency)
Create a "rubber runway" on the snow
It is easy to understand that artificial snow can help us get rid of our dependence on natural snowfall. So why do some winter sports tracks still use funa in areas with abundant snow and snowfall all the year round?
This has to mention another advantage of funa: customization. According to the needs of different events and different venues, artificial snow can freely adjust the particle size, water content and hardness of snowflakes.
For example, alpine skiing, as a traditional event in the Winter Olympics, has always been known as the "jewel in the crown of the Winter Olympics" because of its strong ornamental value, but the participants in this project are very fast (the top speed can reach 248 kilometers per hour) and the danger is very great, so the requirements for the track are more stringent. In order to build a snow trail that meets the international standards of alpine skiing, the snow used is not ordinary natural snow, but artificial "ice-like snow".
The so-called icy snow is used to describe a state of snow quality on ski resorts. In this state, the density of snowflakes is about 0.65 g/cm3, and the surface of the snow trail remains crystalline, just like a thin "ice shell", which is similar to the ice surface. This kind of snow trail has high hardness and is not easy to be destroyed. It can ensure that the surface of the snow trail is not deformed when the athletes turn at high speed. No matter which time the athletes play, the state of the snow trail is the same and relatively perfect.
▲ Competition-level snow trails are more dense and "more porcelain", sliding faster, but falling more painful (Source: "Chai Know" WeChat WeChat official account)
If icy snow is used to pave the pavement for alpine skiing, it is like building a "plastic track" in the snow, which can not only reduce the friction between the track surface and snowboards and significantly improve the athletes’ performance, but also improve the athletes’ comfort when skiing, protect their body joints and prolong their professional sports career as much as possible.
Shougang ski platform, using crushed ice to make snow.
The snow-making of Shougang ski jumping platform adopted the method of breaking ice to make snow. One side of the ice is crushed into snow powder by an ice crusher, and the snow powder is leveled and compacted by a snowmobile, and piled up from the bottom of the big platform from bottom to top, and the snowy road is paved. After the track is paved, the Xiang Xue surface will be sprayed with water and salt to form the final "ice-like snow" to ensure that the snow conditions of each athlete are basically the same when they slide.
Snow quality is an important guarantee for ski jumping events. "Ice snow" can not only improve athletes’ performance and ski comfort, but also protect athletes’ health. The team has many years’ experience and has served large-scale events such as the Winter Olympics. The team will also communicate with athletes on the quality of snow to satisfy their feelings.
Different from other temporary venues, Shougang ski platform, as the world’s first permanently reserved and used platform competition venue, can meet the load-bearing requirements of snowmobiles in track construction, which also creates a precedent for snowmobiles to lay snow trails on the platform.
(Source: Beijing Evening News)
Snow preservation and snow storage technology to ensure track quality
In fact, for a long time, building a high-quality ice-like snow track has been a technical difficulty in China’s ice and snow industry. In order to welcome the Beijing Winter Olympics and Paralympic Winter Games, researchers have made unremitting efforts to establish the territorial parameters for making ice-like snow in Yanqing and Zhangjiakou in Beijing. At the same time, with the help of complete snow-making techniques of water injection and compaction, qualified ice-like snow that meets the climatic conditions of continental monsoon region has been successfully made. Natural snowfall in winter in the local mountainous areas has become the "landscape snow" to decorate the Winter Olympic Games area.
In fact, for the high-standard Winter Olympics Road, natural snowfall is a "burden". If there is snowy weather, the soft natural snow will lead to the "mirror-smooth" icy snow track falling short. In addition, because Beijing Winter Olympics and Paralympic Winter Games are in the alternating period of winter and spring, they may encounter other extreme weather, such as sudden rain, which will cause thin ice on the track surface and increase the risks faced by athletes in the competition.
▲ On February 23, 2021, the staff of the National Alpine Ski Center in Yanqing Division ("Xuefeiyan") were inspecting and trimming the track (Source: Xinhua News Agency)
After the planning of scientific research personnel, if it is really "bad weather", the staff will immediately use the snow-pressing machine to re-compact the snow trail and carry out emergency finishing on the track. At the same time, in order to ensure the quality of the track, they will also use automatic measuring instruments such as ice and snow hardness tester and ice and snow particle size meter for quick detection, so as to effectively ensure the quality of snow and resume the normal race in the shortest time.
It is reported that in order to ensure sufficient snow during the competition, the 2022 Beijing Winter Olympics also made a bold attempt in snow storage: when the temperature is low in winter, make qualified snow in advance, and then store it in a flat site until the next year.
This seemingly impossible scheme has passed the feasibility test as early as 2017. The Beijing Winter Olympic Organizing Committee has successfully carried out the snow storage experiment in Yanqing Shi Jinglong Ski Resort. After the test of the following spring and summer, more than 60% of artificial snow was successfully stored.
Related reading:
How many steps does it take to build an icy snow track?
Building an international and high-level ice-like snow track for Olympic events is not only due to the snow machine. At present, the icy snow track can be divided into two categories: racing track and competitive track. Take the ice-covered snow racing track as an example;
First, the snowmobile needs to open the snow trail, break the snow blocks and loosen the snow surface;According to the location of the track and the temperature at that time, inject water into the snow-only in this way can we ensure that the track has a certain strength and enough elasticity;The embryonic form of an icy snow track is basically formed by constantly turning over the wet snow and pressing it evenly again and again.
▲ Different from the watering method of the racing track, the competitive track adopts the "Z-shaped water injector" water injection method (Source: Beijing Daily)
After that, the staff should ensure that the thickness of the ice-like snow layer is consistent, and there are no big holes in the snowy road. After confirming that everything is correct, flatten the track and let the snow layer form a shiny "ice shell" from bottom to top;After completing all the steps, the staff also need to clean up the floating snow on the track.At this point, a qualified "mirror-like" icy snow track can be put into use.
Author/Reporter Wang Xueying
Editor/Ding Lin New Media Editor/Fang Yongzhen
Interview experts:
Su Zhengjun (Senior Engineer, Weather Modification Center, China Meteorological Bureau)
Source: Beijing Science and Technology News, part of which is integrated with Beijing Evening News.
Reporting/feedback

Baseball home runs are increasing or partly due to global warming.

In recent years, the number of home runs in American baseball games has increased obviously, which is rumored by baseball circles to be related to the rising temperature. American researchers recently used data to speak, confirming that this statement has some truth. They estimate that global warming has helped major league baseball batters hit an average of about 50 more home runs each year.

Home run refers to the attack method that the batter runs through the first, second and third bases in turn and returns to home plate safely after hitting the ball from the other side. It is a very wonderful climax moment in the baseball game. According to NBC, from the beginning of American professional baseball in the late 19th century to 1993, there was only one season when each team hit more than one home run per game. Since 1994, only four seasons have not seen such a "grand occasion". In the history of professional baseball league, the top four seasons of home runs all appeared in 2017 and later years.

Researchers at Dartmouth College in the United States said in a peer-reviewed paper published in the latest issue of Bulletin of American Meteorological Society that they analyzed 100,000 games and more than 200,000 balls played by Major League Baseball from 2010 to 2019, and combined with weather conditions, stadium and other factors, they found that the probability of hitting a home run increased by 1.8% when the temperature rose by 1 degree Celsius.

According to data from the National Oceanic and Atmospheric Administration, the average temperature in June, July and August in the United States has increased by 1.1 degrees Celsius in the past 40 years.

According to researchers, the physics behind the relationship between temperature and home run is simple: when the temperature rises, molecules move faster and farther away from each other, thus reducing the air density, reducing the flying resistance of baseball and making it fly farther.

However, according to researchers’ estimates, from 2010 to 2019, climate warming made about 500 home runs, accounting for only 1% of all home runs. In contrast, non-climatic factors have a greater impact. Allen Nathan, a physicist at the University of Illinois, believes that the biggest factors are the ball itself and the stitching, as well as the batter’s physical quality, pitching angle and speed.

The researchers found that the impact of climate warming on home runs also varies from venue to venue. Home runs are more likely to occur in outdoor venues during the day than in dome stadiums where games are held at night.

The researchers also established a model to estimate the impact of different degrees of warming on home runs. Under the worst-case scenario, by 2050, there will be about 192 home runs in the United States every year, and by 2100, the number will increase to about 467. In a milder situation closer to the current climate change, by 2050, climate warming will promote about 155 home runs every year, and by 2100, this number will increase to about 255.

Source: CCTV news client