Mungyeong, South Korea
Mungyeong, South Korea

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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.

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.

Song J.-M.,Jeju National University | Kim W.-H.,Jeju National University | Kang C.-H.,Jeju National University | Lee H.,Korea Global Atmosphere Watch Center | And 3 more authors.
Bulletin of the Korean Chemical Society | Year: 2015

Atmospheric radon-222 (radon) measurements were made from 2009 to 2013 at the Gosan station of Jeju Island, one of the cleanest regions in Korea, in order to characterize the temporal variability (on diurnal, seasonal, and annual scales) and analyze the influence of changing air mass transport pathways on observed radon concentrations. The mean hourly radon concentration over the whole period was 2441 ± 1037 mBq/m3. The seasonal cycle of radon at the Gosan station was characterized by a fall maximum and summer minimum, consistent with a reduction in nonfrozen terrestrial fetch from fall to summer. In order, the seasonal mean radon concentrations were 2962 mBq/m3 (fall) >2907 mBq/m3 (winter) >2219 mBq/m3 (spring) >1756 mBq/m3(summer). Based on a 5-year composite, the maximum mean monthly radon concentration in October (3100 mBq/m3) was more than twice the July minimum (1471 mBq/m3). Diurnal composite radon concentrations for the whole period increased throughout the night to a maximum of 2788 mBq/m3 at around 7 a.m., and then gradually decreased to a minimum of 2050 mBq/m3 at around 3 p.m. The winter diurnal cycle had a small amplitude due to the low variability in atmospheric mixing depth associated with recent air mass fetch over the Yellow Sea. The diurnal cycle in summer, however, exhibited a relatively large amplitude due to changes in atmospheric mixing depth associated with recent fetch over Jeju Island. Back trajectory analysis showed that high radon events were typically associated with long-term air mass fetch over continental Asia. Specifically, the average radon concentration of air masses originating from China was about 2.4 times higher than that of air masses originating from the North Pacific Ocean. © 2015 Korean Chemical Society & Wiley-VCH Verlag GmbH & Co. KGaA.

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.

Kim Y.,Seoul National University | Yoon S.-C.,Seoul National University | Kim S.-W.,Seoul National University | Kim K.-Y.,Seoul National University | And 2 more authors.
Atmospheric Environment | Year: 2013

This study is based on 3-year continuous measurements (January 2008-December 2010) of aerosol number size distributions recorded with a Scanning Mobility Particle Sizer (SMPS) at two regional background stations, Gosan Climate Observatory (GCO) and Korea Global Atmosphere Watch Center (KGAWC), in Korea. We identified new particle formation and growth (NPF) events by applying the Cyclostationary Empirical Orthogonal Function (CSEOF) technique to aerosol number size distributions. Based on the first mode loading vectors and the corresponding principle components in the CSEOF analysis, we classified strong, weak, and non NPF days. A strong NPF event was observed on 7.5% of days (60 days out of a total 800 days) at GCO and on 14.6% of days (140 days out of a total 958 days) at KGAWC. The maximum occurrence of strong NPF events was reported in spring at GCO, but in winter at KGAWC. Only 16 of these days were considered as simultaneous NPF events, and 7 days were identical NPF events. The airmass history analysis on simultaneous NPF days indicated the NPF events to be associated with a fast-moving cold and dry airmass from the Asian continent after the passage of a frontal system. The particle formation rate (FR) and growth rate (GR) were estimated to be 1.44 (1.20) cm-3 s-1 and 4.4 (4.7) nm h-1, respectively, at GCO and KGAWC (in parentheses). Almost identical values for the condensation sink were estimated in strong NPF (8.3 × 10-3 s-1) and non NPF (8.2 × 10-3 s-1) events at GCO, whereas the condensation sink for strong NPF days (8.5 × 10-5 s-1) was lower than that of non NPF days (1.1 × 10-2 s-1) at KGAWC. The FR, GR, condensation sink, and vapor source rate at both GCO and KGAWC were lower than those reported in polluted urban areas, but higher than those at clean sites. © 2012 Elsevier Ltd.

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.

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