Seasonality of airborne bacterial population in South Korea

Airborne bacteria are a critical yet highly dynamic component of atmospheric ecosystems, shaped by the interplay between local sources and long-range transport. Over a three-year monitoring period in Busan, South Korea, we quantified airborne bacterial populations using quantitative PCR and high-throughput sequencing. Bacterial concentrations fluctuated substantially (2.8–5.8 log10 copy·m-3), with pronounced peaks in spring and minima during summer. These fluctuations mirrored the temporal trends of both local PM10 and desert-derived PM10 transported from arid regions thousands of kilometers away. Time-series analyses further revealed robust, synchronized annual cycles for bacterial abundance, desert PM10, and local PM10 (P