The Gosan GAW Regional Station (Global Atmosphere Watch, program of the World Meteorological Organization) is located on the south-western tip of Jeju Island (Republic of Korea), facing the East China Sea. The station rests at the top of a 72 m cliff, about 100 km south of the Korean peninsula, 500 km northeast of Shanghai, China, and 250 km west of Kyushu, Japan.
Jeju Island is regarded as one of the cleanest areas in South Korea, with low emissions of air pollutants. As it is known, Gosan Station is one of the most important sites for monitoring the outflows from the Asian continent. Weekly flask sampling began in 1990 for monitoring the atmospheric CO2 concentrations and contributing to the GLOBALVIEW-CO2 data product. Continuous, in situ observations for CO2 using a LOFLO system have been tracked since 2007.
The Medusa GC-MS system was established at Gosan in 2007 and has been operated as part of the AGAGE network to take high-precision, high-frequency measurements for a wide range of HCFCs, HFCs, PFCs, Halons and other halocarbons. In situ data for atmospheric CH4 and CO are also obtained at Gosan by FID-GC and NDIR systems, respectively. For better understanding for natural variability of atmospheric CO2 and CH4, in situ hourly measurements for δ13C of CO2 and CH4 were started in 2013 using cavity ring-down spectroscopy.