A Multi-faceted Analysis of SO۲ Pollution in Tehran: Comparing Data Sources and Investigating Population Influence

Accurate monitoring of atmospheric sulfur dioxide (SO۲) is crucial for assessing air quality and understanding environmental impacts. This study investigates SO۲ pollution in Tehran Province, Iran, by comparing monthly concentration trends derived from two distinct data sources: Sentinel-۵ Precursor satellite observations and Giovanni NASA MERRA-۲ Reanalysis. The primary objectives were to assess the consistency and potential discrepancies between these datasets and to explore the relationship between SO۲ levels and population dynamics across sixteen cities within the province. Visual comparison of time series plots revealed a general agreement in the temporal patterns of SO۲ concentrations between Sentinel-۵ and MERRA-۲, indicating both sources capture the overarching seasonal and inter-annual variability. However, noticeable differences in the absolute magnitudes of SO۲ concentrations were also observed. Analysis of the correlation between monthly SO۲ concentrations and city populations did not demonstrate a strong linear relationship, suggesting that at this scale, factors beyond population size, such as localized emission sources and meteorological conditions, may play a more dominant role in influencing SO۲ variability within the region. The findings highlight the value of utilizing both satellite and reanalysis data for monitoring SO۲ trends, while also emphasizing the importance of acknowledging their inherent differences when making quantitative comparisons. The study suggests that while population contributes to overall emissions, the spatial distribution of sources and regional atmospheric processes are key determinants of local SO۲ concentrations in Tehran Province, necessitating further investigation into these complex interactions.

کلیدواژه ها:

Sulfur dioxide ، Spatiotemporal analysis ، Giovanni NASA ، Google earth engine