As the temperature rose and the spirit of spring began to fade, unwelcome’uninvited guests’ fine dust began to rise. The fine dust that hit the metropolitan area on the 11th is expected to remain’bad’ until the 15th due to atmospheric congestion.
Bucheon 195㎍/㎥, Gangdong-gu 141㎍/㎥
Emergency reduction measures issued in the metropolitan area today
Fine dust continues until a strong wind blows on the 16th
According to the Meteorological Administration, the average daily concentration of ultrafine dust in Seoul until 4 pm on the 11th was 99㎍/㎥. Incheon and Gyeonggi Province were 91㎍/㎥ and 96㎍/㎥, respectively, which were’very bad’. If it is more than 36㎍/㎥, it corresponds to’bad’, and if it is more than 76㎍/㎥, it corresponds to’very bad’. It means that the level of ultrafine dust in the metropolitan area on this day was 3-6 times worse than the day when it was in the’normal’ stage (16~35㎍/㎥). The concentration of ultrafine dust in Bucheon, Gyeonggi-do soared to 195㎍/㎥ during the day, and Gangdong-gu, Seoul once recorded a concentration of 141㎍/㎥. In addition, ultrafine dust raged throughout the day in various parts of the Midwest, including Chungnam (84㎍/㎥), Sejong (66㎍/㎥), Jeonbuk (64㎍/㎥), and Gwangju Metropolitan City (53㎍/㎥).
As a result, the first emergency measures to reduce fine dust in the metropolitan area were put in place on that day, limiting the operation of vehicles with class 5 emissions, and the operating hours of power plants and workplaces that discharge large amounts of pollutants. Emergency reduction measures are taken when the daily average ultrafine dust concentration is expected to be 50㎍/㎥ or more for two consecutive days. The government announced on the 12th that it would also issue emergency reduction measures. In addition, it is expected that the concentration of ultrafine dust will remain at a’bad’ level until the 15th as high pressure stays over the Korean peninsula for a long time.
Fine dust in spring is the main factor due to atmospheric congestion caused by atmospheric pressure patterns that occur during the changing seasons. Unlike winter in which cold high pressure in the north prevails overwhelmingly and summer in summer where warm high pressure in the south is dominant, there is little difference in air pressure in spring. Because of this, there is not much wind and the atmosphere is congested. Currently, high pressure remains over the Korean peninsula, and the weather with almost no wind continues. An official from the Integrated Forecasting Center for Fine Dust of the National Institute of Environmental Sciences said, “With little wind, the phenomenon of dust going out to the West Sea during the day and coming back to the land at night is repeated due to the temperature difference between night and day.”
The official predicted that “dust has accumulated from the night of the 7th in the Chungnam region and from the 8th in the metropolitan area and the inland region of the midwest,” and “the level of’bad’ will continue until the 15th for the time being.”
There is also a rain forecast, but it was expected to be of little help in resolving fine dust. From the night of the 11th to the night of the 12th due to the influence of the weak cyclone coming from China, it is expected to rain a little more than 20~60mm in the center of Jeju Island and the south coast, and 10~40mm in the southern part and the coastal area. It is predicted that less than 5mm of rain will also come in Seoul, Incheon, and northern Gyeonggi Province. An official from the Meteorological Agency said, “It is possible to expect a cleaning effect only when the rain continues to fall at least 5 mm per hour, but even if it rains in the central region, it will scatter at the level of raindrops.” He explained. An official from the Integrated Forecast Center said, “It is possible that the wind may blow slightly as it rains in the southern regions, but on the 13th there is a high possibility that the dust that went out to the west sea will return and accumulate, and high-density fine dust will reappear.” The forecasting center predicted that the concentration of ultrafine dust will be somewhat lowered by strong winds only on the 16th.
Reporter Kim Jeongyeon [email protected]
