A study of differences in PM2.5 concentrations at similar synoptic meteorological fields during the seasonal PM2.5 management from 2015 to 2019

Due to rapid urbanization and population growth, high aerosol pollution in the Korean Peninsula has become a major environmental concern. High concentrations of PM_2.5 in atmosphere is not only highly hazardous to humans, but also contributes significantly to visibility degradation and climate change. In study, K-means clustering analysis was performed to classify major synoptic patterns on the Korean Peninsula during the seasonal PM_2.5 management from 2015 to 2019. Also, we analyzed synoptic patterns according to the air quality on each cluster by dividing the PM_2.5 pollution standard into four levels to identify the differences in the occurrence of PM_2.5 concentrations in the similar meteorological environment. As a result, the synoptic patterns were classified into five clusters (C1~C5). The clusters (C1, C3, C4) with pressure gradient from east to west showed differences of PM_2.5 concentrations in Seoul as the pressure gradient between east and west changed. The clusters (C2, C5) with pressure gradients from south to north had different PM_2.5 concentrations in Seoul depending on the location and intensity of high pressure located in southeast of the Korean Peninsula and the intensity and location of high- and low-pressure systems located in the North Pacific and Kamchatka Peninsula, respectively. This study confirmed that air quality can vary depending on the location and strength of high- and low-pressure systems in the similar synoptic meteorological environment.