It's already the coldest time of the year, why aren't all the major ice rinks in Beijing open yet? Is this really a "warm winter"?

Review expert: Ye Haiying, deputy director of the New Media Center of the Meteorological Publicity and Science Popularization Center of the China Meteorological Administration (China Meteorological News Agency)

"Walking on the Ice on the 39th and 49th Days"

As winter progresses, people look forward to playing on the ice rink and enjoying the fun of skating.

Tourists are skating at the Beihai Park Ice Rink on February 4, 2024. Source: Beijing News However, this year, the major ice rinks in Beijing have not yet opened. Why is this? Is this really a warm winter?

PART. 1 Beijing's major ice rinks are not yet open

It is already the coldest time of the year, and most of the lake surface in Beijing's Shichahai Park is frozen, but there are still some areas that are not frozen.

Yang Qian, the person in charge of the Shichahai Ice Rink, said: "We are currently testing the ice twice a day. The thickest ice layer in the Houhai area of ​​Shichahai is about 11 centimeters, and the thinnest is about 5 centimeters. Judging from the current situation, the conditions for opening are not met."

So, what factors are affecting the opening of ice rinks? What standards must be met before an ice rink can be opened?

1. Basic conditions for opening ice rinks

The opening of the ice rink depends not only on the drop in temperature, but more importantly on the ice conditions of the lake or ice surface.

Yang Qian, the person in charge of the Shichahai Ice Rink, said that the ice surface thickness of the natural ice rink must reach 15 centimeters, and the temperature must remain between -8℃ and 1℃ for the next week before the ice rink can be opened.

Regular ice rinks such as outdoor artificial lakes and park lakes need to maintain low temperatures for more than half a month, so that the thickness of the ice layer on the lake surface reaches at least 15 cm to ensure the personal safety of skaters. Due to factors such as light and water depth, it is also necessary to select different locations for ice testing.

On January 15, 2024, at the Shichahai Ice Rink, two citizens enjoyed skating on the ice. Source: Beijing News

Liu Bosong, director of the business management section of the Old Summer Palace Administration, said that in the past three years, the ice rink has been open around December 30. This year, due to the high overall temperature in the early stage, the ice surface has not met the safety standards, so it has not been opened yet.

2. What is the standard for ice thickness at an ice rink?

Only when temperatures remain below freezing for several days can conditions be created for the ice layer to thicken.

According to calculations, when the ice thickness reaches 10 centimeters, adults can walk on the ice. However, if you want to carry out activities such as ice skating on rivers and lakes, the ice thickness of 10 centimeters still poses risks. Generally speaking, in order to ensure the safety of skaters, this standard is usually 15 centimeters. Only when the ice thickness reaches the standard and passes the inspection of relevant departments, the ice rink will be officially opened to the public.

3. How to measure the thickness of ice?

In fact, there are special ice surveyors at natural river and lake ice rinks. At different times of the day, they use professional ice picks to chisel the ice and select points where the ice layer is thinner for measurement.

When the ice is broken through, the ice surveyor inserts the ice hook into the hole and uses a vernier caliper to accurately measure the thickness of the ice. After the measurement, the ice surveyor will use the broken ice around the hole to fill the hole again to prevent it from cracking.

PART.2 Is this year really a warm winter?

The first reason many people think of for the delayed opening of major ice rinks in Beijing is probably "this year is a warm winter." So, is this year really a warm winter?

1. What is a “warm winter”?

A warm winter, as the name suggests, means a "warm winter", which means that the average temperature of a certain region in a certain year during the entire winter (winter nationwide is from December of the previous year to February of the following year) is higher than the normal value or the climate average. The normal value here is generally the average value of the past 30 years (the common meteorological value is from 1981 to 2010).

2. The warmest year

According to the latest monitoring information from the National Climate Center, China's annual average temperature in 2024 hit a historical high since meteorological observation records began.

Historical ranking of China's annual average temperature in 2024

The average temperature in most parts of my country ranks among the top three in history, among which the annual average temperatures in most parts of North China, the southern part of Northeast China, most parts of East China and Central China, the southwestern and eastern parts of Northwest China, the northern part of Southwest China and southeastern Tibet have reached historical highs.

So, based on the current climate forecast, can we determine that this year will be a warm winter?

3. It is not a “prediction concept”, but a post-concept “identification concept”

The assessment of a warm winter needs to be based on the average temperature of the three months of winter (December to February of the following year), which means that the answer can only be known after the end of winter. For example, the results of the judgment of whether the winter of 2023/2024 is warm or cold will not be announced until March 1, 2024.

We have now entered the "Three Nines" of winter. The temperature has dropped and some rivers and lakes have begun to freeze. The ice surface is not yet "solid" at this time, and there may be secrets beneath the ice. Please do not go on the ice without permission.