The characteristics of tropospheric CO₂ retrieved by AIRS, GOSAT and IASI in East Asia

AIRS, GOSAT and IASI satellite data were validated to analyze the temporal and spatial distribution of the mid-tropospheric carbon dioxide (CO₂) concentration in East Asia. The mid-Atmospheric retrieval data of GOSAT was reflected in the seasonal characteristics with the correlation coefficient of 0.94 in comparison with the ground-based CO₂ data at Anmyeondo in Korea during the period of a year in 2011, On the other hand, the correlation coefficient between the AIRS data and the Anmyeondo data was 0.4 but the RMSE was the minimum in 4.46 among them. In addition, the AIRS data were compared by the groundbased data measured at Mauna Loa in USA, Waliguan in China and Ryori in Japan and Anmyeondo in Korea for the periods of 9 years from 2003 to 2011. The ground-based CO₂ concentrationdata of Mauna Loa located at the highest elevation was in the high correlation coefficient of 0.95 in comparison with the AIRS data and those of Waliguan, Ryori and Anmyeondo were seen in 0.82, 0.78 and 0.69 respectively. The mid-tropospheric CO₂ concentration from 375 ppm to 390ppm during the period of 2003 through 2010 at Mauna Loa and Waliguan was in that of the global background on the 700 hPa surface. The ground-based CO₂ concentration from 375ppm to 395ppm during the period at Anmyeondo was in agreement with that of Ryori similar to the meteorological characteristics such as back trajectories and atmospheric stability. However, the mid-tropospheric CO₂ concentrations between Anmyeondo and Ryori were affected by meteorological conditions such as atmospheric vorticity and wind speed on 700 hPa. Furthermore, the higher mid-tropospheric CO₂ concentration zone, a dominant transport pathway, was in 30 o N to 60 o N range during the period from 2003 to 2011. The enhancement CO₂ concentration levels were in dry areas such as Gobbi, Mongolian and Manchuria deserts in East Asia which were related to the longrange transport, CO₂ emissions by human activities and sinking from photosynthesis along with the strong westerly wind zone.