Long range transport of nitrate in the low atmosphere over Northeast Asia

In this study, the source-relationships were established for surface nitrate concentrations in Northeast Asia, using the Particulate Matter Source Apportionment Technology (PSAT) in the CAMx (a regional chemical transport model). Both of the local emissions and Chinese emissions were important among the sources of the particle nitrate in Japan and South Korea, accounting for 27.9–62.9% and 22.9–50.5% respectively. The local contributions of nitrate were 4–20% higher than the figures of sulfate, and this was caused by the different chemical processes and emissions involved. The seasonal variation of the nitrate concentration in East Asia led to different amounts of nitrate being attributed to long-range transport, and was higher in winter (>53%) than in summer (