Review for “Dominant patters of summer ozone pollution in Eastern China and associated 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.

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Dominant Patterns of Summer Ozone Pollution in Eastern China and Associated Atmospheric Circulations

10.5194/acp-2019-430 ◽

2019 ◽

Author(s):

Zhicong Yin ◽

Bufan Cao ◽

Huijun Wang

Keyword(s):

North China ◽

Surface Ozone ◽

Eastern China ◽

Photochemical Reactions ◽

Air Pollutant ◽

Subtropical High ◽

Ozone Pollution ◽

West Pacific ◽

Atmospheric Circulations ◽

West Pacific Subtropical High

Abstract. Surface ozone, a man-made air pollutant, has been severe during summers in the eastern parts of China, damaging human’s health and flora and fauna. During 2015–2018, ground-level ozone pollution increased year by year and intensified from south to north. In North China and 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 Asia deep trough and as a west 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 Huanghuai region. For the second pattern, the broad positive geopotential height anomalies at high latitudes significantly weakened cold air activity, and those extending to North China resulted in locally high temperature near the surface. In a different manner, the west Pacific subtropical high transported sufficient water vapor to the Yangtze River Delta and resulted in locally adverse environment for the formation of surface ozone. Furthermore, the implications for the interannual differences in summer O3 pollution have also proven to be meaningful.

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Review of “Impact of western pacific subtropical high on ozone pollution over eastern china”

10.5194/acp-2020-646-rc2 ◽

2020 ◽

Author(s):

Anonymous

Keyword(s):

Eastern China ◽

Western Pacific Subtropical High ◽

Western Pacific ◽

Subtropical High ◽

Ozone Pollution

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Comparison of temporal and Spatial Characteristics of Ozone Pollution at Ground Level in the Eastern China

Chinese Journal of Population Resources and Environment ◽

10.1080/10042857.2006.10677466 ◽

2006 ◽

Vol 4 (3) ◽

pp. 51-57

Author(s):

Liu Houfeng

Keyword(s):

Eastern China ◽

Ground Level ◽

Ozone Pollution ◽

Spatial Characteristics ◽

Temporal And Spatial ◽

Temporal And Spatial Characteristics

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Unexpected Fast Monoterpene Oxidation In Eastern China

10.5194/egusphere-egu21-15908 ◽

2021 ◽

Author(s):

Haichao Wang

Keyword(s):

Eastern China ◽

Field Measurements ◽

Ozone Production ◽

Nitrate Radical ◽

Peroxy Radicals ◽

Ozone Pollution ◽

Volatile Organic ◽

Secondary Aerosols ◽

Photochemical Ozone

<p>Monoterpene plays an important role in the formation of secondary aerosols and ozone in the troposphere. However, the field characterization of monoterpene chemistry in ozone pollution is still very sparse. Here we report fast daytime oxidation of monoterpene by hydroxyl radical, nitrate radical and ozone based on field measurements in Eastern China. We find fast monoterpene oxidation produces peroxy radicals efficiently and enhances the photochemical ozone production largely with an additional 8.6 ppb of ozone production per day on average (14%), whose effect was even more important than that of isoprene chemistry in the analyzed dataset. We propose that the reduction of anthropogenic volatile organic compounds should be much more stringent in the presence of high monoterpenes to alleviating ozone pollution.</p>

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Local and synoptic meteorological influences on daily variability in summertime surface ozone in eastern China

Atmospheric Chemistry and Physics ◽

10.5194/acp-20-203-2020 ◽

2020 ◽

Vol 20 (1) ◽

pp. 203-222 ◽

Cited By ~ 11

Author(s):

Han Han ◽

Jane Liu ◽

Lei Shu ◽

Tijian Wang ◽

Huiling Yuan

Keyword(s):

Surface Ozone ◽

Eastern China ◽

River Delta ◽

Daily Maximum ◽

Ozone Pollution ◽

Study Region ◽

Synoptic Weather ◽

Daily Variability ◽

Influential Variable ◽

The Impact

Abstract. Ozone pollution in China is influenced by meteorological processes on multiple scales. Using regression analysis and weather classification, we statistically assess the impacts of local and synoptic meteorology on daily variability in surface ozone in eastern China in summer during 2013–2018. In this period, summertime surface ozone in eastern China (20–42∘ N, 110–130∘ E) is among the highest in the world, with regional means of 73.1 and 114.7 µg m−3, respectively, in daily mean and daily maximum 8 h average. Through developing a multiple linear regression (MLR) model driven by local and synoptic weather factors, we establish a quantitative linkage between the daily mean ozone concentrations and meteorology in the study region. The meteorology described by the MLR can explain ∼43 % of the daily variability in summertime surface ozone across eastern China. Among local meteorological factors, relative humidity is the most influential variable in the center and south of eastern China, including the Yangtze River Delta and the Pearl River Delta regions, while temperature is the most influential variable in the north, covering the Beijing–Tianjin–Hebei region. To further examine the synoptic influence of weather conditions explicitly, six predominant synoptic weather patterns (SWPs) over eastern China in summer are objectively identified using the self-organizing map clustering technique. The six SWPs are formed under the integral influence of the East Asian summer monsoon, the western Pacific subtropical high, the Meiyu front, and the typhoon activities. On average, regionally, two SWPs bring about positive ozone anomalies (1.1 µg m−3 or 1.7 % and 2.7 µg m−3 or 4.6 %), when eastern China is under a weak cyclone system or under the prevailing southerly wind. The impact of SWPs on the daily variability in surface ozone varies largely within eastern China. The maximum impact can reach ±8 µg m−3 or ±16 % of the daily mean in some areas. A combination of the regression and the clustering approaches suggests a strong performance of the MLR in predicting the sensitivity of surface ozone in eastern China to the variation of synoptic weather. Our assessment highlights the importance of meteorology in modulating ozone pollution over China.

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Ozone seasonal evolution and photochemical production regime in polluted troposphere in eastern China derived from high resolution FTS observations

10.5194/acp-2017-1176 ◽

2017 ◽

Cited By ~ 1

Author(s):

Youwen Sun ◽

Cheng Liu ◽

Mathias Palm ◽

Corinne Vigouroux ◽

Qihou Hu ◽

...

Keyword(s):

Tropospheric Ozone ◽

Meteorological Data ◽

Eastern China ◽

Ozone Production ◽

Ozone Pollution ◽

Seasonal Evolution ◽

Photochemical Production ◽

Production Regime ◽

Autumn And Winter ◽

Ozone Levels

Abstract. A precise knowledge of ozone seasonal evolution and photochemical production regime in polluted troposphere in China has important policy implications for ozone pollution controls especially in megacities where ozone pollution is common throughout the year. In this study, we used tropospheric ozone, CO and HCHO columns derived from high resolution Fourier transform infrared spectrometry (FTS) in Hefei, China, tropospheric NO2 columns deduced from overpass Ozone Monitoring Instrument (OMI), surface meteorological data, and a back trajectory cluster analysis technique to investigate ozone seasonal evolution and photochemical production regime in eastern China from 2014–2017. A pronounced seasonal cycle for tropospheric ozone is captured by FTS, where high levels of tropospheric ozone occurs in spring and summer, and low levels of tropospheric ozone occurs in autumn and winter. Day-to-day variations in spring and summer are in most cases larger than those in autumn and winter. At the same time, it shows that the tropospheric ozone roughly increases over time at the first half year and reaches the maximum in June, and then it decreases over time at the second half year. Tropospheric ozone columns in June are, on average, 0.5×1018 molecules*cm−2 (47.6 %) higher than those in December which has a mean value of 1.05×1018 molecules*cm−2. The OMI time series shows similar behaviour. The measured features can basically be reproduced by GEOS-Chem and WRF-Chem data but with slight shifts in the timing of the seasonal maximum. Back trajectories analysis shows that: air pollutions in megacities in central-southern China, northwest China, and the key pollution area, i.e., Yangtze River Delta area in eastern China, dominates the contributions to the observed tropospheric ozone levels, while the contributions from the other two key pollution areas, i.e., Beijing-Tianjin-Hebei in north China and Pearl River Delta in south China, are very small; Air masses generated from polluted areas have more transportations to the observed area in spring and summer than in autumn and winter, and hence have more contributions to the observed tropospheric ozone levels. Correlations between tropospheric ozone and meteorological data disclosed that spring and summer is more favorable to photochemical ozone production than in autumn and winter. Finally, the HCHO/NO2 ratio is used as a proxy to investigate the chemical sensitivity of ozone production (PO3). The results show that the PO3 is mainly NOx limited in summer, while it is mainly VOC or mix VOC-NOx limited in winter. Statistics show that NOx limited, mix VOC-NOx limited, and VOC limited PO3 accounts for 60.1 %, 28.7 %, and 11 %, respectively.

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Widespread and Persistent Ozone Pollution in Eastern China

10.5194/acp-2016-864 ◽

2016 ◽

Cited By ~ 1

Author(s):

Guohui Li ◽

Naifang Bei ◽

Junji Cao ◽

Jiarui Wu ◽

Xin Long ◽

...

Keyword(s):

Control Strategies ◽

Action Plan ◽

Eastern China ◽

Pollution Prevention ◽

Temporal Variations ◽

Anthropogenic Sources ◽

Daily Maximum ◽

Ozone Pollution ◽

Near Surface ◽

Model Studies

Abstract. Rapid growth of industrialization, transportation, and urbanization has caused increasing emissions of ozone (O3) precursors recently, enhancing the O3 formation in Eastern China. We show here that Eastern China has experienced widespread and persistent O3 pollution from April to September in 2015 based on the O3 observations in 223 cities. The observed maximum 1-h O3 concentrations exceed 200 μg m−3 in almost all the cities, 400 μg m−3 in more than 25 % of the cities, and even 800 μg m−3 in six cities in Eastern China. The average daily maximum 1-h O3 concentrations are more than 160 μg m−3 in 45 % of the cities, and the 1-h O3 concentrations of 200 μg m−3 have been exceeded on over 10 % of days from April to September in 129 cities. A widespread and severe O3 pollution episode from 22 to 28 May 2015 in Eastern China has been simulated using the WRF-CHEM model to evaluate the O3 contribution of biogenic and various anthropogenic sources. The model generally performs reasonably well in simulating the temporal variations and spatial distributions of near-surface O3 concentrations. Using the factor separate approach, sensitivity studies have indicated that the industry source plays the most important role in the O3 formation, and constitutes the culprit of the severe O3 pollution in Eastern China. The transportation source contributes considerably to the O3 formation, and the O3 contribution of the residential source is not significant generally. The biogenic source provides a background O3 source, and also plays an important role in the south of Eastern China. Further model studies are needed to comprehensively investigate O3 formation for supporting the design and implementation of O3 control strategies, considering rapid changes of emissions inventories and photolysis caused by the "Atmospheric Pollution Prevention and Control Action Plan", released by the Chinese State Council in 2013.

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