"Why is the sky so hazy?"
Seoul's skies have become trapped under a massive high-pressure dome, intensifying atmospheric stagnation and dryness. Pollutants are unable to escape, causing fine dust to accumulate, while continued rainless weather is also raising wildfire risks.
According to the Korea Meteorological Administration (KMA) and the Ministry of Climate, Energy and Environment on Sunday, a migratory high-pressure system lingering over the Korean Peninsula has stagnated at relatively low altitudes of 1 to 3 kilometers, forming a dome-like structure over the lower atmosphere. This pressure system, which split off from the Siberian High and moved in, blocks vertical air circulation and traps pollutants near the surface.
Air quality is expected to deteriorate further on Monday due to this effect. Fine dust concentrations are forecast at "bad" levels across most of the country, with the Seoul metropolitan area and North Chungcheong Province expected to spike to "very bad" levels during morning and nighttime hours. Domestically generated fine dust has accumulated due to atmospheric stagnation, and additional particulate matter from abroad is expected to flow in on northwesterly winds starting in the evening.
Air quality has already worsened. Since the beginning of this month, at least one of Seoul's 25 autonomous districts recorded ultrafine dust concentrations at "bad" or higher levels on 14 out of 24 days. Residents have been exposed to murky air for nearly half the month. On days when winds weakened, pollution levels surged sharply as domestically generated pollutants combined with particles from overseas sources.
Rainfall that could cleanse the atmosphere has also been insufficient. Cumulative precipitation in Seoul from the 1st to the 24th of this month measured 33.9 millimeters at the Seoul Observatory in Songwol-dong, down 10.5% from 37.9 millimeters during the same period last year. Compared with 2021 and 2022 when levels exceeded 100 millimeters, spring precipitation has been declining sharply each year.
The prolonged dry weather is also elevating wildfire risks. A fire broke out on a hillside in Bongyang-eup, Jecheon, North Chungcheong Province on Sunday, destroying 1.5 hectares of forest. Wildfires also erupted the previous day in Cheonan in South Chungcheong Province, Andong in North Gyeongsang Province, and Hoengseong in Gangwon Province, among other locations nationwide. The KMA has issued dry weather advisories for Seoul, southeastern Gyeonggi Province, eastern Gangwon Province, Daejeon, parts of North Chungcheong Province, Daegu, and inland areas of North Gyeongsang Province.
"A small spark can turn into a major blaze, so we urge the public to take extra caution in preventing wildfires and other fires," a KMA official said.
