{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2025,10,12]],"date-time":"2025-10-12T01:25:52Z","timestamp":1760232352029,"version":"build-2065373602"},"reference-count":60,"publisher":"MDPI AG","issue":"21","license":[{"start":{"date-parts":[[2022,10,24]],"date-time":"2022-10-24T00:00:00Z","timestamp":1666569600000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"National Research Foundation of Korea (NRF)","award":["NRF-2018R1A5A1024958","2020M3G1A1114617"],"award-info":[{"award-number":["NRF-2018R1A5A1024958","2020M3G1A1114617"]}]},{"name":"Ministry of Science and ICT","award":["NRF-2018R1A5A1024958","2020M3G1A1114617"],"award-info":[{"award-number":["NRF-2018R1A5A1024958","2020M3G1A1114617"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Remote Sensing"],"abstract":"<jats:p>Fine particulate matter (PM) significantly affects visibility, a sensitive indicator of air pollution. Despite a continuous decrease in the PM concentrations in South Korea, the public generally believes that PM air pollution has worsened over the past years. To explain this disparity, we analyzed the characteristics of recent visibility changes using observations of visibility and PM component data observed in Seoul, South Korea, from 2012 to 2018. A significant negative correlation (R = \u22120.96) existed between visibility and concentrations of PM, with an aerodynamic diameter \u2264 2.5 \u03bcm (PM2.5); a high PM2.5 concentration was the most important contributor to poor visibility. Annual mean PM2.5 concentrations in Seoul decreased by \u22125.1% yr\u22121 during 2012\u20132018, whereas annual mean visibility improved by 2.1% yr\u22121. We found that a lower improvement in visibility was associated with changes in the PM component. Among the PM components affecting poor visibility, contributions of ammonium nitrate (NH4NO3) significantly increased during 2012\u20132018 (from 48% in 2012 to 59% in 2018). Increases in NO3\u2212 aerosol concentrations were owing to SOx emission reduction and the resulting decreases in SO42\u2212 aerosol concentrations, which led to an increase in NH3 available for additional NH4NO3 production in the atmosphere. Despite decreased PM concentrations in Seoul, the change of PM components has compromised visibility improvement; thus, NO3\u2212 concentrations need to be reduced.<\/jats:p>","DOI":"10.3390\/rs14215310","type":"journal-article","created":{"date-parts":[[2022,10,24]],"date-time":"2022-10-24T10:09:23Z","timestamp":1666606163000},"page":"5310","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":9,"title":["Compromised Improvement of Poor Visibility Due to PM Chemical Composition Changes in South Korea"],"prefix":"10.3390","volume":"14","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-0603-2295","authenticated-orcid":false,"given":"Jaein I.","family":"Jeong","sequence":"first","affiliation":[{"name":"School of Earth and Environmental Sciences, Seoul National University, Seoul 08826, Korea"}]},{"given":"Jisu","family":"Seo","sequence":"additional","affiliation":[{"name":"School of Earth and Environmental Sciences, Seoul National University, Seoul 08826, Korea"}]},{"given":"Rokjin J.","family":"Park","sequence":"additional","affiliation":[{"name":"School of Earth and Environmental Sciences, Seoul National University, Seoul 08826, Korea"}]}],"member":"1968","published-online":{"date-parts":[[2022,10,24]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"102","DOI":"10.1513\/pats.200908-083RM","article-title":"Indoor air pollution and asthma in children","volume":"7","author":"Breysse","year":"2010","journal-title":"Proc. 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