Time filter

Source Type

Taean gun, South Korea

Park S.-Y.,Tokyo University of Agriculture | Park J.G.,Tokyo University of Information Sciences | Kim C.-S.,Kyungpook National University | Shin I.C.,Korea Global Atmosphere Watch Center
Asian Journal of Atmospheric Environment | Year: 2013

Methane concentrations have been monitored at the Anmyeon-do Observatory, Korea, since 1999. In recent years, the methane concentration has increased, but the sources of this increase have yet to be identified. This study was designed to identify the major source contributing to the increase by using World Data Centre for Greenhouse Gases (WDCGG) data and the Greenhouse Gases Emission Presumption (GEP) method. The data were collected at Anmyeon-do between 2003 and 2009 (except 2008), and the analyses showed that the increase in methane concentration originated mainly in rice paddies around the observation point. The annual average methane concentration at Anmyeon-do was 1894 ppb, of which 100-103 ppb (5.3-5.4%) was shown to originate mainly from rice paddies. The seasonal fluctuation in methane concentration from May to October estimated by the GEP method was compared with experimental data of previous research conducted on rice paddies. The close match obtained through this comparison shows that the GEP method is effective. The difference in methane concentration was also analyzed in terms of land use and land cover. It was shown that although rice paddies account for only 14.7% of the area surveyed, they accounted for between 69 and 90% of the total increase in methane concentration. These results confirm that rice paddies are the main source of the increase in methane concentration observed at Anmyeon-do.

Kim Y.,Korea Institute of Science and Technology | Kim S.-W.,Seoul National University | Yoon S.-C.,Seoul National University | Park J.-S.,National Institute of Environmental Research | And 6 more authors.
Atmospheric Research | Year: 2016

Measurements of the number concentration and size distribution of atmospheric nanoparticles were conducted at four sites on the west coast of the Korean Peninsula by using identical scanning mobility particle sizers (SMPSs) in October 2012. The new particle formation and subsequent growth (NPF) of atmospheric nanoparticles, which were identified by the cyclostationary empirical orthogonal function (CSEOF) analysis technique, was observed on 11 out of 21. days at the Baengnyeong-do Comprehensive Monitoring Observatory (BCMO); and on 10 out of 21. days at the Korea Global Atmosphere Watch Center (KGAWC) from October 9 to 29, 2012. We also observed NPF events for 9 out of 21. days at both the Gosan Climate Observatory (GCO) and the Jeju Comprehensive Monitoring Observatory (JCMO). During the study period, NPF was simultaneously observed for five days at all four sites, which indicates that the NPF event had a spatial extent of at least 540. km. A cold, dry and cloud-free continental air mass originated from northern China, formed favorable environmental conditions (e.g., increasing solar insolation at the surface) on simultaneous NPF at the four sites. These synoptic weather patterns were closely associated with an extraordinary typhoon passing over the south of Japan. The mean values of particle formation rates at BCMO (1.26cm-3s-1) and KGAWC (1.49cm-3s-1) were relatively higher than those at GCO (0.39cm-3s-1) and JCMO (0.74cm-3s-1), however, the growth rate showed a similar level among four sites. An increase in the spatial homogeneity and inter-site correlation of atmospheric particles among the four sites was apparent for small particles (diameter<30nm) on simultaneous NPF event days. © 2015 Elsevier B.V.

Park S.-H.,Pukyong National University | Panicker A.S.,Pukyong National University | Lee D.-I.,Pukyong National University | Jung W.-S.,Pukyong National University | And 6 more authors.
Journal of Atmospheric Chemistry | Year: 2010

This paper reports aerosol chemical properties for the first time over a Korean Global Atmosphere Watch (GAW) supersite, Anmyeon (36°32′N; 126° 19′E), during 2003-2004 period. Total suspended Particulates (TSP) showed significant seasonal variation with consistent higher mass concentrations during spring season (average of up to 230∈±∈190 μg/m 3). PM 10 also followed similar trend with higher concentrations during spring (average of up to 170∈±∈130 μg/m 3) and showed reduced concentrations during summer. PM 2.5 showed a significant increase during summer (average of up to 60∈±∈25 μg/m 3), which could be due to the influx of fine mode sea salt aerosols associated with the Changma front (summer monsoon). Chemical composition analysis showed enhanced presence of acidic fractions, majorly contributed by sulphates (SO 4 2- ) and nitrates (NO 3 - ) in TSP, PM 10 and PM 2.5 during different seasons. Enhanced presence of Calcium (Ca 2+) was observed during sand storm days during spring. The high correlation obtained on matrix analysis between crustal ions and acidic ions suggests that the ionic compositions over the site are mainly contributed by terrestrial sources of similar origin. The neutralization factors has been estimated to find the extend of neutralization of acidicity by main basic components, and found to have higher value for Ammonium (up to 1.1) in different seasons, indicating significant neutralization of acidic components over the region by NH 4 + . Back trajectory analysis has been performed during different seasons to constrain the possible sources of aerosol origin and the results are discussed in detail. © 2011 Springer Science+Business Media B.V.

Panicker A.S.,Indian Institute of Tropical Meteorology | Park S.-H.,Pukyong National University | Lee D.-I.,Pukyong National University | Kim D.-C.,University of Maryland Baltimore County | And 7 more authors.
Atmospheric Environment | Year: 2013

This paper provides an account of observed variations in Black carbon (BC) mass concentrations and BC induced radiative forcing for the first time over a background Global Atmosphere Watch (GAW) site, Anmyeon in South Korea. BC concentrations were continuously measured over the site during January 2003-December 2004 periods using an Aethalometer. BC showed higher concentrations during 2003 in majority of the months (except in January, August and October). BC found to be showing higher concentrations in September 2003, with values reaching up to 3μgm-3 over the site. It also showed higher peaks in May and December in 2003. BC values were found to be comparatively less during wet season (July-August; especially august), which could be associated with the rainout and washout associated with the Changma season (summer monsoon). Optical Properties of Aerosols and Clouds (OPAC) model in combination with a radiative transfer model (SBDART) were used to estimate aerosol radiative forcing separately for composite aerosols (total aerosols) and solely for BC aerosols using chemical composition data sets of Total Suspended Particulates (TSP) and BC. The atmospheric forcing for composite aerosols found to be+14.9 to+25.9Wm-2 during spring,+13.4 to+20.4Wm-2 in summer,+12.9 to+19.1Wm-2 in autumn and+16 to+18.2Wm-2 during winter,respectively. The respective BC atmospheric forcings were+8.1 to+11.8Wm-2,+8.4 to+11.1Wm-2,+8.7 to+11.4Wm-2 and+8.8 to+11.7Wm-2 during spring, summer, autumn and winter. The study suggests that BC induced atmospheric forcing can contribute up to 88% of total aerosol induced atmospheric warming. © 2013 Elsevier Ltd.

Kim W.-H.,Jeju National University | Ko H.-J.,Jeju National University | Hu C.-G.,Jeju National University | Lee H.,Korea Global Atmosphere Watch Center | And 4 more authors.
Bulletin of the Korean Chemical Society | Year: 2014

Real-time monitoring of hourly atmospheric radon (Rn-222) concentration was performed throughout 2011 at Gosan station, Jeju Island, one of the least polluted regions in Korea, in order to characterize the background levels, and temporal variations on diurnal to seasonal time-scales. The annual mean radon concentration for 2011 was 2527 ± 1356 mBq m-3, and the seasonal cycle was characterized by a broad winter maximum, and narrow summer minimum. Mean monthly radon concentrations, in descending order of magnitude, were Oct > Sep > Feb > Nov > Jan > Dec > Mar > Aug > Apr > Jun > May > Jul. The maximum monthly mean value (3595 mBq m-3, October), exceeded the minimum value (1243 mBq m-3, July), by almost a factor of three. Diurnal composite hourly concentrations increased throughout the night to reach their maximum (2956 mBq m-3) at around 7 a.m., after which they decreased to their minimum value (2259 mBq m-3) at around 3 p.m. Back trajectory analyses indicated that the highest radon events typically exhibited long-term continental fetch over Asia before arriving at Jeju. In contrast, low radon events were generally correlated with air mass fetch over the North Pacific Ocean. Radon concentrations typical of predominantly continental, and predominantly oceanic fetch, differed by a factor of 3.8.

Discover hidden collaborations