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Atmosphere
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Remote Sensing and Multiple Observations of Air Quality in China
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Remote Sensing and Multiple Observations of Air Quality in China

A special issue of Atmosphere (ISSN 2073-4433). This special issue belongs to the section "Air Quality".

Deadline for manuscript submissions: closed (30 April 2023) | Viewed by 14641

Special Issue Editors

Dr. Junli Jin

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Guest Editor
Meteorological Observation Center, China Meteorological Administration, Beijing 100081, China
Interests: reactive and greenhouse gases; long-term variation trends; climate change and evaluation; vertical distribution observation; MAX-DOAS; ozone sounding
Dr. Dongqing Fang

E-Mail
Guest Editor
Meteorological Observation Center，China Meteorological Administration, Beijing 100081, China
Interests: aerosol; chemical characterization and source apportionment; reactive oxygen species; oxidative potential; risk assessments; health effects
Dr. Mengyun Lou

E-Mail
Guest Editor
Meteorological Observation Center，China Meteorological Administration, Beijing 100081, China
Interests: aerosol pollution; planetary boundary layer; aerosol–PBL feedback; aerosol long-distance transport

Special Issue Information

Dear Colleagues,

The rapid economic growth and urbanisation that have been ongoing for more than four decades have led to dramatic changes to atmospheric compositions and characteristics in China, driving various environmental and climate problems on different temporal and spatial scales. Fortunately, a series of policies and measures have been implemented by the Chinese government to control atmospheric pollution emissions and restore the ecosystem, contributing greatly to ameliorating the air quality. Additionally, COVID-19 related shutdown and quarantines have offered a rare opportunity to observe and evaluate the variation characteristics and influencing factors of air quality. As such, it is of great importance and value to study the temporal and spatial distribution and variation characteristics of key indexes of air quality at regional and national scale, based on multiple observation and analysis techniques.

The aim of this Special Issue hosted by the open-access journal Atmosphere is to improve our knowledge of major advances, findings and insights of key indexes of air quality across China. The topics cover all related research fields, including but not limited to: research and investigation on the temporal and spatial distribution and variation characteristics of aerosol particles, optical properties, visual obstruction phenomena, haze-fog, acid rain, ozone and precursors, photochemical pollution, etc. Developments, applications and evaluations of new remote sensing and other observation techniques are welcome.

Dr. Junli Jin
Dr. Dongqing Fang
Dr. Mengyun Lou
Guest Editors

Manuscript Submission Information

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Submitted manuscripts should not have been published previously, nor be under consideration for publication elsewhere (except conference proceedings papers). All manuscripts are thoroughly refereed through a single-blind peer-review process. A guide for authors and other relevant information for submission of manuscripts is available on the Instructions for Authors page. Atmosphere is an international peer-reviewed open access monthly journal published by MDPI.

Please visit the Instructions for Authors page before submitting a manuscript. The Article Processing Charge (APC) for publication in this open access journal is 2400 CHF (Swiss Francs). Submitted papers should be well formatted and use good English. Authors may use MDPI's English editing service prior to publication or during author revisions.

Keywords

  • air quality
  • China
  • variation and trend characteristics
  • multiple observation
  • coordinated control of PM and ozone

Published Papers (9 papers)

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Research

13 pages, 3875 KiB  
Article
Characteristics and Meteorological Effects of Ozone Pollution in Spring Season at Coastal City, Southeast China
by Saisai Ren, Xiaoting Ji, Xiangliang Zhang, Meimei Huang, Hong Li and Hong Wang
Atmosphere 2022, 13(12), 2000; https://doi.org/10.3390/atmos13122000 - 29 Nov 2022
Cited by 2 | Viewed by 1080
Abstract
Surface ozone (O3) pollution has become one of the top environmental issues in recent years around the world and can be influenced by meteorological processes on multiple scales. Understanding the meteorological mechanism and contributions of O3 pollution is of great [...] Read more.
Surface ozone (O3) pollution has become one of the top environmental issues in recent years around the world and can be influenced by meteorological processes on multiple scales. Understanding the meteorological mechanism and contributions of O3 pollution is of great importance for O3 mitigation. In this study, we explored the impacts of meteorological conditions on O3 concentrations in a coastal city in Southeast China, with a particular focus on O3 pollution episodes inspringtime. A significant increase in the O3 pollution ratefrom 2015 to 2020 was observed (41.7% year−1) and the seasonal characteristics of O3 concentrations showed a two-peak pattern. We selected 12 pollution episodes during the springtime of 2015 to 2020 and identified four dominant synoptic weather patterns (SWPs) that could cause O3 pollution. The local meteorological conditions and vertical dynamic structures under different SWPs were analyzed. The results showed that high O3 levels tend to be associated with high temperature, weak wind, low relative humidity, and deep vertical sinking motion. We also established a quantitative linkage between the O3 values and meteorological factors. Based on meteorological conditions, 60.8~80.8% of the variation in O3 can be explained. Full article
(This article belongs to the Special Issue Remote Sensing and Multiple Observations of Air Quality in China)
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16 pages, 10238 KiB  
Article
Research on Lidar Network Observation of Aerosol and Pollution in Beijing 2022 Winter Olympics
by Tong Lu, Zhigang Li, Yubao Chen, Zhichao Bu and Xiaopeng Wang
Atmosphere 2022, 13(11), 1901; https://doi.org/10.3390/atmos13111901 - 14 Nov 2022
Cited by 1 | Viewed by 1198
Abstract
During the Beijing Winter Olympics, three sets of aerosol lidar in different regions were used to conduct continuous observations to study the optical properties and vertical distribution characteristics of atmospheric aerosol. Based on the lidar data and sun photometer data, the accurate lidar [...] Read more.
During the Beijing Winter Olympics, three sets of aerosol lidar in different regions were used to conduct continuous observations to study the optical properties and vertical distribution characteristics of atmospheric aerosol. Based on the lidar data and sun photometer data, the accurate lidar ratio was determined to improve the inversion accuracy of the aerosol backscattering coefficient. The influence of meteorological conditions such as temperature, relative humidity, wind speed, and wind direction on the optical properties of aerosol were analyzed, and the type of aerosol was classified by the depolarization ratio of aerosol particles and CALIPSO data. Furthermore, the backward trajectory analysis, potential source contribution function (PSCF), and concentration weighted trajectories (CWT) were employed to explore the sources and transport mechanisms of pollutants. The analysis found that the extinction coefficient under the atmospheric boundary layer during the Winter Olympics had a spatial distribution pattern of high value in the southeast and low value in the northwest. The occurrence of aerosol pollution events is not only caused by local emissions, but is also related to regional transmission. Full article
(This article belongs to the Special Issue Remote Sensing and Multiple Observations of Air Quality in China)
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16 pages, 4293 KiB  
Article
The Temporal–Spatial Characteristics of Column NO2 Concentration and Influence Factors in Xinjiang of Northwestern Arid Region in China
by Zhixiang Yu and Xia Li
Atmosphere 2022, 13(10), 1533; https://doi.org/10.3390/atmos13101533 - 20 Sep 2022
Viewed by 1296
Abstract
This paper investigates the temporal–spatial characteristics of column NO2 concentration and influence factors in Xinjiang based on the Tropospheric Monitoring Instrument (TROPOMI) aboard the EU/ESA Sentinel-5 Precursor satellite. The findings indicate that there is a high linear correlation between TROPOMI NO2 [...] Read more.
This paper investigates the temporal–spatial characteristics of column NO2 concentration and influence factors in Xinjiang based on the Tropospheric Monitoring Instrument (TROPOMI) aboard the EU/ESA Sentinel-5 Precursor satellite. The findings indicate that there is a high linear correlation between TROPOMI NO2 data and ground-based data, with Yining having the highest correlation (R2 = 0.8132) and Aksu having the lowest correlation (R2 = 0.7307). The TROPOMI NO2 data can be used to approximate the characteristics of near-surface atmospheric NO2 concentration. NO2 VCD in the troposphere varies greatly geographically, with a noticeable ‘island’ pattern. The high-value zones are mostly found on the northern slope of Tianshan Mountain, in the capital cities of several prefectures, and occasionally in the industrial parks. Urumqi has the highest annual average NO2 VCD of 553.9 × 10−6 mol·m−2. The NO2 VCD is characterized by seasonal shifts and cyclical swings of “low in spring, high in winter, and transition in summer and autumn”. The monthly mean value is highest in December (27.14 × 10−6 mol m−2) and lowest in March (12.66 × 10−6 mol m−2). Meteorological factors can influence the temporal and spatial distribution of NO2 VCD. The GRA in Urumqi is 0.774 between the monthly mean of NO2 VCD and relative humidity. The main causes of the increase in NO2 VCD are man-made emissions. The annual GDP of the secondary industry and its annual average NO2 VCD in fifteen key cities in Xinjiang have a correlation coefficient of 0.78. TROPOMI NO2 data can provide strong support for the fine control of air pollution and air quality in early warning forecast in Xinjiang. Full article
(This article belongs to the Special Issue Remote Sensing and Multiple Observations of Air Quality in China)
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14 pages, 4902 KiB  
Article
Analysis of Ozone Vertical Profiles over Wuyishan Region during Spring 2022 and Their Correlations with Meteorological Factors
by Tianfu Zhu, Huiying Deng, Jinhong Huang, Yulan Zheng, Ziliang Li, Rui Zhao and Hong Wang
Atmosphere 2022, 13(9), 1505; https://doi.org/10.3390/atmos13091505 - 15 Sep 2022
Viewed by 1446
Abstract
Understanding the vertical structure of ozone concentrations in different seasons and their correlations with the associated meteorological conditions is crucial for exploring atmospheric ozone variability and improving the accuracy of regional ozone prediction. In this study, an ozone-sounding experiment was carried out at [...] Read more.
Understanding the vertical structure of ozone concentrations in different seasons and their correlations with the associated meteorological conditions is crucial for exploring atmospheric ozone variability and improving the accuracy of regional ozone prediction. In this study, an ozone-sounding experiment was carried out at the Shaowu sounding Station in Fujian from November 2021 to May 2022 in order to obtain vertical profiles of ozone concentrations and synoptic variables. Based on these observations, we examined the characteristics of tropospheric ozone profiles in spring over the Wuyishan region and their comparison with wintertime ozone. The results show that compared with winter, the total ozone column (TOC) in spring has increased by 64.4%, with an enhancement of 23.8% for the troposphere and a greater increment of 69.1% for the stratosphere. The sub-peaks of tropospheric ozone below 12 km are found in both spring and winter of 2022, which are accompanied by lower relative humidity (<10% in winter and <15% in spring), temperature inversions in some cases, and intensive westerly winds. Furthermore, we investigated the relationship between ozone volume mixing ratio (OVMR) and synoptic conditions in the Wuyishan region and concluded that OVMR above 1.5 km is negatively correlated with temperature and relative humidity but positively correlated with wind speed. Additionally, springtime OVMR in the middle and upper troposphere exhibits a “funnel” distribution, showing a higher OVMR on the day of sounding observations and one day before and after that on adjacent days with low-level southwesterly winds and updrafts. While in winter, the strong downdrafts dominate on the sounding observation day. Full article
(This article belongs to the Special Issue Remote Sensing and Multiple Observations of Air Quality in China)
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12 pages, 7169 KiB  
Article
Temporal Variation and Source Analysis of Atmospheric CH4 at Different Altitudes in the Background Area of Yangtze River Delta
by Meng Shan, Honghui Xu, Lujie Han, Yuting Pang, Juncheng Ma and Chao Zhang
Atmosphere 2022, 13(8), 1206; https://doi.org/10.3390/atmos13081206 - 31 Jul 2022
Cited by 1 | Viewed by 1292
Abstract
Through an analysis of CH4 data observed at different altitudes at the atmospheric background station in Lin’an from 2016 to 2020, in combination with back-trajectory and distribution characteristics of potential source areas, the CH4 concentration variations at higher and lower altitudes [...] Read more.
Through an analysis of CH4 data observed at different altitudes at the atmospheric background station in Lin’an from 2016 to 2020, in combination with back-trajectory and distribution characteristics of potential source areas, the CH4 concentration variations at higher and lower altitudes and their relationships with sources and sinks were studied. The results showed that the CH4 concentration was characterized by notable diurnal variations. The largest concentration difference occurred between 5 and 7 a.m.; the concentration difference in summer was higher than that in the other three seasons. Background filtering of the hourly CH4 concentration was carried out using a numerical method. The results showed that the difference in the CH4 background concentration between the two altitudes was 4.6 ppb (SD = 7.9). The CH4 background concentrations at the two altitudes had the same seasonal variation: double peaks and valleys. The peaks appeared in May and December, and the valleys appeared in March and July. In spring and summer, the potential CH4 source areas were mainly distributed in the rice planting and wetland discharge regions. In autumn, they were mainly distributed in regions affected by fugitive emissions from rice planting and coal mining. In winter, they were mainly distributed in livestock and poultry management regions. Full article
(This article belongs to the Special Issue Remote Sensing and Multiple Observations of Air Quality in China)
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11 pages, 1907 KiB  
Article
A Study of the Vertical Distribution and Sub-Peaks of Ozone below 12 km over Wuyishan Region Based on Ozone Sounding in Winter
by Yulan Zheng, Huiying Deng, Huabiao You, Yiming Qiu, Tianfu Zhu, Xugeng Cheng and Hong Wang
Atmosphere 2022, 13(6), 979; https://doi.org/10.3390/atmos13060979 - 17 Jun 2022
Cited by 1 | Viewed by 1595
Abstract
An understanding of the vertical distribution of ozone is critical to assessing the ozone variabilities both in the stratosphere and the troposphere. We collected the profiles of atmospheric ozone partial pressure and ozone volume mixing ratio (VMR) by a sounding system at the [...] Read more.
An understanding of the vertical distribution of ozone is critical to assessing the ozone variabilities both in the stratosphere and the troposphere. We collected the profiles of atmospheric ozone partial pressure and ozone volume mixing ratio (VMR) by a sounding system at the Wuyi Mountain National Meteorological Observation Station (Shaowu sounding station 58725) from November 2021 to February 2022. In this study, the vertical distribution and sub-peak phenomenon of tropospheric ozone below 12 km are investigated using mathematical statistics and synthetic analysis. The results show that the ozone partial pressure decreased from the ground to the tropopause, which is consistent with the temperature profile. However, 66.7% of cases first showed an increasing trend from the ground to about 3 km, while there were one or more temperature inversions in the corresponding temperature profiles and the atmosphere was stable and the relative humidity was high; then, in the stratosphere, the ozone partial pressure began to increase significantly, The ozone partial pressure reaches its maximum at an average height of 24.9 km, and the maximum value was 14 mPa. The ozone VMR in troposphere is the fluctuating increase from the ground to the tropopause, and 83.3% of the cases begin to rise rapidly at about 2–5 km away from the tropopause, and the ozone surge height is 2.9 km lower than the tropopause on average. Some of these tropopause ozone VMR have shown the characteristics of stratospheric ozone. The sub-peaks of tropospheric ozone below 12 km has four cases. All the sub-peaks occur between 6.7 km and 11.5 km vertically, and peak ozone VMR is 1.6–1.9 times larger than that of the average state at the same height. The maximum stratospheric ozone VMR is 8649 ppb on average, occurring at an average height of 31.3 km, and this average height of the maximum stratospheric ozone VMR is 6.4 km higher than that for the ozone partial pressure. The total ozone in the boundary layer (0–1.5 km) is 4.3 DU on average, accounting for 1.5% in total ozone column. The total ozone in the troposphere is 39.5 DU, accounting for 13.1% in total ozone column, and the total ozone in the stratosphere is 262.4 DU, accounting for 86.9% in total ozone column. Full article
(This article belongs to the Special Issue Remote Sensing and Multiple Observations of Air Quality in China)
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15 pages, 2213 KiB  
Article
Temporal Variation of NO2 and HCHO Vertical Profiles Derived from MAX-DOAS Observation in Summer at a Rural Site of the North China Plain and Ozone Production in Relation to HCHO/NO2 Ratio
by Siyang Cheng, Junli Jin, Jianzhong Ma, Jinguang Lv, Shuyin Liu and Xiaobin Xu
Atmosphere 2022, 13(6), 860; https://doi.org/10.3390/atmos13060860 - 25 May 2022
Cited by 4 | Viewed by 2070
Abstract
We performed a comprehensive and intensive field experiment including ground-based multi-axis differential optical absorption spectroscopy (MAX-DOAS) measurement at Raoyang (115°44′ E, 38°14′ N; 20 m altitude) in summer (13 June–20 August) 2014. The NO2 and HCHO profiles retrieved by MAX-DOAS take on [...] Read more.
We performed a comprehensive and intensive field experiment including ground-based multi-axis differential optical absorption spectroscopy (MAX-DOAS) measurement at Raoyang (115°44′ E, 38°14′ N; 20 m altitude) in summer (13 June–20 August) 2014. The NO2 and HCHO profiles retrieved by MAX-DOAS take on different vertical distribution shapes, with the former declining with the increasing altitude and the latter having an elevated layer. The average levels of vertical column densities (VCDs) and near-surface volume mixing ratios (VMRs) were 1.02 ± 0.51 × 1016 molec·cm−2 and 3.23 ± 2.70 ppb for NO2 and 2.32 ± 0.56 × 1016 molec·cm−2 and 5.62 ± 2.11 ppb for HCHO, respectively. The NO2 and HCHO levels are closely connected with meteorological conditions, with the larger NO2 VCDs being associated with lower temperature, higher relative humidity (RH) and lower planetary boundary layer height (PBLH). With respect to the diurnal variations of vertical distribution, the NO2 in the residual layer gradually disappeared from 1.2 km height to the surface during the period of 7:00–11:00 Beijing time (BJ), and the near-surface NO2 had larger VMRs in the early morning and evening than in the later morning and afternoon. An elevated HCHO layer was observed to occur persistently with the lifted layer height rising from ~0.5 km to ~1.0 km before 10:00 BJ; the near-surface HCHO VMRs gradually increased and peaked around 10:00 BJ. The ratios of HCHO to NO2 (RHCHO-NO2) were generally larger than two in the boundary layer from 11:00 BJ until 19:00 BJ, the time period when ozone photochemistry was most active. Thus, ozone (O3) production was mainly in the NOx-limited regime during the observation campaign, which was closely related to relatively high temperatures and low RH. The O3 production regimes also changed with the wind’s direction. These results are significant to reveal the formation mechanism of O3 pollution and develop strategies for controlling the O3 photochemical pollution over the North China Plain. Full article
(This article belongs to the Special Issue Remote Sensing and Multiple Observations of Air Quality in China)
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13 pages, 2719 KiB  
Article
Chemical Composition Characteristics and Source Contributions of Precipitation in Typical Cities on the North Slope of Tianshan Mountain in Xinjiang during 2010–2019
by Yuting Zhong, Xia Li, Ziang Fan, Maulen Ayitken, Shuting Li and Xinchun Liu
Atmosphere 2022, 13(5), 646; https://doi.org/10.3390/atmos13050646 - 20 Apr 2022
Cited by 5 | Viewed by 1721
Abstract
This work presents the results of a ten-year investigation (2010–2019) on the characteristics and sources of precipitation pollution in typical cities locating in the economic belt on the North Slope of Tianshan Mountain, Xinjiang. The water-soluble ions’ characteristics (Na+, NH4 [...] Read more.
This work presents the results of a ten-year investigation (2010–2019) on the characteristics and sources of precipitation pollution in typical cities locating in the economic belt on the North Slope of Tianshan Mountain, Xinjiang. The water-soluble ions’ characteristics (Na+, NH4+, K+, Mg2+, Ca2+, F−, Cl−, SO42−, NO3−), neutralizing capacity, wet deposition and sources of precipitation in Urumqi, Karamay and Yining during 2010–2019 were compared and analyzed. The study showed that from 2010 to 2019, the pH value of precipitation in Urumqi, Karamay and Yining varied from 4.18 to 10.55 with a volume-weighted mean (VWM) pH of 6.33, and the pH value showed an upward trend overall. The VWM electrical conductivity (EC) of the precipitation was the highest in Urumqi and the lowest in Yining, indicating that Urumqi was the most polluted and Yining was relatively clean. The most important cation in the precipitation of the three cities was Ca2+, and the most important anion was SO42−. The ratio of SO42−/NO3− indicated that the air pollution in Urumqi and Yining belonged to the typical coal-smoke air pollution, while there was compound pollution in Karamay. As can be seen from the neutralization factor, Ca2+ had the strongest neutralization ability, followed by Na+ and NH4+. Nitrate and sulfate in the atmosphere of Urumqi, Karamay and Yining are likely to exist in the form of NH4NO3, CaSO4 and (NH4)2SO4•CaSO4•2H2O. Wet deposition flux analysis of S and N showed that S pollution of the precipitation in Urumqi showed a decreasing trend, while N pollution showed an increasing trend. S pollution of the precipitation in Karamay gradually decreased, while N pollution of the precipitation in Yining became more and more serious. By analyzing origins of major ions in precipitation, it is concluded that human activities (industry, agriculture, heating, and transportation) are the main sources of ions in precipitation, and natural sources (soil dust) also play an important role. Full article
(This article belongs to the Special Issue Remote Sensing and Multiple Observations of Air Quality in China)
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18 pages, 9372 KiB  
Article
Characterization of VOCs during Nonheating and Heating Periods in the Typical Suburban Area of Beijing, China: Sources and Health Assessment
by Bi’an Zhou, Tianyi Zhao, Jian Ma, Yuanxun Zhang, Lijia Zhang, Peng Huo and Yang Zhang
Atmosphere 2022, 13(4), 560; https://doi.org/10.3390/atmos13040560 - 30 Mar 2022
Cited by 4 | Viewed by 2058
Abstract
In recent years, the “coal to electricity” project (CTEP) using clean energy instead of coal for heating has been implemented by Beijing government to cope with air pollution. However, VOC pollution after CTEP was rarely studied in suburbs of Beijing. To fill this [...] Read more.
In recent years, the “coal to electricity” project (CTEP) using clean energy instead of coal for heating has been implemented by Beijing government to cope with air pollution. However, VOC pollution after CTEP was rarely studied in suburbs of Beijing. To fill this exigency, 116 volatile organic compounds (VOCs) were observed during nonheating (P1) and heating (P2) periods in suburban Beijing. The results showed that the total of VOCs (TVOCs) was positively correlated with PM2.5, PM10, NO2, CO, and SO2 but negatively correlated with O3 and wind speed. The average TVOCs concentration was 19.43 ± 12.41 ppbv in P1 and 16.25 ± 8.01 ppbv in P2. Aromatics and oxygenated VOCs (OVOCs) were the main contributors to ozone formation potential (OFP). Seven sources of VOCs identified by the positive matrix factorization (PMF) model were industrial source, coal combustion, fuel evaporation, gasoline vehicle exhaust, diesel vehicle exhaust, background and biogenic sources, and solvent usage. The contribution of coal combustion to VOCs increased significantly during P2, whereas industrial sources, fuel evaporation, and solvent usage exhibited opposite trends. The potential source contribution function (PSCF) and concentration weighted trajectory (CWT) were used to analyze the source distributions. The results showed that VOC pollution was caused mainly by air mass from southern Hebei during P1 but by local emissions during P2. Therefore, although the contribution of coal combustion after heating increased, TVOCs concentration during P2 was lower than that during P1. Chronic noncarcinogenic risks of all selected VOC species were below the safe level, while the carcinogenic risks of most selected VOC species were above the acceptable risk level, especially for tetrachloromethane and 1,2-dichloroethane. The cancer risks posed by gasoline vehicle emissions, industrial enterprises, and coal combustion should be paid more attention. Full article
(This article belongs to the Special Issue Remote Sensing and Multiple Observations of Air Quality in China)
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