Decadal analysis of ammonia emission levels in the lowlands of eastern Germany using remote sensing data

Ammonia (NH₃) emissions play a significant role in air quality degradation, biodiversity loss, and human health risks by forming secondary pollutants such as fine particulate matter (PM_2.5). This study presents a decadal (2013–2022) spatiotemporal analysis of NH₃ emissions in the lowlands of eastern Germany, using data from the Infrared Atmospheric Sounding Interferometer (IASI-B) onboard the MetOp-B satellite. The region, characterized by predominantly agricultural land use (54.71%), offers a valuable case for understanding NH₃ emission dynamics across diverse landscapes. Integrating satellite remote sensing, machine learning, and atmospheric modeling, this analysis reveals pronounced seasonal and spatial variations, with agricultural activities identified as the primary source of emissions. K-means clustering highlights the influence of cropland, grassland, and urban areas on NH₃ emission patterns, identifying significant agricultural hotspots. Additionally, advanced geospatial analysis establishes significant correlations between NH₃ concentrations and meteorological variables. NH₃ emissions were positively associated with surface solar radiation, temperature, atmospheric boundary layer height, and convective available potential energy, while precipitation, moisture flux, and wind speed exhibited negative correlations. Backward trajectory dispersion modeling employing the HYSPLIT model provided insights into NH₃ transport pathways. The results confirmed the influence of both, local sources and non-local contributions. These findings show the major role of meteorological conditions in NH₃ dispersion and underscore the importance of sustainable agricultural practices in mitigating emissions.