Evaluate Dry Deposition Velocity of the Nitrogen Oxides Using Noah-MP Physics Ensemble Simulations for the Dinghushan Forest, Southern China

Qi Zhang,Ming Chang,Shengzhen Zhou,Weihua Chen,Xuemei Wang,Wenhui Liao,Jianing Dai,ZhiYong Wu 한국기상학회 2017 Asia-Pacific Journal of Atmospheric Sciences Vol.53 No.4

There has been a rapid growth of reactive nitrogen (Nr) deposition over the world in the past decades. The Pearl River Delta region is one of the areas with high loading of nitrogen deposition. But there are still large uncertainties in the study of dry deposition because of its complex processes of physical chemistry and vegetation physiology. At present, the forest canopy parameterization scheme used in WRF-Chem model is a single-layer “big leaf” model, and the simulation of radiation transmission and energy balance in forest canopy is not detailed and accurate. Noah-MP land surface model (Noah-MP) is based on the Noah land surface model (Noah LSM) and has multiple parametric options to simulate the energy, momentum, and material interactions of the vegetation-soil-atmosphere system. Therefore, to investigate the improvement of the simulation results of WRF-Chem on the nitrogen deposition in forest area after coupled with Noah-MP model and to reduce the influence of meteorological simulation biases on the dry deposition velocity simulation, a dry deposition single-point model coupled by Noah- MP and the WRF-Chem dry deposition module (WDDM) was used to simulate the deposition velocity (Vd). The model was driven by the micro-meteorological observation of the Dinghushan Forest Ecosystem Location Station. And a series of numerical experiments were carried out to identify the key processes influencing the calculation of dry deposition velocity, and the effects of various surface physical and plant physiological processes on dry deposition were discussed. The model captured the observed Vd well, but still underestimated the Vd. The self-defect of Wesely scheme applied by WDDM, and the inaccuracy of built-in parameters in WDDM and input data for Noah-MP (e.g. LAI) were the key factors that cause the underestimation of Vd. Therefore, future work is needed to improve model mechanisms and parameterization.

지표 부근에서의 대기오염물질 건성 침적속도에 관한 모수화

이화운,박종길,장은숙,문난경 한국환경과학회 1994 한국환경과학회지 Vol.3 No.4

A predictive modal is demonstrated for gas removal rates from the atmosphere by dry deposition. Typical deposition velocities are complex functions of surface types, atmospheric stabilities, friction velocities, air pollutants, and so on. In this paper we simulated the calculation of dry deposition velocities near the earth surfaces, simultaneously we estimated real dry deposition velocities using the previous simulation. The measurement taken over a deciduous forest by Padro et al.(1988) were used to verify this model. In the comparison of the value of deposition velocity between numerical computation and observation, there are partially overestimations and underestimations between them, but we can speak that they are in a good accordance.

공기역학적 저항 모수화에 따른 오존의 건성침적속도 비교

이화운,문난경,노순아 한국환경과학회 2002 한국환경과학회지 Vol.11 No.7

The aerodynamic resistance(R_a) to vertical transfer in the surface boundary layer can be formulated in terms of the friction velocity, height of observation, vertical heat flux and surface roughness. Unlike previous studies which focused on the role of R_c, present study perform additional tests using a variety of R_a, formulae. Several R_a formulations available in the literature, suitable for unstable conditions, were tested for their influence on the dry deposition velocity. The canopy resistance(R_c) determines the shape of the diurnal pattern, while a small amplitude diurnal cycle in V_d was attributed to the aerodynamic resistance. The aerodynamic resistance is the major contributor to the formation of spikes in nighttime and R_a is relatively important at night because the canopy resistance is smaller. All formulations show similar diurnal cycle and yield good agreement with the observations. Although present V_d formulations are suitable for numerical air quality models, the research must continue for further improvements in resistance parametrizations.

지표면 특성을 고려한 부산지역의 건성침적속도 예측

문난경,이화운 한국환경과학회 2002 한국환경과학회지 Vol.11 No.9

Land-use types should be included in air pollutant diffusion model because a complex mixture of various land-use patterns with computational grid can make errors in calculation of several parameters. However, the air pollutant diffusion model has generally been treated with a uniform component with land-use type in each mesh because of the complexity of the simulation. This study presents a numerical simulation of the horizontal distribution of O_3 dry deposition velocity during summertime in Busan metropolitan city. The calculation of the meteorological field was conducted using the land cover data. Simulation has been performed by the following two scenarios : (1) one with current land cover data, and (2) the other with only land and sea for the surface characteristics. The results from each scenario reveals considerable differences on the meteorological fields and these differences can cause changes in the calculation values of O_3 deposition velocity.

군산지역 강하먼지의 침착량 및 건식 침착속도 추정

김성천 한국환경보건학회 2003 한국환경보건학회지 Vol.29 No.5

From Septemper 1997 to August 1999, dustfall samples were collected to calculate deposition of dustfall and metallic elements(e.g. Zn, Cd, Cr, Pb, and Fe) at four different sites : industrial, commercial, residental and Kunsan National University site at Kunsan in Korea. Significant differences of the deposition metallic elements were obsered in two stages of yellow sand: first stage is in Spring 1998, and the second is winter, 1998 and 1999. Deposition flux of dustfall and Zn, Cr and Fe was high in the first stage, but was not high in the second stage. Differences of regional and seasonal flux were also apparent. For the deposition flux of Cd and Fe was commercial > industrial > residental site, while that of Zn, Cd and Pb was industrial > residental > commercial site. Calculated water soluble ratio were 0.47 for residental, 0.42 for commercial, 0.59 for industrial site. The results indicate that industrial site was more affected strongly by anthropogenic sources, than commercial site was mass fractions of metallic elements showed very semilar values at commercial and industrial site, which seems to be effects of similar source and geological location.

지표면의 종류에 따른 오존의 건성침적속도에 관한 수치모의

이화운,노순아,문난경 한국대기환경학회 2003 한국대기환경학회지 Vol.19 No.5

Ozone is an important atmospheric pollutant that is occurred in tropospheric chemical process and it also affects the human health and plants. For a correct application of abatement strategies for ozone, it is necessary to understand the factors that control atmospheric ozone removal by dry deposition processes. The present study investigates the numerical simulation of the dry deposition velocity(V_(d)) obtained from PNU/DEM(Pusan National University Deposition Model). PNU/DEM includes seasonal categories, meteorological factors, surface properties and land-use types and proposes for and accurate numerical computation. And, this study examines the ability of the PNU/DEM to compute V_(d) of ozone over water surfaces and evaluates PNU/DEM by comparing its estimated V_(d) to past observed V_(d) over water. The parametrization was found to yield V_(d) values generally in good agreement with the observations for the deciduous forest and the coniferous forest. Ozone is removed slowly at wet surface of water due to its low water solubility. Therefore V_(d) values over water were lower than V_(d) values over the other surfaces. Comparison of PNU/DEM simulated V_(d) values to observations of ozone V_(d) that have been reported in the literature implies that PNU/DEM produces realistic results.

Gas/Particle Level and Dry Deposition Flux of Atmospheric PCBs

Yeo, Hyun-Gu,Park, Ki-Chul Korean Society of Environmental Health 2003 한국환경보건학회지 Vol.29 No.4

Atmospheric samples were conducted from September 2001 to July 2002 with GPS-l PUF sampler in rural site to concentration distributions of gas/particle PCBs and to calculate dry deposition flux of PCBs. $\Sigma$PCBs concentrations of gas/particle PCBs were 59.29$\pm$48.83, 6.56$\pm$6.59 pg/㎥, respectively. Gas contribution (%) of total PCBs (gas + particle) was 90% which existed gas phase in the atmosphere. The particle contribution (%) of PCB congeners increased relatively more of the less volatile congeners with the highest chlorine number. The correlation coefficients (r) between total PCBs and temperature ($^{\circ}C$) showed negative correlation in - 0.62 (p<0.0l) for particle phase, positive correlation in 0.63 (p<0.01) for gas phase. In other word, particle phase PCBs is enriched in colder weather which could be due to greater in corporation of condensed gas phase at low temperature. The calculated dry deposition of total PCBs (gas + particle) was 0.008, 0.008 $\mu\textrm{g}$ $m^{-2}$ da $y^{-l}$ which showed maximum dry deposition flux in December, minimum data in July Bs in the atmosphere. The calculated dry deposition fluxes of total PCBs were influenced by particle phase PCBs even though PCBs in the atmosphere were present primarily in the gas phase.e.

A Preiminary Design of Two-Layer Deposition Model on the sea near Cheju Island

이기호 제주대학교 해양과환경연구소 1998 해양과환경연구소 연구논문집 Vol.22 No.-

Dry Deposition Velocities of Trace Metals in Saraburi, Thailand

Sorn SUWANNACHOT,Warawut SUADEE,Patsiri SRIVIENG 대한환경공학회 2019 대한환경공학회 학술발표논문집 Vol.2019 No.-

탄성파를 통한 시료성형방법에 따른 모래 전단거동특성 평가

유진권(Jinkwon Yoo),박두희(Duhee Park) 한국지반환경공학회 2014 한국지반환경공학회논문집 Vol.15 No.5

경제적, 기술적인 이유에서 실내시험을 위한 in situ 상태 그대로의 현장 모래 시료를 채취하는 것은 매우 어렵다. 따라서 현장과 유사한 상태의 시료 조성을 위한 다양한 시료 재성형 방법이 제시되었으며, 연구 목적에 따라 적합하다고 판단되는 시료성형방법이 다양하게 적용되고 있다. 본 논문에서는 모래의 시료 재성형 시 널리 이용되고 있는 습윤다짐법, 건조낙사법, 그리고 건조퇴적법을 적용하여 동일한 상대밀도로 시료를 조성한 후, 일정한 구속압 조건에서 압밀배수전단 시험을 수행하였다. 또한 자체제작을 통해 시료의 상?하부 캡에 압전소자를 설치하여 압밀 종료 시점과 전단과정에서의 탄성파 속도를 측정함으로써 시료 재성형방법 및 상대밀도에 따른 오타와 모래에서의 거동 특성 및 전단거동 시의 탄성파 속도의 변화 경향을 분석하였다. 분석 결과, 시료 조성방법에 따라 전단과정에서 모래의 거동에는 차이가 발생할 수 있는 것으로 나타났으며, 전단과정 시 전단파 속도는 체적 변화양상과 동일한 경향을 보이는 것으로 나타났다. For economic and technical reasons, it is difficult to obtain high quality undisturbed cohesionless samples, hence most researchers rely on preparing remolded and reconstituted representative samples of sandy soils. In this study, moist tamping, air pluviation, and dry deposition methods were applied to make remolded samples at similar relative densities. A series of isotropically consolidated drained tests were conducted with accompanied by measured elastic wave velocities in order to evaluate a difference between sample preparation methods and relative densities. For the elastic wave velocity measurements, piezoelectric elements were installed on the top and bottom cap of the triaxial device. The results showed that soil behavior relies on sample preparation methods, and that the trend of shear wave velocity was the same with volumetric strain behavior.