Author: Lang Lang

  When my eyes are closed and opened, the sky is "yellow" again, I know, "it" is coming...

Image source: Weibo@中国天气

  Affected by the Mongolian cyclone, the dusty weather has "returned".

  The sand and dust weather process will affect more than ten provinces, autonomous regions and municipalities, affecting an area of ​​nearly 3 million square kilometers, and the intensity may reach the level of sandstorms.

On the 29th, sand and dust weather may affect the line along the Huaihe River.

  Flight cancellations, pollution exploded... Strong sand and dust in many parts of the north

  On the afternoon of March 27, the impact of sand and dust was already felt in many places.

  Sandstorms occurred in Xilin Gol, Chifeng, Inner Mongolia and other places. Under the influence of the sand and dust weather, several flights from Hohhot to Xilinhot were delayed or cancelled.

  Monitoring showed that around 23:00 on the 27th, PM10 in Hohhot, Inner Mongolia, exceeded 9,000 micrograms/m3, and PM10 at the Kangbao site in Zhangjiakou, Hebei exceeded 5,000.

The picture shows the air quality diagram in Beijing as of 10:00 on the 28th

  According to news from the Beijing Municipal Ecological Environment Monitoring Center, under the influence of the northwest wind, sand and dust covered the entire city at 07:00 on the 28th, and the average concentration of PM10 in the city at 07:00 was over 2000 micrograms per cubic meter, which is a level 6 serious air pollution.

On March 28, strong winds and sandstorms occurred in Beijing. This is the second sandstorm that Beijing has encountered since March.

Photo by Li Peiyun, reporter of China News Service

  At present, the air quality in Beijing has reached the highest level of serious pollution.

It is expected that the daytime on the 28th will still be the main period of the impact of the sand and dust process on Beijing's air quality. PM10 will be at a high concentration level, which is a level 6 serious pollution; the impact of sand and dust on the air quality of Beijing at night on the 28th will gradually weaken.

National sand and dust weather forecast map (08:29, March 28-08: 00, March 28)

  More than ten provinces will be affected by sand and dust as far as the Jianghuai line

  The wide range of impact, long duration, and strong sand dust intensity are the characteristics of the sand and dust weather process summarized by meteorological experts.

  The Central Meteorological Observatory continued to issue a yellow dust storm warning at 06:00 on March 28. It is estimated that under the influence of cold air and gale, it is expected that Xinjiang, Qinghai, Inner Mongolia, Gansu, Ningxia, Shaanxi, Shanxi, Hebei, Beijing, Tianjin, Henan will be affected during the day on March 28. , Shandong, Central Liaoning, Jilin, Heilongjiang and other places have blowing sand or floating dust.

  Among them, there were sandstorms in parts of central and southeastern Inner Mongolia, northwestern Shanxi, central and northern Hebei, Beijing, Tianjin, and western Liaoning. There were strong sandstorms in the south and southeast of central Inner Mongolia.

On March 28, strong winds and sandstorms occurred in Beijing. This is the second sandstorm that Beijing has encountered since March.

Photo by Li Peiyun, reporter of China News Service

  From the 29th to the 30th, it is expected that the main body of sand and dust will leave the country via Northeast my country. The remaining sand and dust in North China will continue to be affected by the continued weak northerly wind and continue to move south to affect Shandong and most parts of Henan.

  Obstructed by large-scale precipitation in the middle and lower reaches of the Yangtze River on the 29th, the sand and dust transmission process is expected to stop as far as northern Hubei, Anhui and central Jiangsu.

  For example, in Beijing, the period of strong sand and dust is from morning to night on the 28th, lasting more than 12 hours, which is equivalent to the duration of sand and dust on the 15th.

The Beijing Municipal Meteorological Bureau initiated a Class IV emergency response to meteorological disasters (sand dust) at 11:30 on March 27. The yellow warning signal for sand and dust storms and the blue warning signal for strong winds are in effect.

  Why are sand and dust weather frequent recently?

  Recently, the feeling of presence is frequently brushed in sand and dust weather. What is the reason for such frequent sand and dust weather this year?

As monitored by the National Climate Center, since March this year, Mongolia and the western part of Inner Mongolia have been warming up significantly. The temperature is 2-6°C higher than in previous years, and the precipitation is significantly lower than normal (the orange area indicated by the arrow).

This caused the snow to melt in advance and the sand source was exposed. At the same time, the vegetation had not yet grown.

The Gaofen-1 satellite monitoring image shows that there is almost no obvious snow on the ground, no vegetation cover, and bare sand. Source: China Weather Network

  As the temperature rises, the snow in the sandy source area is rapidly decreasing.

Judging from the images of the Sino-Mongolian border and Mongolia’s East Gobi Province taken by the Gaofen-1 satellite on March 24, there is no exposed sand source covered by snow.

  Meteorological experts said that since the surface is basically free of snow cover, the large-scale bare surface provides sand source conditions for the spring dust weather.

At the same time, the temperature in the north has risen significantly, and the ground is dry, which is conducive to sand formation.

FY-4A meteorological satellite sand and dust monitoring animation (pink is sand and dust)

  When the last round of sand and dust weather arrived, Zhang Bihui, director of the Environmental Meteorological Center of China Meteorological Administration, once said that such dust weather would not become normal.

At a press conference held by the Beijing Meteorological Bureau on the 27th, Wang Ji, director of the Beijing Climate Center, also said that this kind of sand and dust weather is not common. On the whole, the sand and dust showed a downward trend year by year.

  Data from the National Climate Center show that since 1961, the average number of dust days and dust storm days in the northern part of my country has decreased significantly. Since 2000, the frequency of spring dust and dust storms in northern China has also been lower than that of the same period in normal years.

  The dusty weather in April is still active

  Once upon a time, it was not uncommon for Beijing to have dusty weather in spring. In March, the average number of dusty days in Beijing was 3.6 days.

  However, in recent years, due to China's vigorous efforts to prevent sand afforestation and actively manage the ecological environment, the dust weather in Beijing has become less and less.

Compared with the 1960s and 1970s, the number of dust days in Beijing has decreased by 70%, and the intensity has been significantly weakened.

  From the perennial data statistics, after March every year, sand and dust weather in northern my country also enters a period of high incidence.

In spring, the temperature rises rapidly, and the northern sand sources begin to thaw. In addition, the frequent cold air activities in the north and the frequent occurrence of strong winds can easily blow up the soil or sand on the surface, thus forming a dusty weather.

  "Since this year, most of the northern regions have experienced 6 large-scale sand and dust weather processes. This should be the seventh time." Li Liang, a meteorological analyst at China Weather Network, introduced.

  From January to March throughout the year, there will be an average of 5.3 sand and dust weather processes in my country. This year’s sand and dust weather processes are slightly more frequent, and the sand and dust weather processes from March 15 to March 18 have been encountered by China in the past 10 years. The most intense sand-dust weather process, and the range of sand-dust storms is also the widest in the past 10 years.

  From the perspective of the climate background, April is still a period of active sand and dust weather. This year, the overall sand source surface condition is poor, and sand and dust weather may still occur if it encounters favorable weather conditions.

  But this year's sand and dust weather also shows that under the influence of global warming, extreme weather continues to increase.

The atmosphere knows no borders, and dealing with sand and dust weather is not just a problem that a city or a country needs to face.