S. Korea blanketed by extremely powerful yellow dust storm

MONDAY, MARCH 29, 2021

An extraordinarily strong yellow dust storm originating from the inland deserts in northern China blanketed all of South Korea on Monday, prompting authorities to issue a yellow dust warning for Seoul and almost all parts of the country.

The density of fine dust particles smaller than 10 micrometers in diameter, known as PM 10, surged to the "very bad" level in the greater Seoul area and almost all other regions, authorities said.

As of 7 a.m., the hourly average concentration of PM 10 reached 452 micrograms per cubic meter in Seoul, 681 micrograms in Daejeon, 653 micrograms in the central administrative city of Sejong, 522 micrograms in Gangwon Province, 421 micrograms in Ulsan and 401 micrograms in Gwangju, according to the state-run National Institute of Environmental Research's Air Quality Forecasting Center.

The weather authorities here categorize concentrations of PM 10 between zero and 30 micrograms as "good," between 31 and 80 as "normal," between 81 and 150 as "bad" and more than 151 as "very bad."

The PM 10 level reached a peak of 545 micrograms in Seoul on Monday morning, the center said, noting Busan and the southern resort island of Jeju registered bad levels of PM 10 reaching 98 and 109 micrograms, respectively.

The center explained that the latest onset of yellow dust here originated in the Inner Mongolian region in northern China and the vicinity of the Gobi Desert on Friday and moved south by riding the northwesterly winds.

It forecast the PM 10 reading will remain at the very bad level across the nation throughout Monday and at the bad level Tuesday due to residual yellow dust and atmospheric stagnation.

The Korea Meteorological Administration issued a yellow dust warning for Seoul as of 7:10 a.m., asking citizens with respiratory or cardiovascular problems, children and other vulnerable people to refrain from going outdoors.

A fine dust warning is issued when the PM 10 figure is forecast to stay above 800 micrograms per cubic meter for longer than two hours.

According to the air quality center, the density of ultrafine dust particles smaller than 2.5 micrometers in diameter, known as PM 2.5, also soared to the very bad level in almost all parts of the country, including the greater Seoul area.

As of 7 a.m., the hourly concentration of PM 2.5 rose to 96 micrograms in Seoul, 107 micrograms in Gyeonggi Province, 105 micrograms in North Chungcheong Province, 91 micrograms in Daejeon and 95 micrograms in North Jeolla Province.

South Korea's authorities have classified levels of PM 2.5 above 35 micrograms per cubic meter as "bad" and above 75 micrograms as "very bad," while the World Health Organization recommends keeping levels below 25 micrograms. (Yonhap)