• Journal of the Korean earth science society
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• v.32 no.3
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• pp.276-293
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• 2011

In this study a modeling system consisting of Weather Research and Forecasting (WRF), Sparse Matrix Operator Kernel Emissions (SMOKE), the Community Multiscale Air Quality (CMAQ) model, and the CMAQ-Model of Aerosol Dynamics, Reaction, Ionization, and Dissolution (MADRID) model has been applied to estimate enhancements of $PM_{10}$ during Asian dust events in Korea. In particular, 5 experimental formulas were applied to the WRF-SMOKE-CMAQ (MADRID) model to estimate Asian dust emissions from source locations for major Asian dust events in China and Mongolia: the US Environmental Protection Agency (EPA) model, the Goddard Global Ozone Chemistry Aerosol Radiation and Transport (GOCART) model, and the Dust Entrainment and Deposition (DEAD) model, as well as formulas by Park and In (2003), and Wang et al. (2000). According to the weather map, backward trajectory and satellite image analyses, Asian dust is generated by a strong downwind associated with the upper trough from a stagnation wave due to development of the upper jet stream, and transport of Asian dust to Korea shows up behind a surface front related to the cut-off low (known as comma type cloud) in satellite images. In the WRF-SMOKE-CMAQ modeling to estimate the PM10 concentration, Wang et al.'s experimental formula was depicted well in the temporal and spatial distribution of Asian dusts, and the GOCART model was low in mean bias errors and root mean square errors. Also, in the vertical profile analysis of Asian dusts using Wang et al's experimental formula, strong Asian dust with a concentration of more than $800\;{\mu}g/m^3$ for the period of March 31 to April 1, 2007 was transported under the boundary layer (about 1 km high), and weak Asian dust with a concentration of less than $400\;{\mu}g/m^3$ for the period of 16-17 March 2009 was transported above the boundary layer (about 1-3 km high). Furthermore, the difference between the CMAQ model and the CMAQ-MADRID model for the period of March 31 to April 1, 2007, in terms of PM10 concentration, was seen to be large in the East Asia area: the CMAQ-MADRID model showed the concentration to be about $25\;{\mu}g/m^3$ higher than the CMAQ model. In addition, the $PM_{10}$ concentration removed by the cloud liquid phase mechanism within the CMAQ-MADRID model was shown in the maximum $15\;{\mu}g/m^3$ in the Eastern Asia area.

• Journal of the Korean earth science society
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• v.36 no.2
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• pp.158-170
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• 2015

This study evaluates the wind speed forecast near the surface layer using the Weather Research Forecasting with Large Eddy Simulation (WRF-LES) model in order to compare the planetary boundary layer (PBL) parameterization with the LES model in terms of different spatial resolution. A numerical simulation is conducted with 1-km and 333-m horizontal resolution over the Gangwon Province including complex mountains and coastal region. The numerical experiments with 1-km and 333-m horizontal resolution employ PBL parameterization and LES, respectively. The wind speed forecast in mountainous region shows a better forecast performance in 333-m experiment than in 1-km, while wind speed in coastal region is similar to the observation in 1-km spatial resolution experiment. Therefore, LES experiment, which directly simulates the turbulence process near the surface layer, contributes to more accurate forecast of surface wind speed in mountainous regions.

• Proceedings of the Korea Air Pollution Research Association Conference
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• 2008.10a
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• pp.400-401
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• 2008

• Proceedings of the Korea Air Pollution Research Association Conference
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• 2009.10a
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• pp.173-174
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• 2009

• Atmosphere
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• v.17 no.2
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• pp.115-123
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• 2007

The present study uses the GOES IR brightness temperature to examine the temporal and spatial variability of cloud activity over the region $25^{\circ}N-45^{\circ}N$, $105^{\circ}E-135^{\circ}E$ and analyzes the coherence of eastern Asian summer season rainfall in Weather Research and Forecast (WRF) model. Time-longitude diagram of the time period from June to July 2005 shows a signal of eastward propagation in the WRF model and convective index derived from GOES IR data. The rain streaks in time-latitude diagram reveal coherence during the experiment period. Diurnal and synoptic scales are evident in the power spectrum of the time series of convective index and WRF rainfall. The diurnal cycle of early morning rainfall in the WRF model agrees with GOES IR data in the Korean Peninsula, but the afternoon convection observed by satellite observation in China is not consistent with the WRF rainfall which is represented at the dawn. Although there are errors in strength and timing of convection, the model predicts a coherent tendency of rainfall occurrence during summer season.

• 한국신재생에너지학회:학술대회논문집
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• 2010.11a
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• pp.181.1-181.1
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• 2010

기후변화의 주요인이 되는 온실가스 감축을 목표로 화석연료를 대체하기 위한 대체 에너지 개발을 위한 많은 노력이 진행되고 있다. 풍력 에너지와 같은 신재생에너지는 이러한 하나의 해결 수단이 될 수 있으며 풍력 에너지 사업의 활성화를 위해서는 정확한 풍력 정보 제공이 우선이다. 풍력-기상자원지도는 풍력 발전에 유용한 정보 제공을 위한 목적으로 중규모 수치 모델을 이용하여 작성된다. 본 연구에서는 중규모 수치 모델의 정확도 향상을 위한 자료동화 방법으로써 Four-Dimensional Data Assimilation (FDDA) 방법을 이용한다. 풍력-기상자원지도는 공간분해능 1 km 해상도로 개발된다. 풍력-기상자원지도는 1998-2008년까지의 평균적인 상태에 대하여 모의를 하기 위하여 통계적인 방법으로 11년 기간의 평균과 유사한 기간을 선정하였다. 풍력-기상자원지도는 연 평균, 월 평균 풍속과 주 풍향, 주풍향 발생 비율 등의 정보를 제공한다. 우리나라 풍속의 평균 분포는 내륙 산악지역, 남해안, 제주도에서 강풍이 발생하며 주 풍향은 대체로 북서풍이다. 주 풍향의 발생비율은 산악 지역과 남 동해안에서 높아 풍력 발전의 최적지 정보를 제공한다. 1 km 해상도의 모델과 관측의 오차는 서해안 등의 해안지역보다 강원 산악지역에서 오차가 더욱 증가하였다. 이러한 산악 지역의 오차는 복잡한 지형에서는 1km 미만의 수 백 m 해상도 수치모의가 필요함을 지시한다. 따라서 본 연구에서는 WRF-LES 모형을 이용하여 333m 해상도의 기상자원지도를 개발한다. 333m 해상도의 자원지도 영역은 강원도 지역에 대하여 모의되었다. 333m 해상도의 풍속 분포는 1km 해상도의 풍속 분포와 비교하였을 때 풍속의 분포가 보다 세밀하게 표현되었다. 정량적인 검증을 하였을 때 관측소에 따라 차이는 있었으나 1km 해상도에서 과대 모의된 풍속의 분포가 현저히 개선이 되었으며, 시간적인 경향도 잘 일치함을 보였다.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.32 no.1B
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• pp.29-39
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• 2012

Climate change has been obtained researchers' interest, especially in water resources engineering to adjust current conditions to the new circumstance influenced by climate change. In this study, WRF-ARW will be evaluated the capability to estimate distributed precipitation using global weather information instead of the data from rainfall observatory or radar. Cheongmi watershed is selected and adopted to generate a distributed rainfall-runoff model using ModClark. The results from the distributed model with precipitation data from WRF-ARW and the lumped model using observed precipitation data were compared to the observed discharge values. The final results showed that the distributed model, ModClark generated similar pattern of hydrograph to the observations in terms of the time and amount of peak discharge. In addition, the trend of hydrograph from the distributed model presented similar pattern to the observations.

• Journal of the Korean earth science society
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• v.36 no.1
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• pp.90-108
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• 2015

The WRF-Chem model was applied to simulate the Asian dust event affecting the Korean Peninsula from 11 to 13 November 2010. GOCART dust emission schemes, RADM2 chemical mechanism, and MADE/SORGAM aerosol scheme were adopted within the WRF-Chem model to predict dust aerosol concentrations. The results in the model simulations were identified by comparing with the weather maps, satellite images, monitoring data of $PM_{10}$ concentration, and LIDAR images. The model results showed a good agreement with the long-range transport from the dust source area such as Northeastern China and Mongolia to the Korean Peninsula. Comparison of the time series of $PM_{10}$ concentration measured at Backnungdo showed that the correlation coefficient was 0.736, and the root mean square error was $192.73{\mu}g/m^3$. The spatial distribution of $PM_{10}$ concentration using the WRF-Chem model was similar to that of the $PM_{2.5}$ which were about a half of $PM_{10}$. Also, they were much alike in those of the UM-ADAM model simulated by the Korean Meteorological Administration. Meanwhile, the spatial distributions of $PM_{10}$ concentrations during the Asian dust events had relevance to those of both the wind speed of u component ($ms^{-1}$) and the PBL height (m). We performed a regressive analysis between $PM_{10}$ concentrations and two meteorological variables (u component and PBL) in the strong dust event in autumn (CASE 1, on 11 to 23 March 2010) and the weak dust event in spring (CASE 2, on 19 to 20 March 2011), respectively.

• Proceedings of the Korea Water Resources Association Conference
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• 2022.05a
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• pp.425-425
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• 2022

동아시아 지역은 몬순 영향으로 계절적인 수자원 변동성이 매우 크고 홍수 및 가뭄과 같은 수재해 피해가 빈번히 발생하고 추세이다. 본 연구에서는 동아시아의 수자원 관리에 활용하기 위해 수문 모형 중 하나인 WRF-Hydro (Weather Research and Forecast and Model Hydrological modeling extension package) 모형을 구축하였다. WRF-Hydro 모형은 미국 NCAR (National Center for Atmospheric Research)에서 개발된 커뮤니티형 고해상도 예측모델로 미국 등에서 활발히 사용되고 있으나, 동아시아 지역에 적용된 연구는 없다. 따라서 모형의 동아시아 적용 가능성에 대한 불확실성이 높다. 본 연구에서는 WRF-Hydro 모형을 0.25°의 공간해상도로 동아시아 대상으로 구축하였고, 기상 및 지면 특성과 유역자료를 활용한 머신러닝 방법으로 파라미터 보정을 시행하여 2006년부터 2015년까지 구동하였다. 머신러닝을 통해 지역특성이 고려된 WRF-Hydro 모형은 표면유출, 보수깊이, 표면 거칠기, 표면 기울기와 같은 매개변수를 보정하였다. 모형 평가를 위해 GRDC (Global Runoff Database Center (GRDC), GLDAS (Global Land Data Assimilation System), ESA-CCI (European Space Agency Climate Change Initiative), MODIS (Moderate Resolution Imaging Spectroradiometer)에서 제공하는 관측 유출량, 토양수분, 증발산량을 비교, 분석하여 동아시아 적용 적절성에 대해 검토하였다.

• Korean Journal of Agricultural and Forest Meteorology
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• v.18 no.4
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• pp.307-319
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• 2016

A Land-Atmosphere Modeling Package (LAMP) for supporting agricultural and forest management was developed at the National Center for AgroMeteorology (NCAM). The package is comprised of two components; one is the Weather Research and Forecasting modeling system (WRF) coupled with Noah-Multiparameterization options (Noah-MP) Land Surface Model (LSM) and the other is an offline one-dimensional LSM. The objective of this paper is to briefly describe the two components of the NCAM-LAMP and to evaluate their initial performance. The coupled WRF/Noah-MP system is configured with a parent domain over East Asia and three nested domains with a finest horizontal grid size of 810 m. The innermost domain covers two Gwangneung deciduous and coniferous KoFlux sites (GDK and GCK). The model is integrated for about 8 days with the initial and boundary conditions taken from the National Centers for Environmental Prediction (NCEP) Final Analysis (FNL) data. The verification variables are 2-m air temperature, 10-m wind, 2-m humidity, and surface precipitation for the WRF/Noah-MP coupled system. Skill scores are calculated for each domain and two dynamic vegetation options using the difference between the observed data from the Korea Meteorological Administration (KMA) and the simulated data from the WRF/Noah-MP coupled system. The accuracy of precipitation simulation is examined using a contingency table that is made up of the Probability of Detection (POD) and the Equitable Threat Score (ETS). The standalone LSM simulation is conducted for one year with the original settings and is compared with the KoFlux site observation for net radiation, sensible heat flux, latent heat flux, and soil moisture variables. According to results, the innermost domain (810 m resolution) among all domains showed the minimum root mean square error for 2-m air temperature, 10-m wind, and 2-m humidity. Turning on the dynamic vegetation had a tendency of reducing 10-m wind simulation errors in all domains. The first nested domain (7,290 m resolution) showed the highest precipitation score, but showed little advantage compared with using the dynamic vegetation. On the other hand, the offline one-dimensional Noah-MP LSM simulation captured the site observed pattern and magnitude of radiative fluxes and soil moisture, and it left room for further improvement through supplementing the model input of leaf area index and finding a proper combination of model physics.