{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2025,11,20]],"date-time":"2025-11-20T13:18:21Z","timestamp":1763644701112,"version":"build-2065373602"},"reference-count":25,"publisher":"MDPI AG","issue":"3","license":[{"start":{"date-parts":[[2025,8,25]],"date-time":"2025-08-25T00:00:00Z","timestamp":1756080000000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Pollutants"],"abstract":"<jats:p>This study investigated the extent to which the North Atlantic Oscillation (NAO) modulated daily surface-level concentrations of ozone (O3), nitrogen dioxide (NO2), and sulfur dioxide (SO2) on S\u00e3o Miguel Island, Azores, between 2017 and 2021. Using validated data from two air quality monitoring stations, S\u00e3o Gon\u00e7alo (SG) (urban background) and Ribeira Grande (RG) (semi-urban), we applied descriptive statistics, seasonal Pearson correlations, and robust linear regression models to assess pollutant responses to NAO variability. The results reveal a significant and positive association between NAO phases and O3 concentrations, particularly in spring and summer. NO2 levels exhibited a strong negative correlation with NAO during summer in urban settings, indicating enhanced atmospheric dispersion. In contrast, SO2 concentrations showed weak and inconsistent relationships with the NAO index, likely reflecting the influence of local and episodic sources. These findings demonstrate that large-scale synoptic drivers such as the NAO can significantly modulate pollutant dynamics in island environments and should be integrated into air quality forecasting and environmental health planning strategies in small island territories.<\/jats:p>","DOI":"10.3390\/pollutants5030027","type":"journal-article","created":{"date-parts":[[2025,8,26]],"date-time":"2025-08-26T06:25:57Z","timestamp":1756189557000},"page":"27","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":1,"title":["Synoptic-Scale Modulation of Surface O3, NO2, and SO2 by the North Atlantic Oscillation in S\u00e3o Miguel Island, Azores (2017\u20132021)"],"prefix":"10.3390","volume":"5","author":[{"ORCID":"https:\/\/orcid.org\/0000-0001-5935-870X","authenticated-orcid":false,"given":"Helena Cristina","family":"Vasconcelos","sequence":"first","affiliation":[{"name":"Faculty of Science and Technology, University of the Azores, 9500-321 Ponta Delgada, Portugal"},{"name":"Laboratory of Instrumentation, Biomedical Engineering and Radiation Physics (LIBPhys, UNL), Department of Physics, NOVA School of Science and Technology, 2829-516 Caparica, Portugal"}]},{"given":"Ana Catarina","family":"Ferreira","sequence":"additional","affiliation":[{"name":"Faculty of Science and Technology, University of the Azores, 9500-321 Ponta Delgada, Portugal"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-9356-3045","authenticated-orcid":false,"given":"Maria Gabriela","family":"Meirelles","sequence":"additional","affiliation":[{"name":"Faculty of Science and Technology, University of the Azores, 9500-321 Ponta Delgada, Portugal"},{"name":"Research Institute of Marine Sciences, University of the Azores (OKEANOS), 9901-862 Horta, Portugal"}]}],"member":"1968","published-online":{"date-parts":[[2025,8,25]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"5719","DOI":"10.1002\/2013JD021435","article-title":"Long-term changes in lower tropospheric baseline ozone concentrations: Comparing chemistry-climate models and observations at northern mid-latitudes","volume":"119","author":"Parrish","year":"2014","journal-title":"J. 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