Haze Days in North China and the associated atmospheric circulations based on daily visibility data from 1960 to 2012

2015 ◽  
Vol 120 (12) ◽  
pp. 5895-5909 ◽  
Author(s):  
Huopo Chen ◽  
Huijun Wang
Keyword(s):  
North China ◽  
Atmospheric Circulations ◽  
Haze Days

scholarly journals The Strengthening Relationship between Eurasian Snow Cover and December Haze Days in Central North China after the Mid-1990s

2017 ◽  
Author(s):  
Zhicong Yin ◽  
Huijun Wang
Keyword(s):  
Soil Moisture ◽  
Snow Cover ◽  
North China ◽  
Surface Wind ◽  
Surface Radiation ◽  
Radiative Cooling ◽  
Atmospheric Circulations ◽  
Haze Pollution ◽  
The Relationship ◽  
Haze Days

Abstract. The haze pollution in December has become increasingly serious over recent decades and imposes damage on society, ecosystems, and human health. In addition to anthropogenic emissions, climate change and variability were conducive to haze in China. In this study, the relationship between the snow cover over East Europe and West Siberia (SCES) and the number of haze days in December in central North China was analyzed. This relationship significantly strengthened after the mid-1990s, which is attributed to the effective connections between the SCES and the Eurasian atmospheric circulations. During 1998–2016, the SCES significantly influenced the soil moisture and land surface radiation, and then, the combined underlying drivers of enhanced soil moisture and radiative cooling moved the East Asia jet stream northward and induced anomalous, anti-cyclonic circulation over central North China. Modulated by such atmospheric circulations, the local lower boundary layer, the decreased surface wind and the more humid air were conducive to the worsening dispersion conditions and frequent haze occurrences. In contrast, from 1979 to 1997, the linkage between the SCES and soil moisture was negligible. Furthermore, the correlated radiative cooling was distributed narrowly and far from the key area of snow cover. The associated atmospheric circulations with the SCES were not significantly linked with the ventilation conditions over central North China. Consequently, the relationship between the SCES and the number of hazy days in central North China was insignificant before the mid-1990s but has strengthened and has become significant since then.

scholarly journals The strengthening relationship between Eurasian snow cover and December haze days in central North China after the mid-1990s

2018 ◽  
Vol 18 (7) ◽  
pp. 4753-4763 ◽  
Author(s):  
Zhicong Yin ◽  
Huijun Wang
Keyword(s):  
Soil Moisture ◽  
Snow Cover ◽  
North China ◽  
Surface Wind ◽  
Surface Radiation ◽  
Radiative Cooling ◽  
Atmospheric Circulations ◽  
Haze Pollution ◽  
The Relationship ◽  
Haze Days

Abstract. The haze pollution in December has become increasingly serious over recent decades and imposes damage on society, ecosystems, and human health. In addition to anthropogenic emissions, climate change and variability were conducive to haze in China. In this study, the relationship between the snow cover over eastern Europe and western Siberia (SCES) and the number of haze days in December in central North China was analyzed. This relationship significantly strengthened after the mid-1990s, which is attributed to the effective connections between the SCES and the Eurasian atmospheric circulations. During 1998–2016, the SCES significantly influenced the soil moisture and land surface radiation, and then the combined underlying drivers of enhanced soil moisture and radiative cooling moved the the East Asia jet stream northward and induced anomalous, anti-cyclonic circulation over central North China. Modulated by such atmospheric circulations, the local lower boundary layer, the decreased surface wind, and the more humid air were conducive to the worsening dispersion conditions and frequent haze occurrences. In contrast, from 1979 to 1997, the linkage between the SCES and soil moisture was negligible. Furthermore, the correlated radiative cooling was distributed narrowly and far from the key area of snow cover. The associated atmospheric circulations with the SCES were not significantly linked with the ventilation conditions over central North China. Consequently, the relationship between the SCES and the number of hazy days in central North China was insignificant before the mid-1990s but has strengthened and has become significant since then.

scholarly journals Understanding the Recent Trend of Haze Pollution in Eastern China: Roles of Climate Change

2016 ◽  
Author(s):  
H. J. Wang ◽  
H. P. Chen
Keyword(s):  
Energy Consumption ◽  
North China ◽  
Eastern China ◽  
Arctic Sea Ice ◽  
Total Energy Consumption ◽  
Sea Ice Extent ◽  
Haze Pollution ◽  
Arctic Sea ◽  
Haze Days ◽  
Arctic Sea Ice Extent

Abstract. In this paper, the variation and trend of haze pollution in eastern China for winter of 1960–2012 were analyzed. With the overall increasing number of winter haze days in the period, the five decades were divided into three sub-periods based on the changes of winter haze days (WHD) in central North China (30° N–40° N) and eastern South China (south of 30° N) for east of 109° E mainland China. Results show that WHD kept gradual increasing during 1960–1979, overall stable during 1980–1999, and fast increasing during 2000–2012. The author identified the major climate forcing factors besides total energy consumption. Among all the possible climate factors, variability of the autumn Arctic sea ice extent, local precipitation and surface wind during winter is most influential to the haze pollution change. The joint effect of fast increase of total energy consumption, rapid decline of Arctic sea ice extent and reduced precipitation and surface winds intensified the haze pollution in central North China after 2000. There is similar conclusion for haze pollution in eastern South China after 2000, with the precipitation effect being smaller and spatially inconsistent.

scholarly journals Melting of Perennial Sea Ice in the Beaufort Sea Enhanced Its Impacts on Early-Winter Haze Pollution in North China after the Mid-1990s

2020 ◽  
Vol 33 (12) ◽  
pp. 5061-5080 ◽  
Author(s):  
Yuyan Li ◽  
Zhicong Yin
Keyword(s):  
Sea Ice ◽  
North China ◽  
Beaufort Sea ◽  
Gulf Of Alaska ◽  
Ice Cover ◽  
Sea Surface ◽  
Haze Pollution ◽  
Sea Surface Temperature Anomalies ◽  
Haze Days ◽  
Perennial Ice

AbstractIn recent years, haze pollution has become the most concerning environmental issue in China due to its tremendous negative effects. In this study, we focus on the enhanced responses of December–January haze days in North China to September–October sea ice in the Beaufort Sea during 1998–2015. Via both observation and numerical approaches, compared with an earlier period (1980–97), the sea ice concentration in the Beaufort Sea presented large variability during 1998–2015. During 1980–97, the Beaufort Sea was mainly covered by perennial ice, and the ablation and freezing of sea ice mainly occurred at the south edge of the Beaufort Sea. Thus, heavy sea ice in autumn induced negative sea surface temperature anomalies across the Gulf of Alaska in November. However, the colder sea surface in the Gulf of Alaska only induced a weak influence on the haze-associated atmospheric circulations. In contrast, during 1998–2015, a drastic change in sea ice existed near the center of the Arctic Ocean, due to the massive melting of multiyear sea ice in the western Beaufort Sea. The perennial ice cover in the western Beaufort Sea was replaced by seasonal ice. The broader sea ice cover resulted in positive sea surface temperature anomalies in the following November. Then, suitable atmospheric backgrounds were induced for haze pollution in December and January. Simultaneously, the response of the number of haze days over North China to sea ice cover increased. These findings were verified by the CESM-LE simulations and aided in deepening the understanding of the cause of haze pollution.

scholarly journals Dominant patterns of summer ozone pollution in eastern China and associated atmospheric circulations

2019 ◽  
Vol 19 (22) ◽  
pp. 13933-13943 ◽  
Author(s):  
Zhicong Yin ◽  
Bufan Cao ◽  
Huijun Wang
Keyword(s):  
North China ◽  
Surface Ozone ◽  
Eastern China ◽  
Western Pacific Subtropical High ◽  
Ground Level ◽  
Photochemical Reactions ◽  
Western Pacific ◽  
Subtropical High ◽  
Ozone Pollution ◽  
Atmospheric Circulations

Abstract. Surface ozone has been severe during summers in the eastern parts of China, damaging human health and flora and fauna. During 2015–2018, ground-level ozone pollution increased and intensified from south to north. In North China and the Huanghuai region, the O3 concentrations were highest. Two dominant patterns of summer ozone pollution were determined, i.e., a south–north covariant pattern and a south–north differential pattern. The anomalous atmospheric circulations composited for the first pattern manifested as a zonally enhanced East Asian deep trough and as a western Pacific subtropical high, whose western ridge point shifted northward. The local hot, dry air and intense solar radiation enhanced the photochemical reactions to elevate the O3 pollution levels in North China and the Huanghuai region; however, the removal of pollutants was decreased. For the second pattern, the broad positive geopotential height anomalies at high latitudes significantly weakened cold air advection from the north, and those extending to North China resulted in locally high temperatures near the surface. In a different manner, the western Pacific subtropical high transported sufficient water vapor to the Yangtze River Delta and resulted in a locally adverse environment for the formation of surface ozone. In addition, the most dominant pattern in 2017 and 2018 was different from that in previous years, which is investigated as a new feature.

scholarly journals Observation of atmospheric peroxides during Wangdu Campaign 2014 at a rural site in the North China Plain

2016 ◽  
Vol 16 (17) ◽  
pp. 10985-11000 ◽  
Author(s):  
Yin Wang ◽  
Zhongming Chen ◽  
Qinqin Wu ◽  
Hao Liang ◽  
Liubin Huang ◽  
...  
Keyword(s):  
Biomass Burning ◽  
North China Plain ◽  
North China ◽  
Chemical Mechanism ◽  
Rural Site ◽  
Direct Production ◽  
The North ◽  
The North China Plain ◽  
The Impact ◽  
Haze Days

Abstract. Measurements of atmospheric peroxides were made during Wangdu Campaign 2014 at Wangdu, a rural site in the North China Plain (NCP) in summer 2014. The predominant peroxides were detected to be hydrogen peroxide (H2O2), methyl hydroperoxide (MHP) and peroxyacetic acid (PAA). The observed H2O2 reached up to 11.3 ppbv, which was the highest value compared with previous observations in China at summer time. A box model simulation based on the Master Chemical Mechanism and constrained by the simultaneous observations of physical parameters and chemical species was performed to explore the chemical budget of atmospheric peroxides. Photochemical oxidation of alkenes was found to be the major secondary formation pathway of atmospheric peroxides, while contributions from alkanes and aromatics were of minor importance. The comparison of modeled and measured peroxide concentrations revealed an underestimation during biomass burning events and an overestimation on haze days, which were ascribed to the direct production of peroxides from biomass burning and the heterogeneous uptake of peroxides by aerosols, respectively. The strengths of the primary emissions from biomass burning were on the same order of the known secondary production rates of atmospheric peroxides during the biomass burning events. The heterogeneous process on aerosol particles was suggested to be the predominant sink for atmospheric peroxides. The atmospheric lifetime of peroxides on haze days in summer in the NCP was about 2–3 h, which is in good agreement with the laboratory studies. Further comprehensive investigations are necessary to better understand the impact of biomass burning and heterogeneous uptake on the concentration of peroxides in the atmosphere.

scholarly journals Seasonal prediction of winter haze days in the north central North China Plain

2016 ◽  
Vol 16 (23) ◽  
pp. 14843-14852 ◽  
Author(s):  
Zhicong Yin ◽  
Huijun Wang
Keyword(s):  
Prediction Model ◽  
North China Plain ◽  
North China ◽  
Additive Model ◽  
Continuous Increase ◽  
North Central ◽  
The North ◽  
Predictive Skill ◽  
Haze Pollution ◽  
Haze Days

Abstract. Recently, the winter (December–February) haze pollution over the north central North China Plain (NCP) has become severe. By treating the year-to-year increment as the predictand, two new statistical schemes were established using the multiple linear regression (MLR) and the generalized additive model (GAM). By analyzing the associated increment of atmospheric circulation, seven leading predictors were selected to predict the upcoming winter haze days over the NCP (WHDNCP). After cross validation, the root mean square error and explained variance of the MLR (GAM) prediction model was 3.39 (3.38) and 53 % (54 %), respectively. For the final predicted WHDNCP, both of these models could capture the interannual and interdecadal trends and the extremums successfully. Independent prediction tests for 2014 and 2015 also confirmed the good predictive skill of the new schemes. The predicted bias of the MLR (GAM) prediction model in 2014 and 2015 was 0.09 (−0.07) and −3.33 (−1.01), respectively. Compared to the MLR model, the GAM model had a higher predictive skill in reproducing the rapid and continuous increase of WHDNCP after 2010.

Effect of potential HONO sources on ROx budgets and SOA and PAN formation in North China in winter

2020 ◽  
Author(s):  
Jingwei Zhang ◽  
Junling An
Keyword(s):  
Nitrous Acid ◽  
North China ◽  
Heterogeneous Reaction ◽  
Chemical Transport ◽  
Heterogeneous Reactions ◽  
Transport Models ◽  
Chemical Transport Models ◽  
High Concentrations ◽  
Haze Days ◽  
Bth Region

<p>Recent wintertime observations in north China found high concentrations of nitrous acid (HONO), secondary organic aerosols (SOA) and peroxyacetyl nitrate (PAN), especially during heavy haze periods, indicating stronger atmospheric oxidation capacity in winter haze days. Researchers speculated that HONO formation was enhanced in haze days through NO<sub>2</sub> heterogeneous reaction on aerosol surfaces, and high concentrations of HONO during daytime further improved SOA and PAN formation.</p><p>In this study, the WRF-Chem model updated with six potential HONO sources was used to quantify the impacts of potential HONO sources on the production and loss rates of RO<sub>x</sub> ( OH+HO<sub>2</sub>+RO<sub>2</sub>) radicals, and on the concentrations of SOA and PAN in the Beijing-Tianjin-Hebei (BTH) region of China during wintertime of 2017. HONO simulations were greatly improved after considering the six potential sources, NO<sub>2</sub> heterogeneous reactions were the main sources of HONO. HONO photolysis was the key precursors of primary OH while the contribution of O<sub>3</sub> photolysis to OH could be neglected, the potential HONO sources remarkably accelerated RO<sub>x</sub> cycles, significantly improved SOA and PAN simulations, especially in heavy polluted periods. The above results suggest that the potential HONO sources should be considered in regional and global chemical transport models when conducting relevant studies.</p>

scholarly journals Haze pollution in winter and summer in Zibo, a heavily industrialized city neighboring the Jin-Jin-Ji area of China: source, formation, and implications

2018 ◽  
Author(s):  
Hui Li ◽  
Fengkui Duan ◽  
Yongliang Ma ◽  
Kebin He ◽  
Lidan Zhu ◽  
...  
Keyword(s):  
North China ◽  
Control Policy ◽  
Photochemical Activity ◽  
Heterogeneous Reactions ◽  
Air Pollution Control ◽  
The North ◽  
Haze Pollution ◽  
High Concentrations ◽  
Pollution Control Policy ◽  
Haze Days

Abstract. Continuous field observations of haze pollution were conducted in winter and summer during 2015 in Zibo, a highly industrialized city in the North China Plain that is adjacent to the Jing-Jin-Ji area. PM2.5 concentration averaged 146.7 ± 85.8 and 82.2 ± 44.3 μg m−3 in winter and summer, respectively. The chemical component contributions to PM2.5 showed obvious seasonal variation. Organics were high in winter, but secondary inorganic aerosols (SIA) were high in summer. From non-haze to haze days, the concentration of SIA increased, implying an important role of secondary processes in the evolution process of the pollution. The diurnal behavior of several pollutants during haze days appeared to fluctuate more, but during non-haze days, it was much more stable, suggesting that complex mechanisms are involved. Specifically, gaseous precursors, mixed layer height (MLH), photochemical activity, and relative humidity (RH) also played important roles in the diurnal variation of the pollutants. Normally, larger gaseous precursor concentrations, photochemical activity, and RH, and lower MLH favored high concentrations. In winter, the formation of sulfate was mainly influenced by RH, indicating the importance of heterogeneous reactions in its formation. In contrast, in summer, photochemistry and SO2 concentration had the largest impact on the sulfate level. We found that Zibo was an ammonia-rich city, especially in winter, meaning that the formation of nitrate was through homogeneous reactions between HNO3 and NH3 in the gas phase, followed by partitioning into the particle phase. The RH, NO2, and Excess NH4+ were the main influencing factors for nitrate in winter, whereas Excess NH4+, RH, and temperature were the key factors in summer. The secondary organic carbon (SOC) level depended on the MLH and photochemistry. In winter, the effect of the MLH was stronger than that of photochemistry, but a reversed situation occurred in summer because of the intensive photochemistry. Our work suggested that the inter-transport between Zibo, one of the most polluted cities in north China, and its adjacent areas should be taken into account when formulating air pollution control policy.

Sign in / Sign up

Export Citation Format

Share Document