http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
- 中文 을 입력하시려면 zhongwen을 입력하시고 space를누르시면됩니다.
- 北京 을 입력하시려면 beijing을 입력하시고 space를 누르시면 됩니다.
RISS 인기검색어
- 검색키워드
- 저자 : Jinsang Jung (검색결과 51 건)
- 무료
- 기관 내 무료
- 유료
-
-
-
Jung, Jinsang,Lee, JaeYong,Kim, ByungMoon,Oh, SangHyub Elsevier 2017 Atmospheric environment Vol.165 No.-
<P>This paper investigates the NO2 artifact associated with the chemiluminescence measurement technique that uses a molybdenum converter by applying the same technique but with a photolytic converter at a site downwind of the Asian continental outflow (Daejeon, Korea). The NO2 to NO conversion efficiencies of the molybdenum and photolytic converters were found to be 100% and 95%, respectively, at an ambient level of NO2 (<100 ppbv). Two NO2 monitors equipped with molybdenum and photolytic converters were deployed for ambient NO2 measurements in Daejeon, Korea between the fall of 2015 and the summer of 2016. It was found that the monitor equipped with the molybdenum converter overestimated NO2 levels by 20.4 +/- 14.7% when compared with the actual NO2 level in the Daejeon atmosphere over the entire measurement period. This NO2 artifact (Delta NO2),A defined as the difference between molybdenum NO2 and photolytic NO2 values, correlated well with the PM2.5 mass concentration during the fall and winter seasons. Based on these findings, this study develops a simple correction model for Delta NO2 using the PM2.5 mass concentration during the fall and winter seasons. The model-corrected NO2 concentration correlated well with the actual NO2 values with a slope of approximately 1.0 and R-2 value of 0.98 during the fall and winter seasons. (C) 2017 Elsevier Ltd. All rights reserved.</P>
-
Jung, Jinsang,Kim, Young J.,Aggarwal, Shankar Gopala,Kawamura, Kimitaka Elsevier 2011 Atmospheric environment Vol.45 No.16
<P><B>Abstract</B></P><P>The hygroscopic properties of the water-soluble matter extracts of atmospheric aerosols collected at an urban site (47.92° N, 106.90° E, ∼1300m above sea level) in Ulaanbaatar, Mongolia during the cold winter of 2007 were investigated using a hygroscopicity tandem differential mobility analyzer (H-TDMA). Dynamic shape correction factor (<I>χ</I>), the ratio of the actual drag force on a non-spherical aerosol particle to that on a sphere of equivalent volume, of the laboratory generated water-soluble matter (WSM) was found to be 1.09–1.38 (avg. 1.23±0.10), implying that particles generated from the WSM are highly non-spherical. The reduction in the mobility diameter can cause ∼11% underestimation in a hygroscopic growth factor at 85% RH. The hygroscopic growth factors at 85% RH (<I>g</I>(85%)), defined as the ratio of the particle diameter at 85% RH to that at RH<10% (initial dry diameter), of the WSM (initial dry particle diameter=100nm) were 1.32–1.50 (avg. 1.40±0.06). The <I>g</I>(RH) of the water-soluble organic matter (WSOM) was retrieved from the measured <I>g</I>(RH) of the WSM and using the ZSR (Zdanovskii–Stokes–Robinson) approach and the thermodynamic aerosol inorganic model (AIM). We found that the <I>g</I>(85%) of the WSOM were in the range of 1.11–1.35 (avg. 1.22±0.08), which are comparable to those of the biomass burning aerosols.</P> <P><B>Graphical abstract</B></P><P><ce:figure id='dfig1'></ce:figure></P><P><B>Highlights</B></P><P>► Mobility diameter shows substantial reduction at 20–40% RH. ► Laboratory generated particles are highly non-spherical shape. ► Hygroscopic growth factor of water-soluble organic aerosols is 1.22±0.08 at 85% RH. ► These growth factors are comparable to biomass burning aerosol and aged organics.</P>
-
Jung, Jinsang,Lee, Hanlim,Kim, Young J.,Liu, Xingang,Zhang, Yuanhang,Hu, Min,Sugimoto, Nobuo American Geophysical Union 2009 Journal of geophysical research Vol.114 No.d2
<P>In order to investigate the optical properties of atmospheric aerosol in the urban area of Beijing, in situ and remote measurements of particulate pollutants were conducted at an urban site (39.98 degrees N, 116.35 degrees E, similar to 20 m above ground level) in Beijing during the Campaign of Air Quality Research in Beijing (CAREBeijing) campaign from 16 August to 10 September 2006. During the intensive measurement period, average PM2.5 mass concentration and light extinction coefficient (b(ext)) were measured to be 102.1 +/- 55.0 mu g m(-3) and 880.7 +/- 685.9 Mm(-1), respectively. Average mass scattering efficiency of PM10 and PM2.5 particle were found to be 2.5 +/- 1.1 and 3.4 +/- 1.2 m(2) g(-1), respectively. Average single scattering albedo (SSA) of dry PM10 was characterized to be 0.82 +/- 0.09. It was found that SSA decreased to lower values of similar to 0.75 during the relatively clean condition while it increased up to similar to 0.86 during polluted condition mainly owing to the increases of ammonium sulfate, ammonium nitrate, and organic mass by carbon's contributions to PM mass concentrations. Pollution episodes in Beijing were strongly related to wind speed and wind direction. Stagnant weather conditions with southerly wind and low wind speed accelerated the accumulation of the pollutants in Beijing, which led to severe haze. It has been found that high PM2.5/AOT (aerosol optical thickness) ratio of 228.2 mu g m(-3) was observed when air mass was transported from western or northern China while significantly lower PM2.5/AOT of 107.6 mu g m(-3) was observed when it was affected mostly by local air pollutants in Beijing.</P>
-
Jung, Jinsang,Lee, Dahee,Jeong, Hyeonjin,Lee, Sangil,Oh, SangHyub Elsevier 2018 Atmospheric environment Vol.178 No.-
<P><B>Abstract</B></P> <P>The long-range transport (LRT) of pollutants between countries in Northeast Asia is a serious issue. However, reliable quantification of LRT pollutants has not been performed due to a lack of clear evidence of the transport between countries. Hourly chemical composition of PM<SUB>2.5</SUB> (particulate matter with a diameter of ≤2.5 μm) was measured continuously at a suburban site in Daejeon, Korea during the Lunar New Year festival period to investigate the influence of firework/firecracker emissions from China over areas downwind subject to LRT. Elevated PM<SUB>10</SUB> (particulate matter with a diameter of ≤10 μm) and PM<SUB>2.5</SUB> mass concentrations were observed over the Korean Peninsula during the third day of the Lunar New Year festival (30 January 2017) when air masses originated from the northern part of China. Water-soluble potassium (K<SUP>+</SUP>), an indicator of both firework/firecracker and biomass burning, increased significantly during the third day of the Lunar New Year festival with an episode to non-episode ratio of 7.5, whereas no increase in levoglucosan, an indicator of biomass burning, was observed. Because firework/firecracker activities do not typically occur over the Korean Peninsula during the Lunar New Year festival, elevated K<SUP>+</SUP> indicates that haze plumes mixed with firework/firecracker emissions in China impacted the Korean Peninsula through the LRT. This study finds, for the first time, clear evidence of the LRT of pollutants between source and receptor countries in Northeast Asia under Asian continental outflow.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Haze caused by firework activities in China impacted on the Korean Peninsula. </LI> <LI> Elevated K<SUP>+</SUP> over the Korean Peninsula was attributed to firework emissions from China. </LI> <LI> This study finds clear evidence of the LRT of pollutants from China to Korea. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>
-
Jung, Jinsang,Lee, Hanlim,Kim, Young J.,Liu, Xingang,Zhang, Yuanhang,Gu, Jianwei,Fan, Shaojia Elsevier 2009 Journal of Environmental Management Vol.90 No.11
<P><B>Abstract</B></P><P>Optical and chemical aerosol measurements were obtained from 2 to 31 July 2006 at an urban site in the metropolitan area of Guangzhou (China) as part of the Program of Regional Integrated Experiment of Air Quality over Pearl River Delta (PRIDE-PRD2006) to investigate aerosol chemistry and the effect of aerosol water content on visibility impairment and radiative forcing. During the PRIDE-PRD2006 campaign, the average contributions of ammonium sulfate, organic mass by carbon (OMC), elemental carbon (EC), and sea salt (SS) to total PM<SUB>2.5</SUB> mass were measured to be 36.5%, 5.7%, 27.1%, 7.8%, and 3.7%, respectively. Compared with the clean marine period, (NH<SUB>4</SUB>)<SUB>2</SUB>SO<SUB>4</SUB>, NH<SUB>4</SUB>NO<SUB>3</SUB>, and OMC were all greatly enhanced (by up to 430%) during local haze periods via the accumulation of a secondary aerosol component. The OMC dominance increased when high levels of biomass burning influenced the measurement site while (NH<SUB>4</SUB>)<SUB>2</SUB>SO<SUB>4</SUB> and OMC did when both biomass burning and industrial emissions influenced it. The effect of aerosol water content on the total light-extinction coefficient was estimated to be 34.2%, of which 25.8% was due to aerosol water in (NH<SUB>4</SUB>)<SUB>2</SUB>SO<SUB>4</SUB>, 5.1% that in NH<SUB>4</SUB>NO<SUB>3</SUB>, and 3.3% that in SS. The average mass-scattering efficiency (MSE) of PM<SUB>10</SUB> particles was determined to be 2.2±0.6 and 4.6±1.7m<SUP>2</SUP>g<SUP>−1</SUP> under dry (RH<40%) and ambient conditions, respectively. The average single-scattering albedo (SSA) was 0.80±0.08 and 0.90±0.04 under dry and ambient conditions, respectively. Not only are the extinction and scattering coefficients greatly enhanced by aerosol water content, but MSE and SSA are also highly sensitive. It can be concluded that sulfate and carbonaceous aerosol, as well as aerosol water content, play important roles in the processes that determine visibility impairment and radiative forcing in the ambient atmosphere of the Guangzhou urban area.</P>
-
-
Impact of Siberian forest fires on the atmosphere over the Korean Peninsula during summer 2014
Jung, Jinsang,Lyu, Youngsook,Lee, Minhee,Hwang, Taekyung,Lee, Sangil,Oh, Sanghyub Copernicus GmbH 2016 Atmospheric Chemistry and Physics Vol.16 No.11
<P>Abstract. Extensive forest fires occurred during late July 2014 across the forested region of Siberia, Russia. Smoke plumes emitted from Siberian forest fires underwent long-range transport over Mongolia and northeast China to the Korean Peninsula, which is located ∼ 3000 km south of the Siberian forest. A notably high aerosol optical depth of ∼ 4 was observed at a wavelength of 500 nm near the source of the Siberian forest fires. Smoke plumes reached 3-5 km in height near the source and fell below 2 km over the Korean Peninsula. Elevated concentrations of levoglucosan were observed (119.7 ± 6.0 ng m−3), which were ∼ 4.5 times higher than those observed during non-event periods in July 2014. During the middle of July 2014, a haze episode occurred that was primarily caused by the long-range transport of emission plumes originating from urban and industrial complexes in East China. Sharp increases in SO42− concentrations (23.1 ± 2.1 µg m−3) were observed during this episode. The haze caused by the long-range transport of Siberian forest fire emissions was clearly identified by relatively high organic carbon (OC) ∕ elemental carbon (EC) ratios (7.18 ± 0.2) and OC ∕ SO42− ratios (1.31 ± 0.07) compared with those of the Chinese haze episode (OC ∕ EC ratio: 2.4 ± 0.4; OC ∕ SO42− ratio: 0.21 ± 0.05). Remote measurement techniques and chemical analyses of the haze plumes clearly show that the haze episode that occurred during late July 2014 was caused mainly by the long-range transport of smoke plumes emitted from Siberian forest fires. </P>
-
Jung, Jinsang,Yu, JeongAh,Lyu, Youngsook,Lee, Minhee,Hwang, Taekyung,Lee, Sangil Copernicus GmbH 2017 Atmospheric Chemistry and Physics Vol.17 No.8
<P>Abstract. Long-range transported (LRT) haze can affect the regional radiation budget and the air quality in areas downwind of the Asian continental outflow. Because in situ observations of spectral aerosol optical properties of the LRT haze are rare, an intensive characterization of aerosol optical properties is needed. This study characterized the spectral optical properties of the LRT haze and Asian dust originating from the Asian continent. Integrated chemical and optical measurements of aerosol particles were carried out in a downwind area of the Asian continental outflow (Daejeon, South Korea) during winter 2014. High concentrations of PM10 (particulate matter with a diameter ≤ 10 µm) and light scattering coefficients at 550 nm, σs, 550, were observed during a long-range transport (LRT) haze episode (PM10 = 163.9 ± 25.0 µg m−3; σs, 550 = 503.4 ± 60.5 Mm−1) and Asian dust episode (PM10 = 211.3 ± 57.5 µg m−3; σs, 550 = 560.9 ± 151 Mm−1). During the LRT haze episode, no significant change in the relative contribution of PM2. 5 (particulate matter with a diameter ≤ 2.5 µm) chemical components was observed as particles accumulated under stagnant atmospheric conditions (13-17 January 2014), suggesting that the increase in PM2. 5 mass concentration was caused mainly by the accumulation of LRT pollutants. On the other hand, a gradual decrease in Ångström exponent (Å) and a gradual increase in single scattering albedo (ω) and mass scattering efficiency (MSE) were observed during the stagnant period, possibly due to an increase in particle size. These results imply that a change in particle size rather than chemical composition during the stagnant period is the dominant factor affecting the aerosol optical properties. During the Asian dust episode, a low PM2. 5 ∕ PM10 ratio and Å(450∕700) were observed with average values of 0.59 ± 0.06 and 1.08 ± 0.14, respectively, which were higher than those during the LRT haze episode (0.75 ± 0.06 and 1.39 ± 0.05, respectively), indicating that PM2. 5 ∕ PM10 mass ratios and Å(450∕700) can be used as tracers to distinguish aged LRT haze and Asian dust under the Asian continental outflow. </P>
연관 검색어 추천
이 검색어로 많이 본 자료
활용도 높은 자료
