• 제목/요약/키워드: Atmospheric environmental condition

검색결과 254건 처리시간 0.031초

서울지역 미세먼지 고농도에 따른 천식사망자 사례일의 종관기상학적 분류 (Synoptic Meteorological Classification of the Days on Which Asthma Deaths Occurred Due to High PM10 Concentrations in Seoul)

  • 최윤정;박종길;정우식
    • 한국환경과학회지
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    • 제26권2호
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    • pp.159-172
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    • 2017
  • Asthma deaths in Seoul peaked on the third, fifth, and second days after the PM concentration exceeded the daily average concentration standard. We classified the synoptic meteorological conditions, based on the days involving such cases, into three categories. Type 1 included the meteorological condition likely to cause high air pollution concentrations in the leeward region, the dominant wind direction of which is the northwest. Type 2 included the meteorological condition likely to cause high air pollution concentrations due to the weak wind velocity under stable atmospheric conditions. Type 3 was when the passage low atmospheric pressure and the expansion of high atmospheric pressure occurred at the rear, indicating a meteorological condition likely to cause high air pollution, in certain regions. Type 1 occurred 11 times, with high concentrations of over $100{\mu}g/m^3$ being observed in the southeastern part of Seoul. Type 2 occurred 24 times, often accompanied by a PM concentration of $100{\sim}400{\mu}g/m^3$. Type 3 occurred 11 times, and was accompanied by several days of yellow dust that accounted for the highest concentrations.

미기상 특성에 따른 대기오염 농도분포에 관한 연구 (A Study on the Distribution of Air Pollutant Concentration According to Micrometeorological Characteristics)

  • 김유근;홍정혜;전병일
    • 한국환경과학회지
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    • 제3권1호
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    • pp.31-38
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    • 1994
  • The diffusion of the pollutants released into atmosphere is dependent on its chemical reaction, topography and micrometeorological characteristics. The purpose of the study is to investigate how much micrometeorological characteristics such as stability, wind speed and mixing height affect the diffusion of the air pollutants. For this purpose, this paper let 1) the basic theory be K-theory, 2) eddy diffusivity and wind speed be dependent on mixing height and stability, and 3) Grout method be used for numeric calculation. The result was 1) the more unstable condition, the higher mixing height and the higher wind speed we, the lower pollutants concentration appears, 2) the most intensive effect on the distribution of the pollutant concentration is the atmospheric stability.

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2016년 1월 폭설을 동반한 제주도 한파의 원인 재고찰 (Revisit the Cause of the Cold Surge in Jeju Island Accompanied by Heavy Snow in January 2016)

  • 한광희;구호영;배효준;김백민
    • 대기
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    • 제32권3호
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    • pp.207-221
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    • 2022
  • In Jeju, on January 23, 2016, a cold surge accompanied by heavy snowfall with the most significant amount of 12 cm was the highest record in 32 years. During this period, the temperature of 850 hPa in January was the lowest in 2016. Notably, in 2016, the average surface temperature of January on the Polar cap was the highest since 1991, and 500 hPa geopotential height also showed the highest value. With this condition, the polar vortex in the northern hemisphere meandered and expanded into the subtropics regionally, covering the Korean Peninsula with very high potential vorticity up to 7 Potential Vorticity Unit. As a result, the strong cold advection, mostly driven by a northerly wind, around the Korean Peninsula occurred at over 2𝜎. Previous studies have not addressed this extreme synoptic condition linked to polar vortex expansion due to the unprecedented Arctic warming. We suggest that the occurrence of a strong Ural blocking event after the abrupt warming of the Barents/Karas seas is a major cause of unusually strong cold advection. With a specified mesoscale model simulation with SST (Sea Surface Temperature), we also show that the warmer SST condition near the Korean Peninsula contributed to the heavy snowfall event on Jeju Island.

한우 및 젖소농장 발생 악취의 확산특성 연구 (A Study on Dispersion Characteristics of Odor from Hanwoo and Dairy Farms)

  • 김두환;하덕민;이재영;김희호;송준익
    • 한국축산시설환경학회지
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    • 제21권1호
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    • pp.1-8
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    • 2015
  • This study was conducted to investigate the dispersion prediction of odor from Hanwoo and dairy farms. Gaussian Plume model used in considering of farm size, wind velocity, atmospheric stability and threshold odor unit to prediction of odor dispersion based on the survey on current state of odor emission and control from 9 site of Hanwoo and 9 site of dairy farms. Farm size, wind velocity and atmospheric stability were affected the distance of odor dispersion, showed longer distance in cases of large farm, low wind velocity and stable atmospheric condition. We will suggestion the adjusted distance of odor dispersion according to farm size was estimated to 50~100 m in Hanwoo farm and 50~150 m in dairy farm when apply the 3OU, 5 m/s wind velocity and stable atmospheric condition.

양돈장 발생 악취의 확산특성 연구 (A Study on Dispersion Characteristics of Odor from Swine Farms)

  • 김두환;하덕민;이인복;최동윤;송준익
    • 한국축산시설환경학회지
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    • 제20권2호
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    • pp.41-48
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    • 2014
  • This study was conducted to investigate the dispersion prediction of odor from swine farms in Korea. Gaussian Plume model used in considering of farm size, wind velocity, atmospheric stability and threshold odor unit to prediction of odor dispersion based on the survey on current state of odor emission and control from 48 site of swine farms. Farm size, wind velocity and atmospheric stability were affected the distance of odor dispersion, showed longer distance in cases of large farm, low wind velocity and stable atmospheric condition. We will suggestion the adjusted distance of odor dispersion according to farm size was estimated to 180 m in small farm and 320 m in large farm when apply the 3 OU, 5 m/s wind velocity and stable atmospheric condition.

부산광역시 대기환경 파악에 활용가능한 도시대기환경지도 작성에 관한 연구 (The Study on Establishment of the Urban Atmospheric Environment Map for Analysis of Atmospheric Environment in Busan Metropolitan City)

  • 김민경;정우식;이화운
    • 한국환경과학회지
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    • 제24권6호
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    • pp.807-817
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    • 2015
  • In this study the urban atmospheric environment map in Busan was made and it consist of the atmospheric environment element map and the atmospheric environment analysis map. The atmospheric environment element map covered the topography, the urban climate, the air pollutant emission, ozone and PM10 concentrations in Busan and the atmospheric environment analysis map included the thermal environment and the wind flow by using WRF meteorological numerical simulation. The meteorological elements from 2007 to 2011 in Busan were used in this study. As a result, in the center of Busan and Buk-gu along to the Nakdong river was the temperature high. To analyze the air flow of Busan 3 clusters depending on the wind direction were extracted with the cluster analysis. The results of the analysis on the detailed wind field of each cluster showed that the weak ventilation could be happened locally at the specific meteorological condition.

입력변수의 조건에 따른 대기확산모델의 민감도 분석 (Sensitivity Analysis of the Atmospheric Dispersion Modeling through the Condition of Input Variable)

  • 정진도;김장우;김정태
    • 한국환경과학회지
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    • 제14권9호
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    • pp.851-860
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    • 2005
  • In order to how well predict ISCST3(lndustrial Source Complex Short Term version 3) model dispersion of air pollutant at point source, sensitivity was analysed necessary parameters change. ISCST3 model is Gaussian plume model. Model calculation was performed with change of the wind speed, atmospheric stability and mixing height while the wind direction and ambient temperature are fixed. Fixed factors are wind direction as the south wind(l80") and temperature as 298 K(25 "C). Model's sensitivity is analyzed as wind speed, atmospheric stability and mixing height change. Data of stack are input by inner diameter of 2m, stack height of 30m, emission temperature of 40 "C, outlet velocity of 10m/s. On the whole, main factor which affects in atmospheric dispersion is wind speed and atmospheric stability at ISCST3 model. However it is effect of atmospheric stability rather than effect of distance downwind. Factor that exert big influence in determining point of maximum concentration is wind speed. Meanwhile, influence of mixing height is a little or almost not.

Improvement of Field Calibration of a Transmissometer for Visibility Measurement

  • Kim Kyung W.;Kim Young J.
    • Journal of Korean Society for Atmospheric Environment
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    • 제21권E2호
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    • pp.49-56
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    • 2005
  • A long-path transmissometer is one of the optical instruments widely used to measure atmospheric light extinction coefficient without enclosing a light beam and perturbing aerosols. Over the past two decades, a number of measurements have been carried out using the long-path transmissometer manufactured by OPTEC, Inc. Calibration of the transmissometer should be performed when any component of the transmissometer system is interchanged or installation condition is changed. For a better calibration of the transmissometer, application of a modified calibration method for the existing neutral density (ND)-filter method was recommended for the computation of the atmospheric transmittance using model MODTRAN 4 in this study. It was revealed that the measured light extinction coefficient from the transmissometer which was calibrated using the existing ND-filter method could be overestimated due to the assumption of the atmospheric transmittance suggested by OPTEC, Inc. The uncertainty of the measured light extinction coefficient from the transmissometer calibrated based on the modified ND-filter method was calculated to be approximately $13Mm^{-1}$.

대기안정도(大氣安定度)와 지형조건(地形條件)에 따른 풍향변동폭(風向變動幅)의 특성(特性) (Influence of Atmospheric Stability and Topography on the Wind Direction Fluctuations)

  • 김용국;이종범
    • 한국대기환경학회지
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    • 제8권2호
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    • pp.138-145
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    • 1992
  • Dependence of the standard deviation of wind direction fluctuations, ${\sigma}_{\theta}$, on atmospheric stability, averaging time and topography were analysed with the data measured at three sites, Youngjongdo beach of the Yellow Sea, Chuncheon basin and Doam-Dam valley. The results show that the mean value of ${\sigma}_{\theta}$ is large in complex terrain, the Doam-Dam site. It is notable that the large value of ${\sigma}_{\theta}$ at night is associated with the low wind speed and the strong stable condition. In order to study the long-period fluctuations of the wind direction, ${\sigma}_{\theta}$ for longer than 10 minutes averaging time was further analysed using the data obtained at the Chuncheon basin. At the averaging time shorter than 60 minutes, larger ${\sigma}_{\theta}$ is associated with longer averaging time in the strong stable condition. However, ${\sigma}_{\theta}$ was not affected significantly by wind speed and averaging time in neutral conditions. The results of the spectrum analysis for the time series data of wind direction showed that low-frequency fluctuations ranging from 10 to 60 minutes were dominated at the Chuncheon basin in strong stable condition.

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공기연소 분위기와 순산소 연소 분위기에서 입자 크기와 습도가 $CaCO_3$ 흡착제 입자의 반응특성에 미치는 영향 분석 (Analysis of the Effect of Particle Size and Humidity on Reaction Characteristics of $CaCO_3$ Sorbent Particle under Air and $O_2/CO_2$ Atmospheric Conditions)

  • 정성하;이강수;길상인;윤진한;김상수
    • 한국입자에어로졸학회지
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    • 제10권2호
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    • pp.75-82
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    • 2014
  • It is necessary to find out the reaction characteristics of $CaCO_3$ sorbent particles in air and $O_2/CO_2$ atmospheric conditions in order that an in-furnace desulfurization technique can be applied to oxy-fuel combustion system. In this study, rate of change of GMD(geometric mean diameter) and specific surface area of $CaCO_3$ sorbent particles reacted in DTF(drop tube furnace) experimental setup were analyzed to investigate the effect of particle size and humidity on the reaction characteristics of them. In air atmospheric condition, calcination process occurs actively within shorter residence times as the particle size increases. On the contrary, in $O_2/CO_2$ atmospheric condition, a calcination process is delayed as particle size increases. The increment of humidity accelerates calcination process in an air atmospheric condition and increase rate of calcination in an $O_2/CO_2$ atmospheric condition.