Observations of atmospheric 14CO2 at Anmyeondo GAW station, South Korea: implications for fossil fuel CO2 and emission ratios
Authors: Lee Haeyoung , Dlugokencky Edward , Turnbull Jocelyn , Lehman Scott , Miller John , Pétron Gabrielle , Joo Sangwon , Kim Yeon-Hee 
Published: March 2021

&lt;p&gt;To understand the Korean Peninsula's carbon dioxide (CO&lt;span&gt;&lt;sub&gt;2&lt;/sub&gt;&lt;/span&gt;) emissions and sinks as well as those of the surrounding region, we used 70 flask-air samples collected during May&amp;#160;2014 to August&amp;#160;2016 at Anmyeondo (AMY; 36.53&lt;span&gt;&lt;sup&gt;&amp;#8728;&lt;/sup&gt;&lt;/span&gt;&amp;#8201;N, 126.32&lt;span&gt;&lt;sup&gt;&amp;#8728;&lt;/sup&gt;&lt;/span&gt;&amp;#8201;E; 46&amp;#8201;m&amp;#8201;a.s.l.) World Meteorological Organization (WMO) Global Atmosphere Watch (GAW) station, located on the west coast of South Korea, for analysis of observed&amp;#160;&lt;span&gt;&lt;sup&gt;14&lt;/sup&gt;&lt;/span&gt;C in atmospheric CO&lt;span&gt;&lt;sub&gt;2&lt;/sub&gt;&lt;/span&gt;&amp;#160;as a tracer of fossil fuel CO&lt;span&gt;&lt;sub&gt;2&lt;/sub&gt;&lt;/span&gt;&amp;#160;contribution (&lt;span&gt;&lt;em&gt;C&lt;/em&gt;&lt;sub&gt;ff&lt;/sub&gt;&lt;/span&gt;). Observed&amp;#160;&lt;span&gt;&lt;sup&gt;14&lt;/sup&gt;&lt;/span&gt;C&amp;#8201;&lt;span&gt;&amp;#8725;&lt;/span&gt;&amp;#8201;C ratios in CO&lt;span&gt;&lt;sub&gt;2&lt;/sub&gt;&lt;/span&gt;&amp;#160;(reported as&amp;#160;&lt;span&gt;&amp;#916;&lt;/span&gt;&amp;#160;values) at AMY varied from&amp;#160;&lt;span&gt;&amp;#8722;59.5&lt;/span&gt;&amp;#8201;&amp;#8240; to 23.1&amp;#8201;&amp;#8240;, with a measurement uncertainty of&amp;#160;&lt;span&gt;&amp;#177;1.8&lt;/span&gt;&amp;#8201;&amp;#8240;. The derived mean value&amp;#160;&lt;span&gt;&lt;em&gt;C&lt;/em&gt;&lt;sub&gt;ff&lt;/sub&gt;&lt;/span&gt;&amp;#160;of (&lt;span&gt;9.7&amp;#177;7.8&lt;/span&gt;)&amp;#8201;&lt;span&gt;&amp;#181;&lt;/span&gt;mol&amp;#8201;mol&lt;span&gt;&lt;sup&gt;&amp;#8722;1&lt;/sup&gt;&lt;/span&gt;&amp;#160;(&lt;span&gt;1&lt;em&gt;&amp;#963;&lt;/em&gt;&lt;/span&gt;) is greater than that found in earlier observations from Tae-Ahn Peninsula (TAP; 36.73&lt;span&gt;&lt;sup&gt;&amp;#8728;&lt;/sup&gt;&lt;/span&gt;&amp;#8201;N, 126.13&lt;span&gt;&lt;sup&gt;&amp;#8728;&lt;/sup&gt;&lt;/span&gt;&amp;#8201;E; 20&amp;#8201;m&amp;#8201;a.s.l., 28&amp;#8201;km away from AMY) of (&lt;span&gt;4.4&amp;#177;5.7&lt;/span&gt;)&amp;#8201;&lt;span&gt;&amp;#181;&lt;/span&gt;mol&amp;#8201;mol&lt;span&gt;&lt;sup&gt;&amp;#8722;1&lt;/sup&gt;&lt;/span&gt;&amp;#160;from 2004 to 2010. The enhancement above background mole fractions of sulfur hexafluoride (&lt;span&gt;&amp;#916;&lt;em&gt;x&lt;/em&gt;(SF&lt;sub&gt;6&lt;/sub&gt;)&lt;/span&gt;) and carbon monoxide (&lt;span&gt;&amp;#916;&lt;em&gt;x&lt;/em&gt;(CO)&lt;/span&gt;) correlate strongly with&amp;#160;&lt;span&gt;&lt;em&gt;C&lt;/em&gt;&lt;sub&gt;ff&lt;/sub&gt;&lt;/span&gt;&amp;#160;(&lt;span&gt;&lt;em&gt;r&lt;/em&gt;&gt;0.7&lt;/span&gt;) and appear to be good proxies for fossil fuel CO&lt;span&gt;&lt;sub&gt;2&lt;/sub&gt;&lt;/span&gt;&amp;#160;at regional and continental scales. Samples originating from the Asian continent had greater&amp;#160;&lt;span&gt;&amp;#916;&lt;em&gt;x&lt;/em&gt;(CO)&lt;/span&gt;&amp;#8201;:&amp;#8201;&lt;span&gt;&lt;em&gt;C&lt;/em&gt;&lt;sub&gt;ff&lt;/sub&gt;(&lt;em&gt;R&lt;/em&gt;&lt;sub&gt;CO&lt;/sub&gt;)&lt;/span&gt;&amp;#160;values, (&lt;span&gt;29&amp;#177;8&lt;/span&gt;) to (&lt;span&gt;36&amp;#177;2&lt;/span&gt;)&amp;#8201;nmol&amp;#8201;&lt;span&gt;&amp;#181;&lt;/span&gt;mol&lt;span&gt;&lt;sup&gt;&amp;#8722;1&lt;/sup&gt;&lt;/span&gt;, than in Korean Peninsula local air ((&lt;span&gt;8&amp;#177;2&lt;/span&gt;)&amp;#8201;nmol&amp;#8201;&lt;span&gt;&amp;#181;&lt;/span&gt;mol&lt;span&gt;&lt;sup&gt;&amp;#8722;1&lt;/sup&gt;&lt;/span&gt;). Air masses originating in China showed (&lt;span&gt;1.6&amp;#177;0.4&lt;/span&gt;) to (&lt;span&gt;2.0&amp;#177;0.1&lt;/span&gt;) times greater&amp;#160;&lt;span&gt;&lt;em&gt;R&lt;/em&gt;&lt;sub&gt;CO&lt;/sub&gt;&lt;/span&gt;&amp;#160;than a bottom-up inventory, suggesting that China's CO emissions are underestimated in the inventory, while observed&amp;#160;&lt;span&gt;&lt;em&gt;R&lt;/em&gt;&lt;sub&gt;SF6&lt;/sub&gt;&lt;/span&gt;&amp;#160;values are 2&amp;#8211;3&amp;#160;times greater than inventories for both China and South Korea. However,&amp;#160;&lt;span&gt;&lt;em&gt;R&lt;/em&gt;&lt;sub&gt;CO&lt;/sub&gt;&lt;/span&gt; values derived from both inventories and observations have decreased relative to previous studies, indicating that combustion efficiency is increasing in both China and South Korea. Since we confirmed the possibility to verify the bottom-up inventories using our measurement data, it will be presented the Korea IG3IS future plan in this presentation.&lt;/p&gt;