Affected by the strong cold cyclone, sand began to rise rapidly in the sand source area of ​​southern Mongolia, forming a large-scale strong sandstorm.

The main body of sand and dust moved rapidly to the southeast, affecting a large area of ​​northern my country.

　　The Beijing Municipal Meteorological Bureau announced yesterday that due to the impact of cold air and upstream sand and dust, there was a windy and dusty weather in Beijing at noon yesterday.

The PM10 concentration of some sites has increased significantly, and the hourly PM10 concentration exceeds 500 micrograms/m3, reaching the 6th serious pollution level.

　　According to China Weather News, data monitoring at 13:00 showed that gust winds in Yanqing, Changping, Mentougou, Haidian, and Shijingshan have reached levels 7 and 8, and visibility has dropped to 3 to 5 kilometers.

At 14 o'clock, there was a level 9 gale with a maximum wind speed of 22.1 m/s in Changping.

　　Statistics from China Weather Network show that from 2000 to 2020, the maximum wind speed in Beijing will reach level 9 for 15 days.

Among them, March is the most, with a total of 5 days; January 1 day, May 2 days, June 3 days, October 2 days, and December 2 days.

There are 147 days of strong wind at level 8.

　　According to forecasts, there will be northerly winds of magnitude 4 and 5 in Beijing from the night of the 6th to the 7th, and gusts of around 7; the evening and the first half of the 7th turn to southerly winds, and the wind will be reduced to 3 or 4; On the 8th, there were still 4 or so northerly winds during the day, with gusts of 7 and 8; on the 8th, the wind weakened at night and the gale weather process ended.

Doubt 1

Is there any dusty weather in Beijing in May?

Beijing's dusty weather is concentrated in March and April

　　Meteorological expert Zhang Mingying said that I remember that Beijing had dusty weather in May. "But in general, the dusty weather in May is still relatively small, mainly in March and April. After May, there will be a few days later. When it gets warmer, the vegetation on the surface grows; another, the wind is relatively less. Therefore, there are very few dusty weather in May."

　　Regarding the formation of this dusty weather, Zhang Mingying analyzed that, first of all, it was because of the relatively strong wind. In addition, some parts of Inner Mongolia had not fully grown grass, and there were some bare places that blew up after the wind passed.

"But the intensity was very weak, and the sandy weather process this time passed quickly."

Doubt 2

Why has there been frequent sand and dust since the beginning of this year?

Alternation of warm and cold air in winter and spring leads to frequent sand and dust

　　Everyone found that this year's sand and dust weather is a bit frequent. What is the reason?

Zhang Mingying introduced that Beijing's ecological environment is improving, and the sand and dust weather has been significantly reduced in recent years.

“In the 1970s and 1980s, and even before 2000, there were more sand and dust weather in Beijing or northern sand and dust. It is normal for more than a dozen or twenty times a year. In the past ten years, climate change and environmental governance It's more powerful, and the dusty weather is significantly reduced than before."

　　"This year’s situation is a little bit special. This year is mainly due to more wind and frequent air activity. When it is cold and warm, the surface will begin to thaw when it is warm, and then there will be cold air activity and wind blowing. So, this year Because the alternating between cold and warm is very frequent, and the wind is more frequent, the formation of sand and dust weather is more than in previous years." Zhang Mingying said.

Doubt 3

Can the dusty weather be cured?

Enhancing environmental governance can reduce the intensity and frequency of sand and dust

　　Zhang Mingying said that if the environment can be completely treated, the dusty weather can be eradicated.

"But we can't do this now. Environmental governance only plays a certain role. It can reduce the intensity and frequency of sand and dust, but the key is still the role of the atmosphere."

Zhang Mingying said, "Sand source areas are also difficult to manage. The Mongolian desert area is located in the upper reaches of northern China. When a northwest wind blows, sand and dust are easier to blow to the northern region."

　　But he believes that the governance of some places close to Beijing will play a certain role.

“The sand and dust from Mongolia, if there is no new sand and dust replenishment along the way, it will gradually sink to the ground and will not be transported over long distances. If the nearby places are better managed, the intensity of the sand and dust will be significantly weakened.”

■ Reminder

Beijing Municipal Commission of Housing and Urban-rural Development

The property should prompt the owner to inspect doors and windows

　　The Beijing Municipal Commission of Housing and Urban-rural Development issued a notice yesterday, reminding relevant property service companies and units to increase inspections, and promptly eliminate safety hazards in key locations such as building facades, building hanging objects and shelving objects, illegal construction, and garden tree protection; prompt owners to check in time Handle indoor doors and windows, glass, air-conditioning external machine parts, windowsills and other items such as flowers, and report to the local community neighborhood committee and property service unit in a timely manner.

Central Meteorological Observatory

Driving needs to increase the safety distance

　　The Central Meteorological Observatory reminded yesterday that you should avoid the "narrow tube effect" when you go out, and avoid the long narrow passages between tall buildings when you are walking or cycling; do not stay under old trees, billboards, and temporary structures, which are easy to fall off under strong winds. Cause harm; stay away from the embankment near the river, and try to avoid walking on the river bank or riverside in windy weather to prevent accidentally being blown into the water by the strong wind; increase the safety distance when driving, and bicycles, tricycles, motorcycles, etc. are affected by strong winds. Stability will deteriorate.

　　Beijing News reporter Li Yukun Xu Meihui and photographer Pu Feng