An exploration of meteorological effects on PM2.5 air quality in several provinces and cities in Vietnam

Abstract

Linking meteorology and air pollutants is a key challenge. The study investigated meteorological effects on PM_2.5 concentration using the advanced convergent cross mapping method, utilizing hourly PM_2.5 concentration and six meteorological factors across eight provinces and cities in Vietnam. Results demonstrated that temperature (ρ = 0.30) and radiation (ρ = 0.30) produced the highest effects, followed by humidity (ρ = 0.28) and wind speed (ρ = 0.24), while pressure (ρ = 0.22) and wind direction (ρ = 0.17) produced the weakest effects on PM_2.5 concentration. Comparing the ρ values showed that temperature, wind speed, and wind direction had greater impacts on PM_2.5 concentration during the dry season whereas radiation had a more influence during the wet season; Southern stations experienced larger meteorological effects. Temperature, humidity, pressure, and wind direction had both positive and negative influences on PM_2.5 concentration, while radiation and wind speed mostly had negative influences. During PM_2.5 pollution episodes, there was more contribution of meteorological effects on PM_2.5 concentration indicated by ρ values. At contaminated levels, humidity (ρ = 0.45) was the most dominant factor affecting PM_2.5 concentration, followed by temperature (ρ = 0.41) and radiation (ρ = 0.40). Pollution episodes were pointed out to be more prevalent under higher humidity, higher pressure, lower temperature, lower radiation, and lower wind speed. The ρ calculation also revealed that lower temperature, lower radiation, and higher humidity greatly accelerated each other under pollution episodes, further enhancing PM_2.5 concentration. The findings contributed to the literature on meteorology and air pollution interaction.

Keywords: Air pollution; Causality analysis; Convergent cross mapping; Fine particulate matter; Meteorological effect; Vietnam.