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Kim H.-S.,Korea Center for Atmospheric Environment Research | Chung Y.-S.,Korea Center for Atmospheric Environment Research | Tans P.P.,National Oceanic and Atmospheric Administration
Air Quality, Atmosphere and Health | Year: 2014

Carbon dioxide (CO2) concentrations and the isotope composition (δ13C) were analyzed in Mt. Waliguan (WLG), China; Ulaan Uul (UUM), Mongolia; Tae-ahn Peninsula (TAP), Korea; Ryori (RYO), Japan; and Mauna Loa (MLO), Hawaii during 1991-2011. The average CO2 growth rate at MLO was 1.7 ppm year-1 during 1993-2004 and accelerated to 2.0 ppm year-1 during 2005-2011. The average difference from MLO during 1993-2004 was 0.27, 0.98, 4.18, and 2.83 ppm for WLG, UUM, TAP, and RYO, respectively. During 2005-2011, the average differences for WLG, UUM, TAP, and RYO increased to 0.33, 1.40, 5.81, and 2.99 ppm. Also, the annual range of CO2 at TAP has become large compared with MLO. CO2 concentrations at TAP, located on the downwind site of China, are increasing slightly faster than in the rest of the Northern Hemisphere, especially since about 2005. The long-term increase is caused by the burning of fossil fuels, although with some year-to-year variation caused by terrestrial ecosystems. CO2 concentration increases were due to the consumption of fossil fuels for heating in winter and agricultural activities in spring. The variations of δ13C reflect the large seasonal variation and increasing trend of CO2. The integrated value of δ13Cs of the sources in the East Asian region ranges from -28.0 to -27.1 ‰, with CO2, which was emitted by fossil fuels, being added. Airflow that arrived at TAP was divided into continental background (CBG) route, regionally polluted continental (RPC) route, and oceanic background (OBG) route. CO2 concentration was higher in CBG and RPC routes, and δ13C stayed at a low value. The isotopic fractionation factor of sources and sinks in the three sectors CBG, RPC, and OBG was -27.5 ± 0.3 ‰ (one sigma), -29.0 ± 0.6, and -23.0 ± 1.5 ‰, respectively. In the RPC route, traversing the industrial regions in eastern China where fossil fuels are consumed in large quantities, the lightest δ13C value was registered. Lower CO2 concentrations and heavier δ13C values were dominant in summer in OBG signatures. © 2014 Springer Science+Business Media Dordrecht. Source


Chung Y.S.,Korea Center for Atmospheric Environment Research | Kim H.-S.,Korea Center for Atmospheric Environment Research | Chun Y.,Korea Meteorological Administration
Asia-Pacific Journal of Atmospheric Sciences | Year: 2014

Dust air pollution has been routinely monitored in central Korea for the last two decades. In 2009, there were eight typical episodes of significant dust loadings in the air: four were caused by dust storms from deserts in Mongolia and Northern China, while the remaining were typical cases of anthropogenic air pollution masses arriving from the Yellow Sea and East China. These natural dust loadings occurred with cool northwesterly airflows in the forward side of an intense anticyclone coming from Mongolia and Siberia. The mean concentrations of the four natural dustfall cases for TSP, PM10 and PM2.5 were 632, 480 and 100 μg m-3, respectively. In contrast, the anthropogenic dust-pollution episodes occurred with the warm westerly and southwesterly airflows in the rear side of an anticyclone. This produced a favorable atmospheric and chemical condition for the build-up of anthropogenic dust air pollution in the Yellow Sea. The mean concentrations of the four anthropogenic dust loadings for TSP, PM10 and PM2.5 were 224, 187 and 137 μg m -3, respectively. The contents of fine dust loadings of PM2.5 were comparatively high in the cases of anthropogenic air pollution. High atmospheric concentrations of fine particles in the atmosphere cause poor visibility and constitute a health hazard. Satellite observations clearly showed the movement of dust-pollution masses from Mongolia and Northern China and from the Yellow Sea and East China that caused these dust pollution episodes in Korea. © 2014 The Korean Meteorological Society and Springer. Source


Kim H.S.,Korea Center for Atmospheric Environment Research | Chung Y.S.,Korea Center for Atmospheric Environment Research | Tans P.P.,National Oceanic and Atmospheric Administration
Asia-Pacific Journal of Atmospheric Sciences | Year: 2010

The carbon monoxide (CO) concentrations observed at Mt Waliguan in China (WLG), Ulaan Uul in Mongolia (UUM), Tae-ahn Peninsula in Korea (TAP) and Ryori in Japan (RYO) were analysed between 1991 and 2008. The average annual concentration of CO, a toxic air pollutant, was the highest at TAP (235±44 ppb), followed by RYO (169±35 ppb), UUM (154±27 ppb) and WTG (138±24 ppb). These data obtained in East Asia were also compared with CO data from Mauna Loa, Hawaii. CO tends to be highest in spring and lowest in summer in East Asia, with the exception of WLG. TAP had the highest CO concentrations in all seasons compared with WLG, UUM and RYO, and displays a wide short-term variability in concentration. This is caused by large-scale air pollution owing to its downwind location, close to continental East Asia. CO concentrations observed at TAP were analysed as follows: according to the origin of the isentropic backward trajectory and its transport passage; as continental background airflows (CBG); regionally polluted continental airflows (RPC); oceanic background airflows (OBG); and partly perturbed oceanic airflows (PPO). The high concentrations of CO at TAP are because of the airflow originating from the East Asian continent, rather than the North Pacific. RPCs, which pass through eastern China, appear to have high CO concentrations in spring, autumn and winter. It is noteworthy that the overall trend at TAP does not show an increase despite the fact that energy use in China approximately doubled from 1991 to 2008. OBGs, however, are affected by North Pacific air masses with low CO concentrations in summer. © The Korean Meteorological Society and Springer 2010. Source


Kim H.-S.,Korea Center for Atmospheric Environment Research | Chung Y.-S.,Korea Center for Atmospheric Environment Research | Kim J.-T.,Korea National University of Education
Asia-Pacific Journal of Atmospheric Sciences | Year: 2014

Long-term variations and trends of atmospheric aerosols in the East Asian region were analyzed by using aerosol optical depth (AOD or τ), and angström exponent (AE or α) obtained from the Moderate Resolution Imaging Spectroradiometer (MODIS) from 2001 to 2010. The increased emission of anthropogenic fine aerosols in east China resulted in the high AOD in this region during summer. The steady increasing emission of anthropogenic fine aerosols caused an increasing trend of AOD in east China, and the large-scale transport of sandstorms and smoke plume caused by forest fires affected intense inter-annual variations of AOD in the East Asian region. While in the central part of South Korea, located in the lee side of the East Asian continent, AE tended to rise to a level higher than in east China, the ground-based mass concentrations continued to decline. A noticeable decrease of PM10 mass concentration in spring and winter in central Korea is most likely attributable to decreases in sandstorms in the source region of East Asia. However, the ratio of PM2.5 mass concentration to PM10 increases overall with a high level in summer. Aerosol types were classified into dust, smoke plume, and sulphate by using satellite data over Cheongwon in central Korea. The columnar AOD, with different aerosol types, was compared with the ground-based mass concentrations at Cheongwon, and the relatively high level of the correlations presented between PM2.5 and AOD produced in sulphate. Growth and increases of fine hygroscopic aerosols generated as gas-to-particle conversion particularly in summer contribute to increases of columnar AOD in the East Asian region. © The Korean Meteorological Society and Springer 2014. Source


Kim H.-S.,Korea Center for Atmospheric Environment Research | Chung Y.-S.,Korea Center for Atmospheric Environment Research | Lee S.-G.,Korea Aerospace Research Institute
Environmental Monitoring and Assessment | Year: 2013

Satellite-retrieved data on aerosol optical depth (AOD) and Ångström exponent (AE) using a moderate resolution imaging spectrometer (MODIS) were used to analyze large-scale distributions of atmospheric aerosols in East Asia. AOD was relatively high in March (0.44 ± 0.25) and low in September (0.24 ± 0.21) in the East Asian region in 2009. Sandstorms originating from the deserts and dry areas in northern China and Mongolia were transported on a massive scale during the springtime, thus contributing to the high AOD in East Asia. However, whereas PM10 with diameters ≤10 μm was the highest in February at Anmyon, Cheongwon, and Ulleung, located leeward about halfway through the Korean Peninsula, AOD rose to its highest in May. The growth of hygroscopic aerosols attendant on increases in relative humidity prior to the Asian monsoon season contributed to a high AOD level in May. AE typically appears at high levels (1.30 ± 0.37) in August due to anthropogenic aerosols originating from the industrial areas in eastern China, while AOD stays low in summer due to the removal process caused by rainfall. The linear correlation coefficients of the MODIS AOD and ground-based mass concentrations of PM10 at Anmyon, Cheongwon, and Ulleung were measured at 0.4~0.6. Four cases (6 days) of mineral dustfall from sandstorms and six cases (12 days) of anthropogenically polluted particles were observed in the central area of the Korean Peninsula in 2009. PM10 mass concentrations increased at both Anmyon and Cheongwon in the cases of mineral dustfall and anthropogenically polluted particles. Cases of dustfall from sandstorms and anthropogenic polluted particles, with increasing PM10 mass concentrations, showed higher AOD values in the Yellow Sea region. © 2012 Springer Science+Business Media B.V. Source

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