Chia-Hua Hsu, Fang-Yi Cheng 

Department of Atmospheric Sciences, National Central University, Taoyuan 32001, Taiwan

Received: September 17, 2018
Revised: December 16, 2018
Accepted: February 3, 2019
Download Citation: ||  

Cite this article:
Hsu, C.H. and Cheng, F.Y. (2019). Synoptic Weather Patterns and Associated Air Pollution in Taiwan. Aerosol Air Qual. Res. 19: 1139-1151.


  • Apply the cluster analysis to classify the synoptic weather patterns.
  • Study the characteristic of PM2.5, PM10, and O3 in each weather pattern.
  • The weak synoptic weather pattern exhibits the lowest wind speed and highest PM2.5.
  • The worst air pollution problem occurs in the southwestern Taiwan.
  • Due to mountain blocking, the stagnant wind condition forms that traps the air pollutants.


In this study, cluster analysis is applied to the daily averaged wind fields and sea-level pressure observed at surface weather stations in Taiwan from January 2013 to March 2018 to classify the synoptic weather patterns and study the characteristics of corresponding air pollutants, including fine particulate matter (PM2.5), coarse particulate matter (PM10), and ozone (O3). The classification identified six weather types: Clusters 1, 2, and 3 (C1–C3), which are typical winter weather types and associated with high air pollutant concentrations—C3, in particular, influenced by weak synoptic weather, is associated with the lowest wind speeds and the highest PM2.5 and PM10 concentrations and represents the most prevalent weather type that is prone to the occurrence of PM2.5 events; C4, which occurs mostly during seasonal transition months and is associated with the highest O3 concentrations; and C5 and C6, which are summer weather types with low air pollutant concentrations.

Further analysis of the local wind flow using the 0.3° ERA5 reanalysis dataset and surface-observed wind data indicates that in western Taiwan, the land-sea breeze is embedded within the synoptic weather type of C3, which is favorable to air pollutant accumulation. However, when the prevailing northeasterly wind is obstructed by the Central Mountain Range, southwestern Taiwan, being situated on the leeside of the mountains, often exhibits the worst air pollution due to stagnant wind conditions.

Keywords: Synoptic weather classification; Cluster analysis; PM2.5; Ozone; Stagnant wind


Don't forget to share this article 


Subscribe to our Newsletter 

Aerosol and Air Quality Research has published over 2,000 peer-reviewed articles. Enter your email address to receive latest updates and research articles to your inbox every second week.

Latest coronavirus research from Aerosol and Air Quality Research

2018 Impact Factor: 2.735

5-Year Impact Factor: 2.827

SCImago Journal & Country Rank