The analysis of the haze event in the North China plain in 2013

Abstract. Accurate identification and quantitative source apportionment of fine particulate matters (PM2.5) provide an important prerequisite for design and implementation of emission control strategies to reduce PM pollution. Therefore, a source-oriented version of the WRF-Chem model is developed in the study to make source apportionment of PM2.5 in the North China Plain (NCP). A persistent and heavy haze event occurred in the NCP from 05 December 2015 to 04 January 2016 is simulated using the model as a case study to quantify PM2.5 contributions of local emissions and regional transport. Results show that local and non-local emissions contribute 36.3 % and 63.7 % of the PM2.5 mass in Beijing during the haze event on average. When Beijing's air quality is excellent or good in terms of hourly PM2.5 concentrations, local emissions dominate the PM2.5 mass with contributions exceeding 50 %. However, when the air quality is severely polluted, the PM2.5 contribution of non-local emissions is around 75 %. The non-local emissions also dominate the Tianjin's air quality, with average PM2.5 contributions exceeding 70 %. The PM2.5 level in Hebei and Shandong is generally controlled by local emissions, but in Henan, local and non-local emissions play an almost equivalent role in the PM2.5 level, except when the air quality is severely polluted, with non-local PM2.5 contributions of over 60 %. Additionally, the primary aerosol species are generally dominated by local emissions with the average contribution exceeding 50%. However, the source apportionment of secondary aerosols shows more evident regional characteristics. Therefore, except cooperation with neighboring provinces to carry out strict emission mitigation measures, reducing primary aerosols constitutes the priority to alleviate PM pollution in the NCP, especially in Beijing and Tianjin.

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Modeling study of the 2010 regional haze event in the North China Plain

Atmospheric Chemistry and Physics Discussions ◽

10.5194/acpd-15-22781-2015 ◽

2015 ◽

Vol 15 (16) ◽

pp. 22781-22822 ◽

Cited By ~ 8

Author(s):

M. Gao ◽

G. R. Carmichael ◽

Y. Wang ◽

P. E. Saide ◽

M. Yu ◽

...

Keyword(s):

Air Pollutants ◽

North China Plain ◽

North China ◽

Weather Conditions ◽

Air Pollution Control ◽

Wind Speeds ◽

The North ◽

The North China Plain ◽

Haze Event ◽

Regional Haze

Abstract. The online coupled Weather Research and Forecasting-Chemistry (WRF-Chem) model was applied to simulate a haze event that happened in January 2010 in the North China Plain (NCP), and was validated against various types of measurements. The evaluations indicate that WRF-Chem provides reliable simulations for the 2010 haze event in the NCP. This haze event is mainly caused by high emissions of air pollutants in the NCP and stable weather conditions in winter. Secondary inorganic aerosols also played an important role and cloud chemistry had important contributions. Air pollutants outside Beijing contributed about 47.8 % to the PM2.5 levels in Beijing during this haze event, and most of them are from south Hebei, Shandong and Henan provinces. In addition, aerosol feedback has important impacts on surface temperature, Relative Humidity (RH) and wind speeds, and these meteorological variables affect aerosol distribution and formation in turn. In Shijiazhuang, Planetary Boundary Layer (PBL) decreased about 300 m and PM2.5 increased more than 20 μg m-3 due to aerosol feedback. Feedbacks associated to Black Carbon (BC) account for about 50 % of the PM2.5 increases and 50 % of the PBL decreases in Shijiazhuang, indicating more attention should be paid to BC from both air pollution control and climate change perspectives.

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Surface Energy Budget Observed for Winter Wheat in the North China Plain During a Fog–Haze Event

Boundary-Layer Meteorology ◽

10.1007/s10546-018-0407-x ◽

2018 ◽

Vol 170 (3) ◽

pp. 489-505 ◽

Cited By ~ 3

Author(s):

Changwei Liu ◽

Zhiqiu Gao ◽

Yubin Li ◽

Chloe Y. Gao ◽

Zhongbo Su ◽

...

Keyword(s):

Surface Energy ◽

Winter Wheat ◽

Energy Budget ◽

North China Plain ◽

North China ◽

Surface Energy Budget ◽

The North ◽

The North China Plain ◽

Haze Event

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Modeling the feedback between aerosol and meteorological variables in the atmospheric boundary layer during a severe fog–haze event over the North China Plain

Atmospheric Chemistry and Physics ◽

10.5194/acp-15-4279-2015 ◽

2015 ◽

Vol 15 (8) ◽

pp. 4279-4295 ◽

Cited By ~ 106

Author(s):

Y. Gao ◽

M. Zhang ◽

Z. Liu ◽

L. Wang ◽

P. Wang ◽

...

Keyword(s):

Boundary Layer ◽

Radiative Forcing ◽

Numerical Experiments ◽

North China Plain ◽

North China ◽

Meteorological Variables ◽

The North ◽

The North China Plain ◽

Haze Event ◽

Pm2.5 Concentration

Abstract. The feedback between aerosol and meteorological variables in the atmospheric boundary layer over the North China Plain (NCP) is analyzed by conducting numerical experiments with and without the aerosol direct and indirect effects via a coupled meteorology and aerosol/chemistry model (WRF-Chem). The numerical experiments are performed for the period of 2–26 January 2013, during which a severe fog–haze event (10–15 January 2013) occurred, with the simulated maximum hourly surface PM2.5 concentration of ~600 ug m−3, minimum atmospheric visibility of ~0.3 km, and 10–100 hours of simulated hourly surface PM2.5 concentration above 300 ug m−3 over NCP. A comparison of model results with aerosol feedback against observations indicates that the model can reproduce the spatial and temporal characteristics of temperature, relative humidity (RH), wind, surface PM2.5 concentration, atmospheric visibility, and aerosol optical depth reasonably well. Analysis of model results with and without aerosol feedback shows that during the fog–haze event aerosols lead to a significant negative radiative forcing of −20 to −140 W m−2 at the surface and a large positive radiative forcing of 20–120 W m−2 in the atmosphere and induce significant changes in meteorological variables with maximum changes during 09:00–18:00 local time (LT) over urban Beijing and Tianjin and south Hebei: the temperature decreases by 0.8–2.8 °C at the surface and increases by 0.1–0.5 °C at around 925 hPa, while RH increases by about 4–12% at the surface and decreases by 1–6% at around 925 hPa. As a result, the aerosol-induced equivalent potential temperature profile change shows that the atmosphere is much more stable and thus the surface wind speed decreases by up to 0.3 m s−1 (10%) and the atmosphere boundary layer height decreases by 40–200 m (5–30%) during the daytime of this severe fog–haze event. Owing to this more stable atmosphere during 09:00–18:00, 10–15~January, compared to the surface PM2.5 concentration from the model results without aerosol feedback, the average surface PM2.5 concentration increases by 10–50 μg m−3 (2–30%) over Beijing, Tianjin, and south Hebei and the maximum increase of hourly surface PM2.5 concentration is around 50 (70%), 90 (60%), and 80 μg m−3 (40%) over Beijing, Tianjin, and south Hebei, respectively. Although the aerosol concentration is maximum at nighttime, the mechanism of feedback, by which meteorological variables increase the aerosol concentration most, occurs during the daytime (around 10:00 and 16:00 LT). The results suggest that aerosol induces a more stable atmosphere, which is favorable for the accumulation of air pollutants, and thus contributes to the formation of fog–haze events.

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Insights into particulate matter pollution in the North China Plain during wintertime: local contribution or regional transport?

Atmospheric Chemistry and Physics ◽

10.5194/acp-21-2229-2021 ◽

2021 ◽

Vol 21 (3) ◽

pp. 2229-2249

Author(s):

Jiarui Wu ◽

Naifang Bei ◽

Yuan Wang ◽

Xia Li ◽

Suixin Liu ◽

...

Keyword(s):

Particulate Matter ◽

Air Quality ◽

Source Apportionment ◽

North China Plain ◽

North China ◽

Regional Transport ◽

The North ◽

The North China Plain ◽

Haze Event ◽

Local Emissions

Abstract. Accurate identification and quantitative source apportionment of fine particulate matter (PM2.5) provide an important prerequisite for design and implementation of emission control strategies to reduce PM pollution. Therefore, a source-oriented version of the WRF-Chem model is developed in the study to conduct source apportionment of PM2.5 in the North China Plain (NCP). A persistent and heavy haze event that occurred in the NCP from 5 December 2015 to 4 January 2016 is simulated using the model as a case study to quantify PM2.5 contributions of local emissions and regional transport. Results show that local and nonlocal emissions contribute 36.3 % and 63.7 % of the PM2.5 mass in Beijing during the haze event on average. When Beijing's air quality is excellent or good in terms of hourly PM2.5 concentrations, local emissions dominate the PM2.5 mass, with contributions exceeding 50 %. However, when the air quality is severely polluted, the PM2.5 contribution of nonlocal emissions is around 75 %. Nonlocal emissions also dominate Tianjin's air quality, with average PM2.5 contributions exceeding 65 %. The PM2.5 level in Hebei and Shandong is generally controlled by local emissions, but in Henan, local and nonlocal emissions play an almost equivalent role in the PM2.5 level, except when the air quality is severely polluted, with nonlocal PM2.5 contributions of over 60 %. Additionally, the primary aerosol species are generally dominated by local emissions, with the average contribution exceeding 50 %. However, the source apportionment of secondary aerosols shows more evident regional characteristics. Therefore, except for cooperation with neighboring provinces to carry out strict emission mitigation measures, reducing primary aerosols is a priority to alleviate PM pollution in the NCP, especially in Beijing and Tianjin.

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Modeling the feedback between aerosol and meteorological variables in the atmospheric boundary layer during a severe fog-haze event over the North China Plain

Atmospheric Chemistry and Physics Discussions ◽

10.5194/acpd-15-1093-2015 ◽

2015 ◽

Vol 15 (1) ◽

pp. 1093-1130 ◽

Cited By ~ 15

Author(s):

Y. Gao ◽

M. Zhang ◽

Z. Liu ◽

L. Wang ◽

P. Wang ◽

...

Keyword(s):

Boundary Layer ◽

Radiative Forcing ◽

North China Plain ◽

North China ◽

Hebei Province ◽

Meteorological Variables ◽

The North ◽

The North China Plain ◽

Haze Event ◽

Pm2.5 Concentration

Abstract. The feedback between aerosol and meteorological variables in the atmospheric boundary layer over the North China Plain is analyzed by conducting numerical experiments with and without the aerosol direct and indirect effects via a coupled meteorology and aerosol/chemistry model (WRF-Chem). The numerical experiments are performed for the period 2–26 January 2013, during which a severe fog-haze event (10–15 January 2013) occurred. Comparison of the model results with aerosol feedback against observations indicates that the model can reproduce the spatial and temporal characteristics of temperature, relative humidity (RH), wind, surface PM2.5 concentration, atmospheric visibility, and aerosol optical depth. Comparison of modeling results in the presence and absence of aerosol feedback during the fog-haze event shows that aerosols lead to a significant negative radiative forcing of −20 to −140 W m−2 at the surface and a large positive radiative forcing of 20–120 W m−2 in the atmosphere and induce significant changes in meteorological variables of which the maximum changes occur during 09:00–18:00 LT over urban Beijing and Tianjin, and south Hebei Province: the temperature decreases by 0.8–2.8 °C at the surface and increases by 0.1–0.5 °C at around 925 hPa while the RH increases by about 4–12% at the surface and decreases by 1–6% at around 925 hPa. As a result, the aerosol-induced equivalent potential temperature profile change shows that the atmosphere is much more stable and thus the surface wind speed decreases by up to 0.3 m s−1 (10%) and the atmosphere boundary layer height decreases by 40–200 m (5–30%) during the daytime of this severe fog-haze event. Owing to this more stable atmosphere, during 09:00–18:00, 10–15 January, compared to the surface PM2.5 concentration from the model results without aerosol feedback, the average surface PM2.5 concentration increases by 10–50 μg m−3 (2–30%) over Beijing, Tianjin, and south Hebei province and the maximum increase of hourly surface PM2.5 concentration is around 50 μg m−3 (70%), 90 μg m−3 (60%) and 80 μg m−3 (40%), averaged over Beijing, Tianjin and south Hebei Province, respectively. Although the aerosol concentration is maximum at nighttime, the mechanism of feedback by which meteorological variables increase the aerosol concentration most occurs during the daytime (around 10:00 and 16:00). The results suggest that aerosol induces a more stable atmosphere, which is favorable for the accumulation of air pollutants, and thus contributes to the formation of fog-haze events.

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Modeling study of the 2010 regional haze event in the North China Plain

Atmospheric Chemistry and Physics ◽

10.5194/acp-16-1673-2016 ◽

2016 ◽

Vol 16 (3) ◽

pp. 1673-1691 ◽

Cited By ~ 89

Author(s):

M. Gao ◽

G. R. Carmichael ◽

Y. Wang ◽

P. E. Saide ◽

M. Yu ◽

...

Keyword(s):

Air Pollutants ◽

North China Plain ◽

North China ◽

Weather Conditions ◽

Air Pollution Control ◽

Wind Speeds ◽

The North ◽

The North China Plain ◽

Haze Event ◽

Tianjin City

Abstract. The online coupled Weather Research and Forecasting-Chemistry (WRF-Chem) model was applied to simulate a haze event that happened in January 2010 in the North China Plain (NCP), and was validated against various types of measurements. The evaluations indicate that WRF-Chem provides reliable simulations for the 2010 haze event in the NCP. This haze event was mainly caused by high emissions of air pollutants in the NCP and stable weather conditions in winter. Secondary inorganic aerosols also played an important role and cloud chemistry had important contributions. Air pollutants outside Beijing contributed about 64.5 % to the PM2.5 levels in Beijing during this haze event, and most of them are from south Hebei, Tianjin city, Shandong and Henan provinces. In addition, aerosol feedback has important impacts on surface temperature, relative humidity (RH) and wind speeds, and these meteorological variables affect aerosol distribution and formation in turn. In Shijiazhuang, Planetary Boundary Layer (PBL) decreased about 278.2 m and PM2.5 increased more than 20 µg m−3 due to aerosol feedback. It was also shown that black carbon (BC) absorption has significant impacts on meteorology and air quality changes, indicating more attention should be paid to BC from both air pollution control and climate change perspectives.

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