• Title/Summary/Keyword: Long range transport

Search Result 260, Processing Time 0.024 seconds

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
    • /
    • 2003.11a
    • /
    • pp.738-740
    • /
    • 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.

  • PDF

A Study on the Effect of Cumulus Parameterization and Microphysics on Ozone Simulations during Long-range Transport Process over Northeast Asia (동북아 장거리 수송 과정에서 적운 모수화 및 미세물리과정이 오존 모사농도에 미치는 영향 연구)

  • Kang, Jeong-Eon;Kim, Cheol-Hee
    • Journal of Korean Society for Atmospheric Environment
    • /
    • v.29 no.2
    • /
    • pp.135-151
    • /
    • 2013
  • This study has been carried out to analyze the sensitivity of ozone concentrations by employing different options of cumulus parameterization schemes (CPSs) and microphysics schemes in MM5 models. These sensitivity tests were applied to long-range transport case of higher ozone over Northeast Asia. Employed CPS schemes are Betts-Miller (BM), Grell (GR), Kain-Fritsch2 (KF2), Anthes-Kuo (AK), None scheme (grid scale physics only), and four microphysics used here are Simple ice, Reisner1, Reisner2, Schultz scheme in MM5. We chose two cases of high ozone long range transport case by employing both concentrations ozone level and backward trajectory model. The results showed that modeled ozone concentrations indicated about 10% differences among CPSs. Of the all options, GR and KF2 (for CPS), and Rersiner-1 and Resiner-2 (for microphysics) showed relatively good and stable variations against ensemble mean values. For both CPS and microphysics schemes, the difference of precipitation arising from different parameterization schemes was significant by itself, but the resultant ozone variations showed only marginal. But the cloud fraction differences arising from different parameterization schemes showed better correlation with ozone variations than precipitation differences, indicating that the photochemical ozone generation variations is more dominant by cloud fraction than wet removal process for high and long-ranged transported ozone cases over Northeast Asia.

Influences of Air Trajectories on the Variations of Carbon Monoxide in Major Cities in Korea for the Year of 1999 (1999년 기류의 이동궤적에 따른 우리나라 주요 도시의 일산화탄소 농도 변화)

  • 김영성;김영주;김진영
    • Journal of Korean Society for Atmospheric Environment
    • /
    • v.17 no.6
    • /
    • pp.451-461
    • /
    • 2001
  • Backward trajectories were calculated from five urban areas in Korea in 1999 in order to assess the effects of long-range transport on the air quality variations on an annual basis. The five areas selected were Seoul, Mokpo, Cheju, Pohang, and Kangnung, which are evenly distributed along the shoreline in Korea. Meteorological fields used in the work were prepared by the Korea Meteorological Administration using the RDAPS(Regional Data Assimilation and Prediction System) with grid spacing of 40 km and 12-h intervals(0000 and 1200 UTC). Upwind regions around the Korean Peninsula were divided into five sectors including the region to the northeast(I), northern China (II), southern China(III), the northwestern Pacific(IV), and Japan(V). The influence of air flow from these sectors on the variations of carbon monoxide concentrations in the selected areas was investigated. The results showed that the influences of Sectors II and III were persistent although some influences of adjacent sectors were observed according to the location of the areas. In general, the concentration of carbon monoxide tended to go up under the influence of Sectors II and III but tended to go down under the influence of Sector I. However, the influences of other sectors were rather mixed. The importance of the long-range transport was examined when the whole country was uniformly influenced by Sectors II and III with strong synoptic winds. The effects of long-range transport were large in Mokpo and Cheju, close to Sectors II and III, where the local emissions were considered small. The effects of local emissions were significant in Pohang and Seoul; such effect was more distinct in Pohang located farther from Sectors II and III.

  • PDF

Characteristics and Status of Persistent Organic Pollutants and Heavy Metals in Ambient Air (대기 중 잔류성 유기오염물질과 중금속의 특성과 현황)

  • 김영성
    • Journal of Korean Society for Atmospheric Environment
    • /
    • v.19 no.2
    • /
    • pp.113-132
    • /
    • 2003
  • In May 2001, the Stockholm Convention on Persistent Organic Pollutants (POPs) for phasing out and eliminating POPs was signed by 90 countries at the Diplomatic Meeting in Stockholm. In 1998, three years before the Convention, the protocols on POPs and heavy metals were adopted by the United Nations Economic Commission for Europe under the Convention on Long-Range Transboundary Air Pollution. Growing attention on POPs and heavy metals during the past 10 years is primarily due to their toxicity in minute quantities. POPs and some metal compounds are even more toxic because of their bioaccumulation potentials associated with a high lipid solubility. Furthermore, owing to their persistence and semi - volatility, they are widely distributed in the environment, traveling great distances on wind and water currents. Recent international cooperation to address POPs and heavy metals has focused on these issues. Long -range transport of those pollutants are particularly concerned since Korea is located downwind of prevailing westerlies from China. In this paper, a review is provided to assess the properties, sources, emissions, and atmospheric concentrations on POPs and heavy metals.

Numerical Simulation of Tracer Distribution during CAPTEX (CAPTEX 자료에 나타난 추적물 농도 분포의 수치 모사)

  • Kim, Seung-Bum;Lee, Tae-Young
    • Journal of Korean Society for Atmospheric Environment
    • /
    • v.10 no.E
    • /
    • pp.357-370
    • /
    • 1994
  • This paper introduces an Eulerian long- range transport model coupled with a mesoscale atmospheric model. The model has been applied to the simulation of tracer distribution during two cases of Cross Appalachian Tracer Experiment (CAPIEX). Meteorological fields are Predicted by CSU RAMS with four-dimensional assimilation and tracer transport is computed from an Eulerian dispersion model. The atmospheric model with a four-dimensional assimilation has produced meteorological fields that agree well with observation and has proved its high potential as a generator of meteorological data for a long-range transport model. The Present transport model Produces reasonable simulations of observed tracer transport although it was partially successful in the case with complicated structure in observed concentration. Model with Bott's 2nd-order scheme performs as well as that with Bott's 4th-order scheme and increased explicit horizontal diffusivity. Diagnosis of the model results indicates that the Present long-range transport model has a good potential as a framework for the acid deposition model with detailed cloud and chemical processes.

  • PDF

Environmental Distribution and Fate of Perfluorinated Compounds (PFCs) as Emerging POPs: Physico-Chemical Properties, Emission, Contamination Level, Inter-phase Distribution and Long-Range Transport (잠재적 POPs로서의 과불소화화합물의 환경 내 분포 및 거동: 물성, 환경 내 농도수준, 상 분배 및 장거리이동을 중심으로)

  • Kim, Seung-Kyu
    • Environmental Analysis Health and Toxicology
    • /
    • v.23 no.3
    • /
    • pp.143-164
    • /
    • 2008
  • Concern about perfluorinated compounds (PFCs) is growing nationally as well as globally. PFCs could be considered emerging POPs due to their environmentally persistent, bioaccumulative, and potentially harmful properties. Moreover. perfluoroalkylates (PFAs) such as PFOS and PFOA are reported to experience long-range transport (LRT) to the Arctic in spite of their low volatility and strong solubility. The possible pathways contributing to LRT have been proposed but are still in debate in combination with unclear source definition and uncertain physico-chemical properties. The environmental fate of PFCs is more complicated because of the presence of precursors that are degraded to PFAs and are extremely different from their daughters, PFAs. in physico-chemical properties. To what extent and through what pathways are human and wildlife exposed is determined by the environmental fate and distribution of PFCs. To define uncertainties in fate and distribution thus is critical to prevent erroneous policy and/or determination related with exposure and risk reduction. This article aimed to review controversy and/or uncertain issues for the environmental fate and distribution of PFCs and to prospect research topics necessary to dissolve uncertainties.

Source-Receptor Relationships of Transboundary Air Pollutants in East Asia Region Simulated by On-Line Transport Model

  • Jang, Eun-Suk;Itsushi Uno
    • Environmental Sciences Bulletin of The Korean Environmental Sciences Society
    • /
    • v.4 no.2
    • /
    • pp.111-116
    • /
    • 2000
  • Transboundary air pollution has recently become an area of increasing scientific interest and political concern as countries are receiving air pollutants from their neighbors. In order to gain a better understanding of the long-range transport processes of air pollutants and the source-receptor relationships among neighboring countries, an atmospheric transport model coupled with a RAMS(Regional Atmospheric Modeling System) model was applied to the East Asia region during the entire month of January 1993. The scalar transport option of the RAMS model was used to calculate special atmospheric constituents such as trace gases or aerosols. The sulfate production in clouds and rainwater and its removal processes by dry and wet deposition were considered. The sulfate budget from source regions to receptor regions was estimated by analysing the source-receptor relationships. When a specific receptor site revealed a sulfate value higher than the sulfate concentration based on its own source origin, this was taken to indicate long-range transport from another source region. The contribution ratio from various source region was calculated. The contribution ratio of dry and wet deposition was higher on the main continent of the East region. Furthermore, the high deposition amounts were identified on the west coast of Korea and the East China Sea.

  • PDF

The Vertical Distribution Patterns of Long Range Transported SO2 in Korea Peninsula (한반도 서해상으로 장거리 이동하는 SO2의 농도 및 연직분포 특징)

  • Han, J.S.;Ahn, J.Y.;Hong, Y.D.;Kong, B.J.;Lee, S.J.;Sunwoo, Y.
    • Journal of Korean Society for Atmospheric Environment
    • /
    • v.20 no.5
    • /
    • pp.671-683
    • /
    • 2004
  • This study was carried out to understand long-range transport of $SO_2$ using aircraft measurements for the identification of it's horizontal and vertical concentration and distribution pattern. Thirteen missions of aircraft measurements have been done around 37$^{\circ}$00'/124$^{\circ}$30' from October 1997 to November 2001. Concentrations of $SO_2$ was 1.5~2.0 ppb in the below mixing layer, 0.6~1.1 ppb in the above mixing layer. $SO_2$ was found to be relatively higher than marine background level, 0.08~0.2ppb, indicating the western coast being influenced by long-range transport except for the summer season. The vertical distribution of $SO_2$ was classified into 3 groups using its vertical sounding and meteorology pattern; the first is linear decay pattern, the second is exponential decay pattern, and the last is gaussian distribution pattern in the below mixing layer, 2 patterns of linear decay and gaussian distribution patterns in the upper layer. It is founded that vertical distribution pattern is strongly dependent on meteorological condition, for example atmospheric stability and predominant air flow.

Identification of Long-Range Transported Air Pollution Indicators over Northeast Asia (동북아시아 대기오염물질의 장거리 이동 지시자 선정 연구)

  • Park, Sin-Young;Kim, Cheol-Hee
    • Journal of Korean Society for Atmospheric Environment
    • /
    • v.29 no.1
    • /
    • pp.38-55
    • /
    • 2013
  • This study has been performed to select several indicators of long-range transport process that can be applied to the Northeast Asia. We first classified high air pollution days into long-range transport (LRT) dominant cases and the local emission dominant (LED) cases based on the synoptic meteorological variables including vorticity and geostrophic wind speed/direction at a geopotential level of 850 hPa. LRT cases were further categorized into two types: LRT-I type with air mass pathways from northern China and/or Mongolia, and LRT-II type from central and southern China. In each categorized case, we examined the difference of both measured aerosol optical properties of AERONET at two sites in western Korea, and the simulated characteristics of LRT process by MM5-CMAQ model. We contrasted LRT case with LED case, and then generated the LRT indicators applicable to Northeast Asia. The results showed that fine and coarse modes of LRT-II were relatively smaller than LED and LRT-I cases, respectively. Aerosol size distribution showed significantly higher concentration of fine-mode particle (mainly smoke or urban aerosols) in LED case in comparison with that of LRT groups (LRT-I, II), suggesting the amplitudes fine modes of LRT relative to LED as a possible LRT indicator. From the results of MM5-CMAQ modeling, we concluded that the conversion ratios for sulfur ($F_s$) were the most effective indicators of LRT cases, and the ratio of VOC to NOx and NOx to CO were found to be the second most effective indicators of LED case.