scholarly journals Impacts of Meteorological Conditions, Aerosol Radiative Feedbacks, and Emission Reduction Scenarios on the Coastal Haze Episodes in Southeastern China in December 2013

2017 ◽  
Vol 56 (5) ◽  
pp. 1209-1229 ◽  
Author(s):  
Jianqiong Zhan ◽  
Wenyuan Chang ◽  
Wei Li ◽  
Yanming Wang ◽  
Liqi Chen ◽  
...  
Keyword(s):  
Air Quality ◽  
Regional Cooperation ◽  
Coastal Region ◽  
Northern China ◽  
Yangtze River Delta ◽  
Meteorological Conditions ◽  
Fujian Province ◽  
The North ◽  
Radiative Feedbacks ◽  
Aerosol Radiative

AbstractFujian Province in southeastern coastal China is a relatively clean region with low emissions, as its high altitude isolates it from the rest of the country. However, the region experienced haze episodes on 3–14 December 2013. The authors performed simulations using the Weather Research and Forecasting Model coupled with chemistry (WRF-Chem) to examine the impacts of meteorological conditions, aerosol radiative feedbacks (ARFs; including aerosol direct and nearly first indirect effect), and internal and external emissions reduction scenarios on particulate matter smaller than 2.5 μm (PM2.5) concentrations. To the best of the authors’ knowledge, this is the first time the WRF-Chem model has been used to study air quality in this region. The model reasonably reproduced the meteorological conditions and PM2.5 concentrations. The analysis demonstrated that the highest-PM2.5 event was associated with a cold surge that promoted the impingement of northern pollutants on the region, and PM2.5 concentrations were sensitive to the emissions from the Yangtze River delta (16.6%) and the North China Plain (12.1%). This suggests that efforts toward coastal air quality improvement require regional cooperation to reduce emissions. Noticeably, ARFs were unlikely to increase PM2.5 concentrations in the coastal region, which was in contrast to the case in northern China. ARFs induced strong clean wind anomalies in the coastal region and also lowered the inland planetary boundary layer, which enhanced the blocking of northern pollutants crossing the high terrain in the north of Fujian Province. This indicates that ARFs tend to weaken the haze intensity in the southeastern coastal region.

scholarly journals Characteristics of Air Pollution and Their Relationship with Meteorological Parameters: Northern Versus Southern Cities of China

Atmosphere ◽  
2020 ◽  
Vol 11 (3) ◽  
pp. 253
Author(s):  
Haitao Zhou ◽  
Yueming Yu ◽  
Xuan Gu ◽  
Yun Wu ◽  
Mei Wang ◽  
...  
Keyword(s):  
Air Pollution ◽  
Air Quality ◽  
Meteorological Conditions ◽  
Control Measures ◽  
Current Standard ◽  
The North ◽  
Pollutant Concentrations ◽  
Abnormal Phenomenon ◽  
Southern City ◽  
Northern City

Air pollution shows a generally decreasing trend from the north to the south in China since 2013 (GB3095-2012, the current standard for monitoring). However, an opposite observation was recorded in 2017, especially in winter. In this study, we collected monitoring data of six air pollutants in 2016 and 2017, from a northern city (Beijing) and a southern city (Nanjing) for comparison. As air pollution was highly dependent upon meteorological conditions, we further analyzed their relationships to explain this abnormal phenomenon. Seasonal averaged PM2.5, PM10, SO2, CO, and NO2 were negatively correlated with wind scale (WS) while 8-h O3 exhibited an opposite relationship. Relative humidity (RH) has opposite effects on the concentrations of different pollutants in Beijing and Nanjing. The 8-h O3 showed the closest positive correlation with temperature (T), which is due to its formation mechanism. In Beijing, decreased RH, together with more wind from northwest in winter, resulted in an improved air quality in 2017. In Nanjing, WS, RH, T, and wind direction fluctuated within a narrow range in each season, leading to relatively stable pollutant concentrations. These results suggest that meteorological conditions are important factors to evaluate the air quality and implement control measures.

scholarly journals PLAM – a meteorological pollution index for air quality and its applications in fog-haze forecasts in North China

2016 ◽  
Vol 16 (3) ◽  
pp. 1353-1364 ◽  
Author(s):  
Y. Q. Yang ◽  
J. Z. Wang ◽  
S. L. Gong ◽  
X. Y. Zhang ◽  
H. Wang ◽  
...  
Keyword(s):  
Air Quality ◽  
Large Scale ◽  
North China ◽  
Pollution Index ◽  
Meteorological Conditions ◽  
Bohai Bay ◽  
Emission Data ◽  
H Index ◽  
The North ◽  
Significance Levels

Abstract. Using surface meteorological observation and high-resolution emission data, this paper discusses the application of the PLAM/h index (Parameter Linking Air-quality to Meteorological conditions/haze) in the prediction of large-scale low visibility and fog-haze events. Based on the two-dimensional probability density function diagnosis model for emissions, the study extends the diagnosis and prediction of the meteorological pollution index PLAM to the regional visibility fog-haze intensity. The results show that combining the influence of regular meteorological conditions and emission factors together in the PLAM/h parameterization scheme is very effective in improving the diagnostic identification ability of the fog-haze weather in North China. The determination coefficients for four seasons (spring, summer, autumn, and winter) between PLAM/h and visibility observation are 0.76, 0.80, 0.96, and 0.86, respectively, and all of their significance levels exceed 0.001, showing the ability of PLAM/h to predict the seasonal changes and differences of fog-haze weather in the North China region. The high-value correlation zones are located in Jing-Jin-Ji (Beijing, Tianjin, Hebei), Bohai Bay rim, and southern Hebei–northern Henan, indicating that the PLAM/h index is related to the distribution of frequent heavy fog-haze weather in North China and the distribution of emission high-value zone. Through comparative analysis of the heavy fog-haze events and large-scale clear-weather processes in winter and summer, it is found that PLAM/h index 24 h forecast is highly correlated with the visibility observation. Therefore, the PLAM/h index has good capability in identification, analysis, and forecasting.

scholarly journals PLAM – a meteorological pollution index for air quality and its applications in fog-haze forecasts in north China

2015 ◽  
Vol 15 (6) ◽  
pp. 9077-9106 ◽  
Author(s):  
Y. Yang ◽  
J. Wang ◽  
S. Gong ◽  
X. Zhang ◽  
H. Wang ◽  
...  
Keyword(s):  
Air Quality ◽  
Large Scale ◽  
North China ◽  
Correlation Coefficients ◽  
Pollution Index ◽  
Meteorological Conditions ◽  
Bohai Bay ◽  
Emission Data ◽  
H Index ◽  
The North

Abstract. Using surface meteorological observation and high resolution emission data, this paper discusses the application of PLAM/h Index (Parameter Linking Air-quality to Meteorological conditions/haze) in the prediction of large-scale low visibility and fog-haze events. Based on the two-dimensional probability density function diagnosis model for emissions, the study extends the diagnosis and prediction of the meteorological pollution index PLAM to the regional visibility fog-haze intensity. The results show that combining the influence of regular meteorological conditions and emission factors together in the PLAM/h parameterization scheme is very effective in improving the diagnostic identification ability of the fog-haze weather in North China. The correlation coefficients for four seasons (spring, summer, autumn and winter) between PLAM/h and visibility observation are 0.76, 0.80, 0.96 and 0.86 respectively and all their significance levels exceed 0.001, showing the ability of PLAM/h to predict the seasonal changes and differences of fog-haze weather in the North China region. The high-value correlation zones are respectively located in Jing-Jin-Ji (Beijing, Tianjin, Hebei), Bohai Bay rim and the southern Hebei-northern Henan, indicating that the PLAM/h index has relations with the distribution of frequent heavy fog-haze weather in North China and the distribution of emission high-value zone. Comparatively analyzing the heavy fog-haze events and large-scale fine weather processes in winter and summer, it is found that PLAM/h index 24 h forecast is highly correlated to the visibility observation. Therefore, PLAM/h index has better capability of doing identification, analysis and forecasting.

scholarly journals Impact of Meteorological Conditions on PM2.5 Pollution in China during Winter

Atmosphere ◽  
2018 ◽  
Vol 9 (11) ◽  
pp. 429 ◽  
Author(s):  
Yanling Xu ◽  
Wenbo Xue ◽  
Yu Lei ◽  
Yang Zhao ◽  
Shuiyuan Cheng ◽  
...  
Keyword(s):  
Air Quality ◽  
Fine Particulate Matter ◽  
Yangtze River Delta ◽  
Meteorological Conditions ◽  
River Delta ◽  
Boundary Layer Height ◽  
Low Wind Speed ◽  
The Pearl River ◽  
The Relationship ◽  
Pm2.5 Concentration

Fine particulate matter (PM2.5) poses a risk to human health. In January 2017, the PM2.5 pollution in China was severe, and the average PM2.5 concentration had increased by 14.7% compared to that in January 2016. Meteorological conditions greatly influence PM2.5 pollution. The relationship between PM2.5 and meteorological factors was assessed using monitoring data and the Community Multiscale Air Quality modeling system (CMAQ) was used to quantitatively evaluate the impacts of variations of meteorological conditions on PM2.5 pollution. The results indicate that variations of meteorological conditions between January 2017 and January 2016 caused an increase of 13.6% in the national mean concentration of PM2.5. Unlike the Yangtze River Delta (YRD), where meteorological conditions were favorable, unfavorable meteorological conditions (such as low wind speed, high humidity, low boundary layer height and low rainfall) contributed to PM2.5 concentration worsening by 29.7%, 42.6% and 7.9% in the Beijing-Tianjin-Hebei (JJJ) region, the Pearl River Delta (PRD) region and the Chengdu-Chongqing (CYB) region, respectively. Given the significant influence of local meteorology on PM2.5 concentration, more emphasis should be placed on employing meteorological means to improve local air quality.

scholarly journals The impact of multi-species surface chemical observations assimilation on the air quality forecasts in China

2018 ◽  
Author(s):  
Zhen Peng ◽  
Lili Lei ◽  
Zhiquan Liu ◽  
Jianning Sun ◽  
Aijun Ding ◽  
...  
Keyword(s):  
Air Quality ◽  
Transport Model ◽  
Initial Conditions ◽  
Yangtze River Delta ◽  
River Delta ◽  
Chemical Transport Model ◽  
The North ◽  
Surface Measurements ◽  
Haze Episode ◽  
The Impact

Abstract. An Ensemble Kalman Filter data assimilation (DA) system has been developed to improve air quality forecasts using surface measurements of PM10, PM2.5, SO2, NO2, O3 and CO together with an online regional chemical transport model, WRF-Chem (Weather Research and Forecasting with Chemistry). This DA system was applied to simultaneously adjust the chemical initial conditions (ICs) and emission inputs of the species affecting PM10, PM2.5, SO2, NO2, O3 and CO concentrations during an extreme haze episode that occurred in early October 2014 over the North China Plain. Numerical experimental results indicate that ICs play key roles in PM2.5, PM10 and CO forecasts during the severe haze episode. The 72-h verification forecasts with the optimized ICs and emissions performed very similarly to the verification forecasts with only optimized ICs and the prescribed emissions. For the first-day forecast, near perfect verification forecasts results were achieved. However, with longer range forecasts, the DA impacts decayed quickly. For the SO2 verification forecasts, it was efficient to improve the SO2 forecast via the joint adjustment of SO2 ICs and emissions. Large improvements were achieved for SO2 forecasts with both the optimized ICs and emissions for the whole 72-h forecast range. Similar improvements were achieved for SO2 forecasts with optimized ICs only for just the first 3 h, and then the impact of the ICs decayed quickly. For the NO2 verification forecasts, both forecasts performed much worse than the control run without DA. Plus, the 72-h O3 verification forecasts performed worse than the control run during the daytime, due to the worse performance of the NO2 forecasts, even though they performed better at night. However, relatively favorable NO2 and O3 forecast results were achieved for the Yangtze River delta and Pearl River delta regions.

scholarly journals Study on long-term aerosol distribution over the land of East China using MODIS data

2011 ◽  
Vol 11 (4) ◽  
pp. 10485-10523 ◽  
Author(s):  
Q. He ◽  
C. Li ◽  
F. Geng ◽  
Y. Lei ◽  
Y. Li ◽  
...  
Keyword(s):  
Regional Climate ◽  
Yangtze River Delta ◽  
Meteorological Conditions ◽  
Dust Particles ◽  
East China ◽  
Dust Transport ◽  
Aerosol Loading ◽  
The North ◽  
Dry Zone ◽  
Fine Mode

Abstract. East China is among the fastest developing and most populous area in Asia, where atmospheric aerosol loading is high due to heavy urban and industrial emission. These aerosols may have significant impact on regional climate and environment. In this report, MODIS level 2 aerosol products (2000–2007) were used to study aerosol spatial and temporal distributions, as well as their variations with local meteorological conditions over East China. By combining Aerosol Optical Depth (AOD) and aerosol Fine Mode Fraction (FMF), we found that the urban/industrial aerosol and dust are two dominant species over northern part, whereas continental, marine and mixed aerosols dominate the southern part of East China, except for Poyang Lake Plain. Both annual mean AOD and area with high AOD increased from 2000 to 2007, with the largest increase seen in Yangtze River Delta region (YRD). In summer, AOD in East China reached the maximum of about 0.8 in YRD, dominated by fine mode particles. The minimum AOD occurred in winter with mostly coarse mode particles. The higher AOD in spring is attributed to coarse particles. Local aerosol properties were analyzed in three typical zones: the northern dry zone (I), the central urban/industrial zone (II) and the southern natural background zone (III). Monthly mean AODs in zone I and II were above 0.5 throughout the entire year, with the maximum AOD in June. High FMFs in this period indicated heavy urban and industrial pollutions. Monthly mean AODs and FMFs in zone III reached maximum of 0.51 in April and September (up to 90.7%) respectively. High AOD in spring in zone III appears mostly due to the long-range dust transport from the North. In fact, dust particles contributed 50–80% to aerosol loading in zone I and II, but only 20% in zone III. The effect of meteorological conditions such as temperature, relative humidity (RH) and wind on aerosol loadings over East China were also investigated.

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 (

Change Trends and Corresponding Meteorological Character of Air Pollition in Beijing

2011 ◽  
Vol 183-185 ◽  
pp. 1209-1214
Author(s):  
Hai Yan Ding ◽  
Xiao Ling Zhang ◽  
Wei Wei Pu ◽  
Di He
Keyword(s):  
Air Quality ◽  
Wind Speed ◽  
Meteorological Data ◽  
Pollution Index ◽  
Meteorological Conditions ◽  
Pollutant Concentration ◽  
North West ◽  
Average Value ◽  
The North ◽  
North Wind

Based on the monitoring data of air quality and meteorological data from 2003 to 2009 in Beijing, the change of air quality and pollutants concentration are analyzed, and their relationship with meteorological conditions are figured out. The results showed below.(1)The annual average value of API (Air Pollution Index) decreased from 2007 gradually, and the value of 2008 is equal to 86.3% of 2007. As to monthly changing trend of API, the value in April is highest, and is lowest in august. API in summer is lowest relatively in all-year, and it is worst in spring. (2)The pollutants concentration of PM2.5, SO2, NO2, and NOX showed decreasing trends from 2006 to 2009. The monthly changing trends of PM2.5, SO2, NO2, and O3 were different. The monthly average concentrations of NOX SO2, NO2 and NOX were lowest in July, while the high values appeared in different month.(3)Correlation between pollutant concentration and meteorological conditions are figured out: SO2, NO2 and NOX are negative related to temperature, wind speed and sunlight hours and positive related to humidity, while O3 is adverse. PM2.5 is well related to relative humidity and cloud cover. PM2.5, SO2, NO2 and NOX are all positive related to wind speed.(4)The air quality and pollutant concentration displayed significant in different under each wind direction. When north wind blows, the average value of API is lowest relatively and south wind is adverse. The concentration of PM2.5, SO2, NO2 and NOX are lower when Beijing is controlled by the north wind or north-west wind.

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.

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