scholarly journals Development of WRF/CUACE v1.0 model and its preliminary application in simulating air quality in China

2020 ◽  
Author(s):  
Lei Zhang ◽  
Sunling Gong ◽  
Tianliang Zhao ◽  
Chunhong Zhou ◽  
Yuesi Wang ◽  
...  
Keyword(s):  
Air Quality ◽  
Chemical Reactions ◽  
Atmospheric Chemistry ◽  
Eastern China ◽  
Weather Research And Forecasting ◽  
Deep Basin ◽  
China Meteorological Administration ◽  
The North ◽  
Haze Pollution ◽  
Pollution Event

Abstract. The development of chemical transport models with advanced physics and chemical schemes could improve air-quality forecasts. In this study, the China Meteorological Administration Unified Atmospheric Chemistry Environment (CUACE) model, a comprehensive chemistry module incorporating gaseous chemistry and a size-segregated multicomponent aerosol algorithm, was coupled to the Weather Research and Forecasting (WRF)-Chem framework using an interface procedure to build the WRF/CUACE v1.0 model. The latest version of CUACE includes an updated aerosol dry deposition scheme and the introduction of heterogeneous chemical reactions on aerosol surfaces. We evaluated the WRF/CUACE v1.0 model by simulating PM2.5, O3, and NO2 concentrations for January, April, July, and October (representing winter, spring, summer, and autumn, respectively) in 2013, 2015, and 2017 and comparing them with ground-based observations. Secondary inorganic aerosol simulations were also evaluated through a simulation of a heavy haze pollution event during 9–15 January 2019 in the North China Plain. The model well captured the variations of PM2.5, O3, and NO2 concentrations in all seasons in eastern China. However, it is difficult to accurately reproduce the variations of air pollutants over Sichuan Basin, due to its deep basin terrain. The sulfate and nitrate simulations are substantially improved by introducing heterogenous chemical reactions into the CUACE model (change in bias from −95.0 % to 4.1 % for sulfate and from 124.1 % to 96.0 % for nitrate). The development of the WRF/CUACE v1.0 model represents an important step towards improving air-quality modelling and forecasts in China.

scholarly journals Development of WRF/CUACE v1.0 model and its preliminary application in simulating air quality in China

2021 ◽  
Vol 14 (2) ◽  
pp. 703-718 ◽  
Author(s):  
Lei Zhang ◽  
Sunling Gong ◽  
Tianliang Zhao ◽  
Chunhong Zhou ◽  
Yuesi Wang ◽  
...  
Keyword(s):  
Air Quality ◽  
Chemical Reactions ◽  
Atmospheric Chemistry ◽  
Mesoscale Model ◽  
Eastern China ◽  
River Delta ◽  
Deep Basin ◽  
China Meteorological Administration ◽  
Heterogeneous Chemical ◽  
Heterogeneous Chemical Reactions

Abstract. The development of chemical transport models with advanced physics and chemical schemes could improve air-quality forecasts. In this study, the China Meteorological Administration Unified Atmospheric Chemistry Environment (CUACE) model, a comprehensive chemistry module incorporating gaseous chemistry and a size-segregated multicomponent aerosol algorithm, was coupled to the Weather Research and Forecasting (WRF) framework with chemistry (WRF-Chem) using an interface procedure to build the WRF/CUACE v1.0 model. The latest version of CUACE includes an updated aerosol dry deposition scheme and the introduction of heterogeneous chemical reactions on aerosol surfaces. We evaluated the WRF/CUACE v1.0 model by simulating PM2.5, O3, NO2, and SO2 concentrations for January, April, July, and October (representing winter, spring, summer and autumn, respectively) in 2013, 2015, and 2017 and comparing them with ground-based observations. Secondary inorganic aerosol simulations for the North China Plain (NCP), Yangtze River Delta (YRD), and Sichuan Basin (SCB) were also evaluated. The model captured well the variations of PM2.5, O3, and NO2 concentrations in all seasons in eastern China. However, it is difficult to accurately reproduce the variations of air pollutants over SCB, due to its deep basin terrain. The simulations of SO2 were generally reasonable in the NCP and YRD with the bias at −15.5 % and 24.55 %, respectively, while they were poor in the Pearl River Delta (PRD) and SCB. The sulfate and nitrate simulations were substantially improved by introducing heterogeneous chemical reactions into the CUACE model (e.g., change in bias from −95.0 % to 4.1 % for sulfate and from 124.1 % to 96.0 % for nitrate in the NCP). Additionally, The WRF/CUACE v1.0 model was revealed with better performance in simulating chemical species relative to the coupled Fifth-Generation Penn State/NCAR Mesoscale Model (MM5) and CUACE model. The development of the WRF/CUACE v1.0 model represents an important step towards improving air-quality modeling and forecasts in China.

scholarly journals Significant increase of summertime ozone at Mount Tai in Central Eastern China

2016 ◽  
Vol 16 (16) ◽  
pp. 10637-10650 ◽  
Author(s):  
Lei Sun ◽  
Likun Xue ◽  
Tao Wang ◽  
Jian Gao ◽  
Aijun Ding ◽  
...  
Keyword(s):  
Atmospheric Chemistry ◽  
Production Efficiency ◽  
North China ◽  
Climate Model ◽  
Eastern China ◽  
Linear Regression Analysis ◽  
Ozone Production ◽  
The North ◽  
Short Period ◽  
Central Eastern

Abstract. Tropospheric ozone (O3) is a trace gas playing important roles in atmospheric chemistry, air quality and climate change. In contrast to North America and Europe, long-term measurements of surface O3 are very limited in China. We compile available O3 observations at Mt. Tai – the highest mountain over the North China Plain – during 2003–2015 and analyze the decadal change of O3 and its sources. A linear regression analysis shows that summertime O3 measured at Mt. Tai has increased significantly by 1.7 ppbv yr−1 for June and 2.1 ppbv yr−1 for the July–August average. The observed increase is supported by a global chemistry-climate model hindcast (GFDL-AM3) with O3 precursor emissions varying from year to year over 1980–2014. Analysis of satellite data indicates that the O3 increase was mainly due to the increased emissions of O3 precursors, in particular volatile organic compounds (VOCs). An important finding is that the emissions of nitrogen oxides (NOx) have diminished since 2011, but the increase of VOCs appears to have enhanced the ozone production efficiency and contributed to the observed O3 increase in central eastern China. We present evidence that controlling NOx alone, in the absence of VOC controls, is not sufficient to reduce regional O3 levels in North China in a short period.

Substantial degradation in Air Quality due to Saddleworth Moor Wildfire

2020 ◽  
Author(s):  
Ailish Graham ◽  
James McQuaid ◽  
Stephen Arnold ◽  
Kirsty Pringle ◽  
Richard Pope ◽  
...  
Keyword(s):  
Air Quality ◽  
Atmospheric Chemistry ◽  
Excess Mortality ◽  
Health Impact ◽  
Short Term ◽  
North West ◽  
The North ◽  
Short Term Exposure ◽  
The Uk ◽  
The Impact

<p>On June 24<sup>th</sup> 2018 one of the largest UK wildfires in recent history broke out on Saddleworth Moor, close to Manchester, in north-west England. June 2018 was anomalously hot and dry across the UK which led to the peat on the moor drying out and becoming suscpetible to ignition. Since wildfires close to large populations in the UK have been relatively small and rare in the past, there is little knowledge about the impacts. This has prevented the development of effective strategies to reduce them. This paper uses a high-resolution coupled atmospheric-chemistry model to assess the impact of the fires on particulate matter with a diameter less than 2.5 µm (PM<sub>2.5</sub>) air quality (AQ) across the north-west region and the subsequent impact on health from short-term exposure. We find that the fires substantially degraded AQ across the north-west. PM<sub>2.5 </sub>concentrations increased by more than 300% in Oldham and Manchester and up to 50% in areas up to 80 km away such as Liverpool, Wigan and Warrington. This led to a third of the population (4.7 million people) in the simulation domain (-4.9-0.7°E and 53.0-54.4°N) being exposed to moderate PM<sub>2.5 </sub>concentrations on at least one day, according to the Daily Air Quality Index (36-53 µg m<sup>-3</sup>), between June 23<sup>rd</sup> and 30<sup>th </sup>2018. This equates to 4.5 million people being exposed to PM<sub>2.5 </sub>above the WHO 24-hour safe-limit exposure of 25 µg m<sup>-3</sup> on at least one day. Using a concentration-response function we calculate the short-term health impact which indicates that up to 60% of excess mortality between June 23<sup>rd</sup> and 30<sup>th</sup> 2018 was attributable to the fires. This represents up to a 165% increase in excess mortality across the region compared to a simulation with no fires. We find the impact of mortality due to PM<sub>2.5 </sub>from the fires on the economy was also substantial (£5.5m). Thus, our results indicate the need to introduce legislation and education to both reduce the likelihood of wildfires and reduce the population’s exposure to harmful air pollutants during their occurrence. This is particularly relevant given that wildfires are projected to become more common in the future through climate change and land-use change.</p>

scholarly journals Impacts of shipping emissions on PM<sub>2.5</sub> pollution in China

2018 ◽  
Vol 18 (21) ◽  
pp. 15811-15824 ◽  
Author(s):  
Zhaofeng Lv ◽  
Huan Liu ◽  
Qi Ying ◽  
Mingliang Fu ◽  
Zhihang Meng ◽  
...  
Keyword(s):  
Air Quality ◽  
Seasonal Variations ◽  
Yangtze River ◽  
Eastern China ◽  
Yangtze River Delta ◽  
Control Area ◽  
River Delta ◽  
The North ◽  
Fast Development ◽  
The Yrd

Abstract. With the fast development of seaborne trade and relatively more efforts on reducing emissions from other sources in China, shipping emissions contribute more and more significantly to air pollution. In this study, based on a shipping emission inventory with high spatial and temporal resolution within 200 nautical miles (Nm) to the Chinese coastline, the Community Multiscale Air Quality (CMAQ) model was applied to quantify the impacts of the shipping sector on the annual and seasonal concentrations of PM2.5 for the base year 2015 in China. Emissions within 12 Nm accounted for 51.2 %–56.5 % of the total shipping emissions, and the distinct seasonal variations in spatial distribution were observed. The modeling results showed that shipping emissions increased the annual averaged PM2.5 concentrations in eastern China up to 5.2 µg m−3, and the impacts in YRD (Yangtze River Delta) and PRD (Pearl River Delta) were much greater than those in BTH (Beijing–Tianjin–Hebei). Shipping emissions influenced the air quality in not only coastal areas but also the inland areas hundreds of kilometers (up to 960 km) away from the sea. The impacts on the PM2.5 showed obvious seasonal variations, and patterns in the north and south of the Yangtze River were also quite different. In addition, since the onshore wind can carry ship pollutants to inland areas, the daily contributions of shipping emissions in onshore flow days were about 1.8–2.7 times higher than those in the rest of the days. A source-oriented CMAQ was used to estimate the contributions of shipping emissions from maritime areas within 0–12, 12–50, 50–100 and 100–200 Nm to PM2.5 concentrations. The results indicated that shipping emissions within 12 Nm were the dominant contributor, with contributions 30 %–90 % of the total impacts induced by emissions within 200 Nm, while a relatively high contribution (40 %–60 %) of shipping emissions within 20–100 Nm was observed in the north of the YRD region and south of Lianyungang, due to the major water traffic lanes far from land. The results presented in this work implied that shipping emissions had significant influence on air quality in China, and to reduce its pollution, the current Domestic Emission Control Area (DECA) should be expanded to at least 100 Nm from the coastline.

scholarly journals Air Quality and Climate Change, Topic 3 of the Model Inter-Comparison Study for Asia Phase III (MICS-Asia III), Part II: aerosol radiative effects and aerosol feedbacks

2019 ◽  
Author(s):  
Meng Gao ◽  
Zhiwei Han ◽  
Zhining Tao ◽  
Jiawei Li ◽  
Jeong-Eon Kang ◽  
...  
Keyword(s):  
Air Quality ◽  
Radiative Forcing ◽  
Eastern China ◽  
Phase Iii ◽  
Comparison Study ◽  
Near Surface ◽  
Aerosol Radiative Forcing ◽  
The North ◽  
Bth Region ◽  
Aerosol Radiative

Abstract. Topic 3 of the Model Inter-Comparison Study for Asia (MICS-Asia) Phase III examines how online coupled air quality models perform in simulating high aerosol pollution in the North China Plain region during wintertime haze events and evaluates the importance of aerosol radiative and microphysical feedbacks. This paper discusses the estimates of aerosol radiative forcing, aerosol feedbacks, and possible causes for the differences among the models. Over the Beijing-Tianjin-Hebei (BTH) region, the ensemble mean of aerosol direct radiative forcing (ADRF) at the top of atmosphere, inside the atmosphere and at the surface are −1.9, 8.4 and −10.3 W/m2, respectively. Subdivisions of direct and indirect aerosol radiative forcing confirm the dominant roles of direct forcing. During severe haze days (January 17–19, 2010), the averaged reduction in near surface temperature for the BTH region can reach 0.3–3.0 ºC. The responses of wind speeds at 10 m (WS10) inferred from different models show consistent declines in eastern China. For the BTH region, aerosol-radiation feedback induced changes in PM2.5 range from 6.0 to 8.8 µg/m3 (

scholarly journals Impacts of shipping emissions on PM<sub>2.5</sub> air pollution in China

2018 ◽  
Author(s):  
Zhaofeng Lv ◽  
Huan Liu ◽  
Qi Ying ◽  
Mingliang Fu ◽  
Zhihang Meng ◽  
...  
Keyword(s):  
Air Pollution ◽  
Air Quality ◽  
Yangtze River ◽  
Eastern China ◽  
Yangtze River Delta ◽  
River Delta ◽  
Onshore Wind ◽  
The North ◽  
Fast Development ◽  
North And South

Abstract. With the fast development of seaborne trade and relatively more efforts on reducing emissions from other sources in China, shipping emissions contribute more and more significantly to air pollution. In this study, based on a shipping emission inventory with high spatial and temporal resolution within 200 nautical miles (Nm) to the Chinese coastline, the Community Multiscale Air Quality (CMAQ) model was applied to quantify the impacts of the shipping sector on the annual and seasonal concentrations of PM2.5 for the base year 2015 in China. Emissions within 12 Nm accounted for 51.2 %–56.5 % of the total shipping emissions, and the distinct seasonal variations in spatial distribution were observed. The modeling results showed that shipping emissions increased the annual averaged PM2.5 concentrations in eastern China up to 5.2 μg/m3, and the impacts in YRD (Yangtze River Delta) and PRD (Pearl River Delta) were much greater than those in BTH (Beijing-Tianjin-Hebei). Shipping emissions influenced the air quality in not only coastal areas but also the inland areas hundreds of kilometers (up to 960 km) away from the sea. The impacts on the PM2.5 showed obvious seasonal variability, and patterns in the north and south of the Yangtze river were also quite different. In addition, since the onshore wind can carry ship pollutants to inland areas, the daily contributions of shipping emissions in onshore flow days were about 1.8–2.7 times higher than that in rest of days. A source-oriented CMAQ was used to estimate the contributions of shipping emissions from maritime areas within 0–12 Nm, 12–50 Nm, 50–100 Nm and 100–200 Nm to PM2.5 concentrations. The results indicated that shipping emissions within 12 Nm were the dominant contributor with contributions 30–90 % of the total impacts induced by emissions with 200 Nm. While a relative high contribution (40–60 %) of shipping emissions within 20–100 Nm was observed in the north of PRD region and south of Lianyungang, due to the major water traffic lanes far from land.

scholarly journals INVESTIGATING ALOFT AEROSOLS OVER CENTRAL-EASTERN CHINA USING CALIPSO MEASUREMENTS

2018 ◽  
Vol XLII-3/W5 ◽  
pp. 83-88
Author(s):  
J. Zou ◽  
K. Qin ◽  
J. Xu ◽  
X. Han
Keyword(s):  
North China ◽  
Rapid Development ◽  
Eastern China ◽  
Yangtze River Delta ◽  
Anthropogenic Source ◽  
Anthropogenic Aerosols ◽  
The North ◽  
Haze Pollution ◽  
Central Eastern ◽  
The Yrd

<p><strong>Abstract.</strong> The rapid development of China in the last decade has brought about serious environmental problems, among which the air quality has attracted much attention. Especially in the winter, haze events with PM<sub>2.5</sub> as the primary pollutant frequently occur, which has a huge strike on people's health. Such cumulative anthropogenic aerosols at surface over haze pollution regions could be lifted upwards by vertical turbulent mixing forming elevated haze layers that subsequent transport to distant regions. This paper attempts to analyze layer top altitude, ratio of anthropogenic source and optical properties by counting events occurring in aloft aerosols layer. CALIPSO satellite instruments are used for statistical analysis by screening layer data over central-eastern China from 2007 to 2016. In the most economically active and polluted areas of China, the North China Plain (NCP) and the Yangtze River Delta (YRD) are compared to analyze trend variations over ten years. Results shows that the frequency of occurrence of aloft layer in South China are higher than in North China, indicating that heat has a strong lifting effect on the planetary boundary layer (PBL). Further, the NCP has a unique high frequency value at 2.5<span class="thinspace"></span>km, while the YRD has two peaks, 3.5<span class="thinspace"></span>km and 2 km respectively. Moreover, in the past five years in the NCP (2011&amp;ndash;2016) and YRD (2012&amp;ndash;2016) regions, the anthropogenic source of pollutants dominated by smoke showed a downward trend year by year. In addition, monthly proportion of smoke and polluted dust are analyzed in NCP and YRD winter. Finally, the volume depolarization ratio is almost distributed within 0.2, indicating that the shape of the particles is irregular. The particulate color ratio has a sharp peak near 0.4&amp;ndash;0.7 suggesting that smaller particles dominate the size distribution during the winter months.</p>

scholarly journals Aerosol transport pathways and source attribution in China during the COVID-19 outbreak

2021 ◽  
Vol 21 (20) ◽  
pp. 15431-15445
Author(s):  
Lili Ren ◽  
Yang Yang ◽  
Hailong Wang ◽  
Pinya Wang ◽  
Lei Chen ◽  
...  
Keyword(s):  
Air Quality ◽  
North China Plain ◽  
North China ◽  
Eastern China ◽  
Lower Troposphere ◽  
Aerosol Transport ◽  
Transport Pathways ◽  
The North ◽  
The North China Plain ◽  
Local Emissions

Abstract. Due to the coronavirus disease 2019 (COVID-19) pandemic, human activities and industrial productions were strictly restricted during January–March 2020 in China. Despite the fact that anthropogenic aerosol emissions largely decreased, haze events still occurred. Characterization of aerosol transport pathways and attribution of aerosol sources from specific regions are beneficial to air quality and pandemic control strategies. This study establishes source–receptor relationships in various regions covering all of China during the COVID-19 outbreak based on the Community Atmosphere Model version 5 with Explicit Aerosol Source Tagging (CAM5-EAST). Our analysis shows that PM2.5 burden over the North China Plain between 30 January and 19 February is mostly contributed by local emissions (40 %–66 %). For other regions in China, PM2.5 burden is largely contributed from nonlocal sources. During the most polluted days of the COVID-19 outbreak, local emissions within the North China Plain and eastern China contributed 66 % and 87 % to the increase in surface PM2.5 concentrations, respectively. This is associated with the anomalous mid-tropospheric high pressure at the location of the climatological East Asia trough and the consequently weakened winds in the lower troposphere, leading to the local aerosol accumulation. The emissions outside China, especially those from South Asia and Southeast Asia, contribute over 50 % to the increase in PM2.5 concentration in southwestern China through transboundary transport during the most polluted day. As the reduction in emissions in the near future is desirable, aerosols from long-range transport and unfavorable meteorological conditions are increasingly important to regional air quality and need to be taken into account in clean-air plans.

Assessment of Emission Reduction Scenarios with a Focus on the Impact of Vehicle Fleets on Tehran Air Quality: Case Study

2019 ◽  
Vol 2673 (5) ◽  
pp. 197-207 ◽  
Author(s):  
Hossein Shahbazi ◽  
Vahid Hosseini ◽  
Sara Torbatian ◽  
Masoud Hamedi
Keyword(s):  
Air Quality ◽  
Weather Research And Forecasting ◽  
Air Quality Model ◽  
Quality Model ◽  
Passenger Cars ◽  
Pollutant Concentrations ◽  
Modeling Systems ◽  
Vehicle Category ◽  
Pollution Event ◽  
The Impact

In recent years, the city of Tehran has frequently experienced severe air pollution episodes, and the increase in the use of vehicles has exacerbated this critical situation. It is unclear to what extent each vehicle category contributes to the production of pollution during a pollution event. For this purpose, a combination of the weather research and forecasting (WRF) and the Comprehensive Air Quality Model with Extensions (CAMx) modeling systems was used to simulate the distributions of pollutant concentrations over Tehran in a pollution episode from December 3 to 23, 2017. First, the performance of the modeling system was evaluated with respect to the simulation outputs against observations. Results showed satisfactory performance by the models in predicting meteorological parameters and pollutant concentrations. There were some discrepancies between measured and simulated pollutant levels that might have several causes, including, for example, not considering dust emissions in the system. The second step focused on the assessment of different emission scenarios to quantify the impact of each vehicle fleet in producing pollution during such severe episodes. For this reason, eight different scenarios were considered in which the emissions of each vehicle category were entirely eliminated from the corresponding scenario. The results show that the removal of passenger cars and motorcycles could have the most significant impact on PM2.5 reduction, with a maximum drop of 32% and 30%, respectively. In addition, the NO2 concentrations could be reduced by about 20% and 10% as a result of the removal of passenger cars and motorcycles, respectively. Finally, two traffic schemes with a main focus on the role of motorcycles on the degradation of Tehran’s air quality were also examined for the same episode.

scholarly journals Detection of critical PM<sub>2.5</sub> emission sources and their contributions to a heavy haze episode in Beijing, China, using an adjoint model

2018 ◽  
Vol 18 (9) ◽  
pp. 6241-6258 ◽  
Author(s):  
Shixian Zhai ◽  
Xingqin An ◽  
Tianliang Zhao ◽  
Zhaobin Sun ◽  
Wei Wang ◽  
...  
Keyword(s):  
Air Quality ◽  
Atmospheric Chemistry ◽  
Hebei Province ◽  
Emission Sources ◽  
Adjoint Model ◽  
Concentration Peak ◽  
Haze Pollution ◽  
Haze Episode ◽  
Primary Emissions ◽  
Pm2.5 Concentration

Abstract. Air pollution sources and their regional transport are important issues for air quality control. The Global–Regional Assimilation and Prediction System coupled with the China Meteorological Administration Unified Atmospheric Chemistry Environment (GRAPES–CUACE) aerosol adjoint model was applied to detect the sensitive primary emission sources of a haze episode in Beijing occurring between 19 and 21 November 2012. The high PM2.5 concentration peaks occurring at 05:00 and 23:00 LT (GMT+8) over Beijing on 21 November 2012 were set as the cost functions for the aerosol adjoint model. The critical emission regions of the first PM2.5 concentration peak were tracked to the west and south of Beijing, with 2 to 3 days of cumulative transport of air pollutants to Beijing. The critical emission regions of the second peak were mainly located to the south of Beijing, where southeasterly moist air transport led to the hygroscopic growth of particles and pollutant convergence in front of the Taihang Mountains during the daytime on 21 November. The temporal variations in the sensitivity coefficients for the two PM2.5 concentration peaks revealed that the response time of the onset of Beijing haze pollution from the local primary emissions is approximately 1–2 h and that from the surrounding primary emissions it is approximately 7–12 h. The upstream Hebei province has the largest impact on the two PM2.5 concentration peaks, and the contribution of emissions from Hebei province to the first PM2.5 concentration peak (43.6 %) is greater than that to the second PM2.5 concentration peak (41.5 %). The second most influential province for the 05:00 LT PM2.5 concentration peak is Beijing (31.2 %), followed by Shanxi (9.8 %), Tianjin (9.8 %), and Shandong (5.7 %). The second most influential province for the 23:00 LT PM2.5 concentration peak is Beijing (35.7 %), followed by Shanxi (8.1 %), Shandong (8.0 %), and Tianjin (6.7 %). The adjoint model results were compared with the forward sensitivity simulations of the Models-3/CMAQ system. The two modeling approaches are highly comparable in their assessments of atmospheric pollution control schemes for critical emission regions, but the adjoint method has higher computational efficiency than the forward sensitivity method. The results also imply that critical regional emission reduction could be more efficient than individual peak emission control for improving regional PM2.5 air quality.

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