Assessment of air quality in North Korea from satellite observations.

North Korea's air quality is poorly understood due to a lack of reliable data. Here, we analyzed urban- to national-scale air quality changes in North Korea using multi-year satellite observations. Pyongyang, Nampo, Pukchang, and Munchon were identified as pollution hotspots.

The implication of the air quality pattern in South Korea after the COVID-19 outbreak.

By using multiple satellite measurements, the changes of the aerosol optical depth (AOD) and nitrogen dioxide (NO) over South Korea were investigated from January to March 2020 to evaluate the COVID-19 effect on the regional air quality. The NO decrease in South Korea was found but not significant, which indicates the effects of spontaneous social distancing under the maintenance of ordinary life. The AODs in 2020 were normally high in January, but they became lower starting from February.

Regional characteristics of NO column densities from Pandora observations during the MAPS-Seoul campaign.

Vertical column density (VCD) of nitrogen dioxide (NO2) was measured using Pandora spectrometers at six sites on the Korean Peninsula during the Megacity Air Pollution Studies-Seoul (MAPS-Seoul) campaign from May to June 2015. To estimate the tropospheric NO VCD, the stratospheric NO VCD from the Ozone Monitoring Instrument (OMI) was subtracted from the total NO VCD from Pandora. European Centre for Medium-Range Weather Forecasts (ECMWF) reanalysis wind data was used to analyze variations in tropospheric NO VCD caused by wind patterns at each site.