Impacts of different urban canopy schemes in WRF/Chem on regional climate and air quality in Yangtze River Delta, China

Liao, Junjie; Wang, Tijian; Wang, Xuemei; Xie, Min; Jiang, Zhe; Huang, Xianyu; Zhu, Jialei

doi:10.1016/j.atmosres.2014.04.005

Cited by 109 publications

(89 citation statements)

References 41 publications

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“…As a result, the model agreement with observations is not expected to be comparable with simulations that use FDDA. The annual mean MBs of T2 are larger than the suggested threshold values by Emery et al ([49]) but they are comparable or even better than the performance using MM5 (e.g., [44,50]) and WRF (e.g., [47,48,51,52]), and hence deemed acceptable.…”

Section: Observational Datasets and Evaluation Metricsmentioning

confidence: 87%

Application of an Online-Coupled Regional Climate Model, WRF-CAM5, over East Asia for Examination of Ice Nucleation Schemes: Part I. Comprehensive Model Evaluation and Trend Analysis for 2006 and 2011

Chen

Zhang

Fan

et al. 2015

Climate

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Online-coupled climate and chemistry models are necessary to realistically represent the interactions between climate variables and chemical species and accurately simulate aerosol direct and indirect effects on cloud, precipitation, and radiation. In this Part I of a two-part paper, simulations from the Weather Research and Forecasting model coupled with the physics package of Community Atmosphere Model (WRF-CAM5) are conducted with the default heterogeneous ice nucleation parameterization over East Asia for two full years: 2006 and 2011. A comprehensive model evaluation is performed using satellite and surface observations. The model shows an overall acceptable performance for major meteorological variables at the surface and in the boundary layer, as well as column variables (e.g., precipitation, cloud fraction, precipitating water vapor, downward longwave and shortwave radiation). Moderate to large biases exist for cloud condensation nuclei over oceanic areas, cloud variables (e.g., cloud droplet number concentration, cloud liquid and ice water paths, cloud optical OPEN ACCESSClimate 2015, 3 628 depth, longwave and shortwave cloud forcing). These biases indicate a need to improve the model treatments for cloud processes, especially cloud droplets and ice nucleation, as well as to reduce uncertainty in the satellite retrievals. The model simulates well the column abundances of chemical species except for column SO2 but relatively poor for surface concentrations of several species such as CO, NO2, SO2, PM2.5, and PM10. Several reasons could contribute to the underestimation of major chemical species in East Asia including underestimations of anthropogenic emissions and natural dust emissions, uncertainties in the spatial and vertical distributions of the anthropogenic emissions, as well as biases in meteorological, radiative, and cloud predictions. Despite moderate to large biases in the chemical predictions, the model performance is generally consistent with or even better than that reported for East Asia with only a few exceptions. The model generally reproduces the observed seasonal variations and the difference between 2006 and 2011 for most variables or chemical species. Overall, these results demonstrate promising skills of WRF-CAM5 for long-term simulations at a regional scale and suggest several areas of potential improvements.

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Section: Observational Datasets and Evaluation Metricsmentioning

confidence: 87%

Application of an Online-Coupled Regional Climate Model, WRF-CAM5, over East Asia for Examination of Ice Nucleation Schemes: Part I. Comprehensive Model Evaluation and Trend Analysis for 2006 and 2011

Chen

Zhang

Fan

et al. 2015

Climate

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“…(2016) showed that modeling the boundary layer winds and PBL development for the Los Angeles basin was greatly improved when using a combination of the Mellor-Yamada-Nakanishi-Niino (MYNN; Nakanishi and Niino, 2004) PBL scheme and the SLUCM. Liao et al (2014) showed that using no urban canopy model and using the BEP UCM both resulted in smaller model errors than SLUCM runs when coupled with the Mellor-Yamada-Janjic (MYJ; Janjić, 1994) PBL scheme in simulations of the Yangtze River Delta. Salamanca et al (2011) also had a study in Houston that produced results that showed that the bulk parameterization scheme for urban surfaces worked well in the prediction of 2-m air temperature.…”

Section: Pbl and Lsm Scheme Sensitivity And Improving Simulations Ovementioning

confidence: 99%

A comprehensive assessment of land surface-atmosphere interactions in a WRF/Urban modeling system for Indianapolis, IN

Sarmiento

Davis

Deng

et al. 2017

Elementa: Science of the Anthropocene

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As part of the Indianapolis Flux (INFLUX) experiment, the accuracy and biases of simulated meteorological fields were assessed for the city of Indianapolis, IN. The INFLUX project allows for a unique opportunity to conduct an extensive observation-to-model comparison in order to assess model errors for the following meteorological variables: latent heat and sensible heat fluxes, air temperature near the surface and in the planetary boundary layer (PBL), wind speed and direction, and PBL height. In order to test the sensitivity of meteorological simulations to different model packages, a set of simulations was performed by implementing different PBL schemes, urban canopy models (UCMs), and a model subroutine that was created in order to reduce an inherent model overestimation of urban land cover. It was found that accurately representing the amount of urban cover in the simulations reduced the biases in most cases during the summertime (SUMMER) simulations. The simulations that used the BEP urban canopy model and the Bougeault & Lacarrere (BouLac) PBL scheme had the smallest biases in the wintertime (WINTER) simulations for most meteorological variables, with the exception being wind direction. The model configuration chosen had a larger impact on model errors during the WINTER simulations, whereas the differences between most of the model configurations during the SUMMER simulations were not statistically significant. By learning the behaviors of different PBL schemes and urban canopy models, researchers can start to understand the expected biases in certain model configurations for their own simulations and have a hypothesis as to the potential errors and biases that might occur when using a multi-physics ensemble based modeling approach.

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“…Additionally, the SLAB scheme that does not consider urban canopy parameters is adopted to model the urban effect. In order to reflect the rapid urban expansion in the YRD region, the default United States Geological Survey (USGS) land-use archives are updated by adding the present urban land-use conditions from 500 m Moderate Resolution Imaging Spectroradiometer (MODIS) data, based on the work of Liao et al (2014Liao et al ( , 2015. The initial meteorological fields and boundary conditions are from 1 • resolution global reanalysis data provided by National Center for Environmental Prediction (NCEP).…”

Section: Model Description and Configurationsmentioning

confidence: 99%

Integrated studies of a regional ozone pollution synthetically affected by subtropical high and typhoon system in the Yangtze River Delta region, China

et al. 2016

Self Cite

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Abstract. Severe high ozone (O 3 ) episodes usually have close relations to synoptic systems. A regional continuous O 3 pollution episode was detected over the Yangtze River Delta (YRD) region in China during 7-12 August 2013, in which the O 3 concentrations in more than half of the cities exceeded the national air quality standard. The maximum hourly concentration of O 3 reached 167.1 ppb. By means of the observational analysis and the numerical simulation, the characteristics and the essential impact factors of the typical regional O 3 pollution are comprehensively investigated. The observational analysis shows that the atmospheric subsidence dominated by the western Pacific subtropical high plays a crucial role in the formation of high-level O 3 . The favorable weather conditions, such as extremely high temperature, low relative humidity and weak wind speed, caused by the abnormally strong subtropical high are responsible for the trapping and the chemical production of O 3 in the boundary layer. In addition, when the YRD cities are at the front of Typhoon Utor, the periphery circulation of typhoon system can enhance the downward airflows and cause worse air quality. However, when the typhoon system weakens the subtropical high, the prevailing southeasterly surface wind leads to the mitigation of the O 3 pollution. The integrated process rate (IPR) analysis incorporated in the Community Multi-scale Air Quality (CMAQ) model is applied to further illustrate the combined influence of subtropical high and typhoon system in this O 3 episode. The results show that the vertical diffusion (VDIF) and the gas-phase chemistry (CHEM) are two major contributors to O 3 formation. During the episode, the contributions of VDIF and CHEM to O 3 maintain the high values over the YRD region. On 10-12 August, the cities close to the sea are apparently affected by the typhoon system, with the contribution of VDIF increasing to 28.45 ppb h −1 in Shanghai and 19.76 ppb h −1 in Hangzhou. In contrast, the cities far away from the sea can hardly be affected by the periphery circulation of typhoon system. When the typhoon system significantly weakens the subtropical high, the contribution values of all individual processes decrease to a low level in all YRD cities. These results provide an insight for the O 3 pollution synthetically impacted by the western Pacific subtropical high and the tropical cyclone system.

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Impacts of different urban canopy schemes in WRF/Chem on regional climate and air quality in Yangtze River Delta, China

Cited by 109 publications

References 41 publications

Application of an Online-Coupled Regional Climate Model, WRF-CAM5, over East Asia for Examination of Ice Nucleation Schemes: Part I. Comprehensive Model Evaluation and Trend Analysis for 2006 and 2011

Application of an Online-Coupled Regional Climate Model, WRF-CAM5, over East Asia for Examination of Ice Nucleation Schemes: Part I. Comprehensive Model Evaluation and Trend Analysis for 2006 and 2011

A comprehensive assessment of land surface-atmosphere interactions in a WRF/Urban modeling system for Indianapolis, IN

Integrated studies of a regional ozone pollution synthetically affected by subtropical high and typhoon system in the Yangtze River Delta region, China

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