• 제목/요약/키워드: Atmospheric deposition

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도시지역의 국지순환과 침적현상에 관한 수치모의 (Numerical Simulation for Local Circulation of Urban Area and Deposition Phenomenon)

  • 이화운;오은주;노순아;반수진
    • 한국대기환경학회지
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    • 제19권6호
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    • pp.773-787
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    • 2003
  • There are variations in the temperature Held due to urban heat island and anthropogenic heating so that regional scale meteorological field is changed. Therefore we simulate and predict the regional climate change according to surface characteristics through regional meteorological model. This study investigates the regional meteorological field by urbanization that influences in local circulation system using CSU-RAMS and simulates dry deposition velocity (V$_{d}$) using PNU/DEM which includes surface characteristics (such as albedo, surface hydrology and rough-ness length etc.) with calculated meteorological field. During the summer, horizontal distributions of V$_{d}$ were simulated using CSU-RAMS and PNU/DEM at Busan metropolitan area. The estimated values of V$_{d}$ were larger in forest and agricultural areas than water areas since ozone with low water solubility is destroyed slowly at wet surface or water.water.

Mercury Exchange Flux from Two Different Soil Types and Affecting Parameters

  • Park, Sang-Young;Kim, Pyung-Rea;Han, Young-Ji
    • Asian Journal of Atmospheric Environment
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    • 제7권4호
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    • pp.199-208
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    • 2013
  • Mercury exchange fluxes between atmosphere and soil surface were measured in two different types of soils; lawn soil (LS) and forest soil (FS). Average Hg emission from LS was higher than from FS although the soil Hg content was more than 2 times higher in forest soil. In LS, Hg emissions were much greater in warm season than in cold season; however, deposition was dominant in FS during warm season because of leafy trees blocking the solar radiation reaching on the soil surface. In both LS and FS, Hg fluxes showed significantly positive correlations with UV radiation and soil surface temperature during cold season. In addition, it was observed that emission showed positive correlation with UV radiation and soil temperature while there was negative relationship between deposition and UV radiation.

Creation of Diamond/Molybdenum Composite Coating in Open Air

  • Ando, Yasutaka;Tobe, Shogo;Tahara, Hirokazu
    • 한국분말야금학회:학술대회논문집
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    • 한국분말야금학회 2006년도 Extended Abstracts of 2006 POWDER METALLURGY World Congress Part2
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    • pp.1313-1314
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    • 2006
  • For improvement of wear resistance property of atmospheric thermal plasma sprayed molybdenum (Mo) coating, diamond deposition on the atmospheric plasma sprayed molybdenum coating by the combustion flame chemical vapor deposition (CFCVD) has been operated. In this study, to diminish the thermal damage of the substrate during operation, a thermal insulator was equipped between substrate and water-cooled substrate holder. Consequently, diamond particles could be created on the Mo coating without fracture and peeling off. From these results, it was found that this process had a high potential in order to improve wear resistance of thermal sprayed coating.

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지표면 Wetness에 따른 오존의 건성침적속도 특성 (The Characteristics of the Dry Deposition Velocity for O3 regarding Surface Wetness)

  • 이화운;김유근;문난경
    • 한국환경과학회지
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    • 제12권4호
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    • pp.393-397
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    • 2003
  • It has been researched the relationship between deposition velocity and factors which could affect the deposition phenomena and deposition velocity also has been estimated fer several land-use types. The typical deposition velocities are complex functions of surface types, atmospheric stabilities, friction velocities, air pollutants and so on. The canopy resistance is major contribution to the model's total resistance for O₃. Canopy wetness is also an important factor to calculate deposition velocity. We considered the canopy wetness as canopy water content(CWC) in our Model. But, it is not easy to observe CWC over each land-use types. In this study, we use CWC observed by EMEFS(CANADA Environment Service, 1988) to examine the influence of CWC in estimation of 03 dry deposition velocity(V/sub d/) in summertime. The value of O₃ V/sub d/ range 0.2 ∼ 0.7 cm s/sup -1/ on dry surface and 0.01 ∼ 0.35 cm s/sup -1/ on wet surface in daytime.