• Title, Summary, Keyword: Asian dust

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The Analysis of the Weather Characteristics by Source Region of the Asian Dust Observed in South Korea (한국에 출현한 황사의 발원지별 기상 특성 분석)

  • Kim, Sunyoung;Lee, Seungho
    • Journal of the Korean Geographical Society
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    • v.48 no.2
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    • pp.167-183
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    • 2013
  • This paper aimed to investigate the Asian dust source region and climatic condition of source region by the case of Asian dust in south Korea. In order to analyze the weather condition of source region, observed the Asian dust days data and weather data in China were used. The Asian dust days originating from inner-Mongolia were the most frequent. The Asian dust days originating from all the source regions except Loess plateau were increased recently and occurred over the country. In case of Loess plateau, the frequency of the Asian dust days in 1960s was the highest and only the southern region of the south Korea was mostly affected. The relationship between the Asian dust days of Korea and climatic factors of spring and April of source region was significant. The relationship between the Asian dust days originating from the inner Mongolia and sea level pressure of April and relative humidity of spring was negative. The Asian dust days from Gobi had positive relationship with wind gust days and negative relationship with sea level pressure in April. The Asian dust days from Manchuria had negative relationship with precipitation and sea level pressure in April. The Asian dust days from Loess plateau had positive relationship with maximum wind speed and negative relationship with sea level pressure in April.

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Infrared Spectral Signatures of Dust by Ground-based FT-IR and Space-borne AIRS (지상 및 위성 고분해 적외스펙트럼 센서에서 관측된 황사 특성)

  • Lee, Byung-Il;Sohn, Eun-Ha;Ou, Mi-Lim;Kim, Yoon-Jae
    • Atmosphere
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    • v.19 no.4
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    • pp.319-329
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    • 2009
  • The intensive dust observation experiment has been performed at Korea Global Atmosphere Watch Center (KGAW) in Anmyeon, Korea during each spring season from 2007 to 2009. Downward and upward hyper-spectral spectrums over the dust condition were measured to understand the hyper-spectral properties of Asian dust using both ground-based Fourier Transform Infrared Spectroscopy (FT-IR) and space-borne AIRS/Aqua. To understand the impact of the Asian dust, a Line-by-Line radiative transfer model runs to calculate the high resolution infrared spectrum over the wave number range of $500-500cm^{-1}$. Furthermore, the radiosonde, a $PM_{10}$ Sampler, a Micro Pulse Lidar (MPL), and an Aerodynamic Particle Sizer (APS) are used to understand the vertical profile of temperature and humidity and the properties of Asian dust like concentration, altitude of dust layer, and size distribution. In this study, we found the Asian dust distributed from surface up to 3-4 km and volume concentration is increased at the size range between 2 and $8{\mu}m$ The observed dust spectrums are larger than the calculated clear sky spectrums by 15~60K for downward and lower by around 2~6K for upward in the wave number range of $800-1200cm^{-1}$. For the characteristics of the spectrum during the Asian dust, the downward spectrum is revealed a positive slope for $800-1000cm^{-1}$ region and negative slope over $1100-1200cm^{-1}$ region. In the upward spectrum, slopes are opposed to the downward one. It is inferred that the difference between measured and calculated spectrum is mostly due to the contribution of emission and/or absorption of the dust particles by the aerosol amount, size distribution, altitude, and composition.

A Method for Identifying Source Regions of Asian Dust Using the Long-range Transport Model and Satellite Images

  • Goto, Takeshi;Kawaguchi, Kazuo;Kusaka, Takashi
    • Proceedings of the KSRS Conference
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    • pp.738-740
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    • 2003
  • A method for identifying the released region and time of Asian dust using the long-range inverse transport model that traces the wind field in the backward direction from positions where Asian dust was observed is described. Initial conditions for the inverse transport simulation were obtained from the time variation of the density distribution of the suspended particulate matter (SPM) in the air measured at various places in Japan. Based on a concentration of trajectories of the air mass computed by the inverse transport model, the source region of Asian dust clouds observed at meteorological stations in Japan on March 17 to 18, 2002 was estimated. As a result, it was found that dust particles were released at about 6h on March 15 in the neighborhood of Inner Mongolian Autonomous Region.

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Public Perceptions of the Risk of Asian Dust Storms in Seoul and its Metropolitan Area (황사에 대한 수도권 거주 성인의 위해도 인식 조사)

  • Im, Hyoung-June;Ha, Mi-Na;Lee, Sang-Gyu;Hwang, Seung-Sik;Ha, Eun-Hee;Cho, Soo-Hun;Kwon, Ho-Jang
    • Journal of Preventive Medicine and Public Health
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    • v.39 no.3
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    • pp.205-212
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    • 2006
  • Objectives: In spite of the recent increased concern for Asian dust storms, there are few studies concerning how dangerous the general public recognizes these dust storms to be. This study examined the public's perceptions of the risk of the Asian dust storms and also the source of the information concerning the risk. Methods: A telephone interview survey using a standardized questionnaire was done for the adults living in Seoul and its metropolitan area from May 15th, 2003 to May 16th, 2003. The contents of the questionnaire were the sociodemographic characteristics, the perceptions of risk to the Asian dust storms, and the coping strategy of the study participants. Results: The study participants get their information on Asian dust storms mainly from TV newscasts and they have a good knowledge of them. They regard it as one of the most dangerous health risks, along with dioxin. They think that it is associated with allergic rhinitis, conjunctivitis and bronchial asthma, etc. Of the 500 study participants, 201 (40.2%) persons suffered bodily discomforts during the Asian dust storm period. Conclusions: Although there are uncertainties about the health risks of Asian dust storms, the public thinks these dust storms are very dangerous to health in many ways This negative perception will not disappear easily. To fill the gap of the public's perceptions of the risk and the objective evidence of its health effects, more studies about its health effects and the methods to reduce exposure are required.

Effects of the Severe Asian Dust Events on Daily Mortality during the Spring of 2002, in Seoul, Korea (2002년 봄 서울 지역에 발생한 심한 황사가 일별 사망에 미치는 영향)

  • Hwang, Seung-Sik;Kwon, Ho-Jang;Cho, Soo-Hun
    • Journal of Preventive Medicine and Public Health
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    • v.38 no.2
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    • pp.197-202
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    • 2005
  • Objectives: During the spring of 2002, an unprecedented 2 Asian dust events were experienced in Seoul. On those days, the $PM_{10}$ was surprisingly increased, with daily $PM_{10}$ averages exceeding $600\;and\;700{\mu}g/m^3$ on March 21 and April 8, respectively. Accordingly, public concern relating to the possible adverse health effects of these dust events has increased, as the dust arrives in Korea after having flown over heavily industrialized eastern China. We investigated the effects of these Asian dust events on the mortality during the spring of 2002, in Seoul, Korea. Methods: The total number of deaths per day during the spring of 2002 in Seoul was extracted form the mortality records of the National Statistical Office. We constructed 14 Asian dust days (March 17-March 23, April 7-April 13) and 42 control days during the 56 day study period (March 3-April 27) with respect to the days of the week. The daily average numbers of deaths between the Asian dust and control days were analyzed, with adjustment for meteorological variables and pollutants. Results: The daily PM10 average during the Asian dust weeks was $295.2{\mu}g/m^3$, which was significantly higher than during the control days (p<0.001). The daily average number of deaths from all causes during the Asian dust days was 109.9; 65.6 for those aged 65 years and older, 6.7 from respiratory causes (J00-J99) and 25.6 from cardiovascular causes (I00-I99). The estimated percentage increases in the rate of deaths were 2.5% (95% CI=-5.0-10.6) from all causes; 2.2% (95% CI=-7.4-12.8) for those aged 65 years and older, and 36.5% (95% CI=0.7-85.0) from respiratory causes, but with a 6.1% (95% CI=-19.7-9.7) decrease in deaths from cardiovascular causes. Conclusion: The Asian dust events were found to be weakly associated with the risk of death from all causes. However, the association between dust events and deaths from respiratory causes was stronger. This suggests that persons with advanced respiratory diseases may be susceptible to Asian dust events.

The Characteristics Asian Dust Observed in Japan Deflecting the Korean Peninsula (2010. 5. 22.-5. 25.) (한반도를 돌아 일본에서 관측된 황사의 특징 (2010년 5월 22일-5월 25일))

  • Ahn, Bo-Young;Chun, Young-Sin
    • Journal of the Korean earth science society
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    • v.32 no.4
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    • pp.388-401
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    • 2011
  • Asian dust was observed a total of 66 times in the springtime during the period from 2002 to 2010, with 26 cases in March, 23 cases in April and 17 cases in May. This study investigates a Asian dust episode that occurred during the period from 22 to 25 May 2010, based on synoptic weather patterns, wind vector at 850 hPa, relative humidity at 1000 hPa, Jet streams and wind vector at 300 hPa, PM10 concentration in Korea and satellite imagery. In this case, Asian dust originated on 22 May along the rear of a developing low pressure system in Mongolia. The Asian dust was then transported southeastward and bypassed the Korea peninsula from 23 to 24 May, before reaching Japan on 25 May. Jet streams on 24 May bypassed the Korean peninsula and induced the development of a surface low pressure centered over the peninsula. The resulting air flow was critical to the trajectory of the Asian dust, which likewise bypassed the Korean peninsula. 72-hour backward trajectory data reveal that the Shandong Peninsula and the East China Sea were the points of origin for the air flows that swept through the Japanese sites where Asian dust was observable to the naked eay. The Asian dust pathway is ascertained by horizontal distribution of the Asian dust of RGB imagery from MODIS satellites which captured the Asian dust moving over the Shandong Peninsula, the East China Sea, and northwest of the Kyushu region in Japan. Since the synoptic pattern and the transport way of the Asian dust case are far from typical ones, which Asian dust forecasting technique has long been based on, this study can be good example of exceptional Asian dust pattern and it will be used for more accurate Asian dust forecasting.

Study of Methodology for Estimating PM10 Concentration of Asian Dust Using Visibility Data (시정자료를 이용한 황사의 미세먼지 농도추정 방법 연구)

  • Lee, Hyo-Jung;Lee, Eun-Hee;Lee, Sang-Sam;Kim, Seungbum
    • Atmosphere
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    • v.22 no.1
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    • pp.13-28
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    • 2012
  • The $PM_{10}$ concentration data is useful for indentifying intensity and a transport way of Asian dust. However, it is difficult to identify them properly due to the limited spatial resolution and coverage. Therefore, a methodology to estimate $PM_{10}$ concentration using visibility data obtained from synoptic observation was developed. To derive the converting function, correlation between visibility and $PM_{10}$ concentration is investigated using visibility and $PM_{10}$ concentration data observed at 20 stations in Korea from 2005 to 2009. To minimize bias due to atmospheric moisture, data with higher relative humidity over a critical value were eliminated while deriving $PM_{10}$-visibility relationship. As a result, an exponentially decreasing function of visibility is obtained under the condition that relative humidity is less than 82%. Verification of the visibility converting function to $PM_{10}$ concentration was carried out for the dust cases in 2010. It was found that spatial distributions of $PM_{10}$ calculated by visibility are in good agreement with the observed $PM_{10}$ distribution, especially for the strong dust cases in 2010. And correlation between the derived and observed $PM_{10}$ concentration was 0.63. We applied the function to obtain distributions of $PM_{10}$ concentration over North Korea, in which concentration data are not available, and compared them with satellite derived dust index, IODI distributions for dust cases in 2010. It is shown that the visibility function estimates quite similar patterns of dust concentration with IODI image, which suggests that it can contribute for prediction by indentifying transport route of Asian dust.

Laboratory-scale Experiment and Model Calculation on the Washout Mechanism of Asian Dust Particles

  • Ma, Chang-Jin;Kim, Ki-Hyun
    • Asian Journal of Atmospheric Environment
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    • v.7 no.3
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    • pp.161-168
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    • 2013
  • In this study, an investigation was conducted to assess the washout mechanism of Asian dust particles through both laboratory-scale experiment and model calculation. To artificially simulate Asian dust particle, $CaCO_3$ particles were generated inside an experimental chamber. They were then scavenged by the artificial rain drops. The abundant $CaCO_3$ particles scavenged on a rain drop were successively identified by SEM observation. The concentrations of Ca in residual $CaCO_3$ particles on individual droplet were quantified by PIXE analysis. There was a tendency toward a high accumulation of Ca on a relatively small drop (e.g., <1.0 mm diameter). It is thus suggested that smaller rain drops can effectively scavenge a significant amount of Asian dust particles in ambient atmosphere. The numerical estimation can account for 92.1% and 83.2% of Ca that were measured in small (<1.0 mm diameter) and large (>2.0 mm diameter) size drops, respectively.

Estimation of the Light Absorption Contribution for Asian Dust and Polluted Particles at Gosan, Jeju during the Asian Dust Episode in the Spring 2011 (2011년 봄 황사시기 제주도 고산에서의 황사와 오염입자의 광흡수 기여도 산정)

  • Lee, Si-Hye;Kim, Sang-Woo;Yoon, Soon-Chang
    • Journal of Korean Society for Atmospheric Environment
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    • v.28 no.4
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    • pp.411-422
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    • 2012
  • Ground-based in-situ measurements of aerosol optical properties at Gosan climate observatory have been analyzed to investigate the optical contribution of Asian dust and polluted particles on light absorption in springtime 2011. During the Asian dust episode, the contribution of Asian dust particle to aerosol absorption coefficient estimated about 45% at 370 nm and about 23% at 520 nm. Especially, black carbon in dust plume contributes about 48% to aerosol light absorption at 520 nm since the airmass are transported from the Gobi and inner Mongolia deserts, and this airmass comes across the northeastern coast of China, near the Shandong Peninsula. In pollution case, the contributions of dust particle and black carbon to aerosol absorption coefficient estimated about 41% and 11% at 370 nm, respectively. However, pollution case shows the highest light absorption of 48% for brown carbon at 370 nm, which indicates the significantly high mass concentration of organic carbon ($6.3{\pm}2.2{\mu}g\;m^{-3}$) in pollution plume can contribute to the increase of light absorption at near-UV spectral region.

Concentration Characteristics and Health Effect Assessment of Atmospheric Particulate Matters During Asian Dust Storm Episodes (황사 에피소드 발생시 대기먼지의 농도 특성과 인체 영향)

  • Kang, Gong-Unn
    • Journal of Environmental Health Sciences
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    • v.35 no.1
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    • pp.21-35
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    • 2009
  • The Asian dust storms which originated in the deserts of Mongolia and China transported particles to Korea and led to a high concentration of atmospheric particulate matters (PM) of more than $1000{\mu}g/m^3$ throughout the country in the spring, of 2007. Public concern, in Korea, about the possible adverse effects of these dust events has increased, as these dust storms can contain various air pollutants emitted from heavily industrialized eastern China. The objectives of this study were to understand the concentration characteristics of PM as a function of particle size between the Asian dust storm episodes and non-Asian dust period and to consider the mass size distribution of PM in the Asian dust storms and their water soluble ion species on the potential, possible effects on deposition levels in the three regions (nasopharyngeal, tracheobronchial, and alveolar) of the human respiratory system. The size distribution of PM mass concentration during the Asian dust storms showed a peak in the coarse particle region due to the long-range transport of soil particles from the deserts of Mongolia and China, which was identified by HYSPLIT-4 model for backward trajectory analysis of air arriving in the sampling site of Iksan. During the non-Asian dust period, there were two different types in PM size distribution: bimodal distribution when low concentrations of $PM_{2.5}$ were observed, while unimodal distribution having a peak in fine particle region when high concentrations of $PM_{2.5}$ were showed. This unimodal distribution with high concentrations of fine particulate and secondary air pollutants such as ${SO_4}^{2-}$, ${NO_3}^-$, ${NH_4}^+$ was found to be due to the long-range transport of air pollutants from industrialized eastern China. During the Asian dust storms, the mean concentrations of PM that can be deposited in the nasopharyngeal, tracheobronchial, and alveolar region were $128.8{\mu}g/m^3$, $216.5{\mu}g/m^3$, and $89.6{\mu}g/m^3$, respectively. During the non-Asian dust period, the mean concentrations of PM that can be deposited in the nasopharyngeal, tracheobronchial, and alveolar region were $8.4{\mu}g/m^3$, $9.5{\mu}g/m^3$ and $38.5{\mu}g/m^3$, respectively.