Beijing experienced high winds, sand and dust, accompanied by reduced visibility and temperatures

The dust weather ended at night today, and the visibility improved

Since the beginning of this year, the largest sand and dust weather in the north has struck, and the windy sand and dust weather will sweep through North China, Northeast China and other places. Yesterday morning, the sand or floating dust has affected Xinjiang, Gansu, Inner Mongolia and other places, and Zhangye, Wuwei and other places in Gansu have encountered sandstorms. Then the main body of sand and dust continued to advance eastward.

Judging from the forecast map released by the Central Meteorological Observatory, Beijing was "fully covered" by this sand and dust weather. According to the staff of the Beijing Meteorological Bureau, the period when sand and dust mainly affects Beijing is from yesterday night to this morning, and the smell of earth will be smelled during the peak hour this morning. Yesterday, the Beijing Meteorological Observatory successively issued a blue warning for strong winds and a blue warning for sand and dust.

The high temperature and low precipitation in the first part of this year are the main reasons for the frequent occurrence of sand and dust weather in recent times. During dusty weather, the elderly, children and people with respiratory allergies should minimize going out, and wear masks for outdoor activities.

Many places in the north have suffered from sand and dust

The Central Meteorological Observatory continued to issue a yellow warning for sandstorms at 18 o'clock yesterday, affected by cold air and winds, it is expected that from 3 o'clock on March 21 to 20 o'clock on March 22, southern Xinjiang, northern Qinghai, central Gansu, Ningxia, most of Inner Mongolia, north-central Shaanxi, Shanxi, Hebei, Beijing, Tianjin, central and western Shandong, northern Henan, southwestern Heilongjiang, western Jilin, western Liaoning and other parts of the region have sand or floating dust weather, among which, there are sandstorms in central Inner Mongolia.

Xin Xin, a meteorological analyst of China Meteorological Channel, said that a Mongolian cyclone was formed on the 21st, and the cold front passed through Mongolia and China's sand source from the afternoon to the evening, and the sand may be very strong, and then it will advance to the southeast.

According to the sand and dust weather impact timetable released by China Weather Network, from yesterday afternoon to this morning, there were blowing sand or floating dust weather in parts of north-central Shaanxi, Shanxi, Hebei, Beijing, Tianjin, southwestern Heilongjiang, western Jilin, western Liaoning and other places, among which, there were sandstorms in the northerner areas of central and western Inner Mongolia, and strong sandstorms in local areas. Around noon today, sand and dust began to affect Henan, Shandong and other places. During the day on the 23rd, the sand and dust weather gradually weakened, and the impact tended to end.

With the invasion of sand and dust, there will also be significant winds and cooling weather in the north. Northeast Northeast China, Inner Mongolia, North China, Northeast China and other parts of the region have 4-6 northerly winds, gusts of 7-9, most of the above areas have 4-6 °C cooling, some areas cooling more than 10 °C.

Good water vapor conditions "mud rain" or again

Affected by cold air, from the night of March 3 to 21, there will be strong winds, sand, and dust in the Beijing area, accompanied by reduced visibility and temperature drops.

Du Jia, chief forecaster of the Beijing Meteorological Observatory, said that the wind began to blow in the middle of the night yesterday, and there were northerly winds of about 22 levels during the day on the 4nd, gusts of about 7 degrees, and up to 9 levels in the western mountains. From the night of the 22nd to the 23rd, there were still northerly winds of 3 and 4, and gusts of about 6.

Sand and dust come with strong winds, and sand and dust have also affected Beijing since yesterday night, and the minimum visibility during the day on the 22nd will drop to 2-4 kilometers. On the 22nd, the dust weather ended and the visibility improved.

Cold air is the "initiator" of this windy and dusty weather, and cold air also brings cooling. The Beijing Meteorological Observatory predicts that the temperature will gradually drop from the 22nd to the 25th, with the maximum daytime temperature dropping from 22°C on the 17nd to about 25°C on the 10th, and the lowest temperature during this period appearing at night on the 25th, which is about 0°C.

In addition, meteorological experts predict that the water vapor conditions in Beijing are good in the past two days, and there may be rain when the wind and dust blow, and the combination of rain and sand and dust will form "mud rain". Members of the public are advised to shelve their car wash plans until at least Thursday.

The reporter learned from the Beijing Municipal Ecological and Environmental Monitoring Center that PM3.22 is expected to be a level 2 good level on March 5, the primary pollutant will become PM2 throughout the day, and the air quality will be light to moderate pollution of grade 10-3, and the peak concentration is expected to reach the level of severe and above pollution in the second half of yesterday and this morning. In the afternoon, as the high pressure continues to move east and south, it is expected that the sand and dust influence process will end and the air quality will turn good.

■ Clarification

Why is Beijing prone to sand and dust in spring?

Peng Yingdeng, a researcher at the National Urban Environmental Pollution Control Technology Research Center, previously said in an interview that the period from March to May every year is the high incidence of sand and dust weather. In the spring, when the temperature rises, the surface soil thaws, but there is little rainfall, the surface vegetation has not fully recovered, and once the bare loose soil encounters strong winds, it will be swept up and dust, forming sandstorms and even sandstorms.

In addition to blowing up the dust in Beijing, every spring, Beijing is also vulnerable to the impact of sand and dust transported by Mongolia, Inner Mongolia, Northwest China and other regions, which is also the main source of sand and dust in Beijing. Mongolia desertification area is more, seasonal lack of rain is very serious, has been frequent dust weather, every year Mongolia half of the dust storms will affect China, in the northwest of our country arid areas, will also be the local fine particles of dust all the way in, evolved into high-intensity dust weather, the distance can reach thousands of kilometers.

From the historical data, the average number of dust days in March (3-1981, the same below) was 2010.2 days, the maximum was 4 days (12), and the maximum number of days since 1954 was 2000 days, which appeared in 9.

In addition, meteorological experts said that the temperature was high from late February to early March this year, resulting in the early melting time of snow in the sand source and the bare sand in advance; Precipitation began to fall low in mid-March, resulting in vegetation not growing. Under the combined influence, the surface sand is more exposed, and the sand will be picked up by a strong wind.

How to protect against dust weather?

How should people protect themselves from dusty weather? The National Health Commission has issued a reminder that in dusty weather, pollutants can directly cause different degrees of irritation symptoms or allergic reactions to the human body through mucosal tissues such as eyes, nose and throat and skin. Sand and dust particles can also enter the human body through the respiratory tract, causing a variety of respiratory diseases.

The elderly, children, pregnant women, people with respiratory diseases and cardiovascular diseases are sensitive groups. In dusty weather, sensitive people should avoid going out as much as possible, and seek medical attention as soon as possible if chronic cough with sputum or shortness of breath, episodic wheezing and chest pain occur.

When sand and dust weather occurs, residents should try to stay indoors, and the doors and windows can be closed to prevent sand and dust from entering the room; Mop the floor with a wet cloth and wipe with a wet rag to keep the room clean; Use humidifiers, sprinklers, etc. to keep the air humidity appropriate.

If you need to go out, you should pay attention to personal protection. Wear masks to reduce the damage caused by wind and sand to the respiratory tract, dust weather will have floating dust, inhalable particles and fine particles, wear N95 and above protective masks. Wear windproof glasses to avoid eye damage caused by wind and sand. Wear hats, scarves and other dust-proof equipment to avoid damage to the skin, hair, ears, etc. caused by wind and sand. When you go out, you should immediately wash your hands, wash your face, rinse your mouth with water, clean your nasal passages, take a bath if possible, and change your clothes in time to keep your body clean and comfortable.

Beijing News reporter Wang Jingxi Zhang Lu