Application of concentration-weighted trajectory approach to identify sources with high anthropogenic mercury emissions in the East Asia

The study evaluates the applicability of the CWT method for identifying mercury sources in a region with high anthropogenic emissions. Analysis is conducted to compare results on grids of 1 × 1°, 0.5 × 0.5°, and 0.1 × 0.1°. New data on atmospheric atomic mercury concentrations over the Sea of Japan and the East China Sea are compared, with higher resolution enabling clearer source localization. Results show increased mercury concentrations in winter, likely due to the heating season, yet they remain lower than previous values. Comparing grid resolutions indicates higher resolution can better pinpoint sources and disregard some emissions. The analysis also confirms transboundary transfer of atomic mercury from northeast China to the southeast Korean Peninsula.