Mountain meteorology and urban air quality: A five-year assessment of the Erzurum basin, Türkiye
Abstract
Mountain ecosystems are increasingly vulnerable to ecological stress, and cities located in mountainous areas face particular air quality problems arising from the combined effects of topography and atmospheric circulation. This study examines Erzurum, a high-altitude city in eastern Türkiye, in order to establish how mountain meteorology affects urban pollution. Hourly air pollution data for the five-year period 2021–2025 from five monitoring stations — Merkez, Taşan, Pasinler, Aziziye and Palandöken — were analysed, and the concentrations of PM10, PM 2.5 , NO 2 , SO 2 , CO and O 3 were compared across stations situated at different altitudes. Meteorological factors including wind speed, turbulence and boundary layer stability were also evaluated. The central urban stations consistently recorded the highest levels of PM 10 and NO 2 , mainly because of combustion emissions from traffic and residential heating combined with poor ventilation. Suburban and high-altitude stations showed lower concentrations of most primary pollutants but higher ozone levels. Pollutant accumulation was most intense under stagnant conditions with weak winds and night-time temperature inversions. Air quality in Erzurum therefore depends not only on emission sources but also on basin geometry and mountain–valley wind systems, and the integration of boundary layer processes into urban planning is essential for effective urban management.