High-Precision (¡_0.1 ppm), high-frequency (hourly averaged) measurement of atmospheric carbon dioxide (CO2) was made at Gosan Station on Jeju Island, Korea, using a Non-dispersive Infrared (NDIR) analyzer calibrated with National Oceanic and Atmospheric Administration/Earth Sys tem Re search Laboratory standards. This paper presents the one-year results from these measurements, including discussions on data quality control and data selection, data characteristics through comparing with other regional data and on the techniques for estimating potential source regions of pollution emissions in Northeast Asia with pollution events in the record.
Comparisons of the continuous monitoring data with in dependent flask measurements at Gosan show good correlation in overall trend. In addition, the continuous monitoring data show signals of extreme pollution and sink episodes which are difficult to monitor indiscrete flask measurements, showing the importance of continuous measurements.
The CO2 concentrations of "representative data" at Gosan, derived by the statistical pollution identification procedure, show strong season ality similar to those of other background observaories in the middle-to-high Northern Hemisphere. The amplitude of the seasonal variation at Gosan is approximately 16 ppm, similar to high-latitude Northern Hemi sphere marine sites such as Ryori and Point Barrow stations.
A hybrid receptor model was applied to the "regional pollution events", a statistically extracted subset of the data with a high probability of being influenced by regional pollution for under standing the distribution and strengths of the major CO2 pollution sources in the Northeast Asia region. Results indicate strong potential source areas around the Yangtze River region including Shanghai and the Huabei plain including Beijing of China, as well as the Korean peninsula including Seoul contributing to pollution events observed at Gosan.
The methodologies and results de scribe our continuing efforts in establishing a "top-down" estimation of green house gas emissions in the North east Asia region, important for scientific validation and monitoring of anthropogenic CO2 emissions from the active industrial development in this region.