scholarly journals Impacts of Meteorological Factors, VOCs Emissions and Inter-Regional Transport on Summer Ozone Pollution in Yuncheng

Atmosphere ◽  
2021 ◽  
Vol 12 (12) ◽  
pp. 1661
Author(s):  
Chenyue Zhang ◽  
Shuzhen Luo ◽  
Wenting Zhao ◽  
Yuntao Wang ◽  
Qiang Zhang ◽  
...  
Keyword(s):  
Long Range ◽  
Meteorological Factors ◽  
Surface Ozone ◽  
Ratio Method ◽  
Long Range Transport ◽  
Characteristic Ratio ◽  
Near Surface ◽  
Potential Source ◽  
Hourly Data ◽  
Range Transport

Summer ozone (O3) pollution in China has become increasingly serious in recent years. This study is based on hourly data of near-surface ozone (O3) and nitrogen oxides (NOx) and volatile organic compounds (VOCs) from June to August 2020 in Yuncheng, combined with meteorological data to analyse the characteristics of O3 pollution in summer and the influence of meteorological factors, precursors, and long-range transport on O3 pollution. In this paper, the VOCs/NOx characteristic ratio method was used to explore the sensitivity of O3 generation. Backward trajectories, cluster analysis, potential source contribution factor (PSCF) analysis and concentration weight trajectory (CWT) analysis were also calculated using Trajstat software. In 2020, Yuncheng had persistent O3 pollution, with the highest concentrations in June, significantly higher than July and August. Conditions of high temperature, low relative humidity and low wind speed contribute to the O3 accumulation. VOCs are the main precursors to the local production of O3. Besides, the long-range transport analysis shows that southeast-oriented air masses are the main direction influencing summer O3 pollution. The primary potential source areas of O3 are in the central and southern part of Henan province, the north-western Anhui province, and the northern Shaanxi. In addition, northern Hubei and southwestern Shandong also influence O3 pollution in summer Yuncheng.

scholarly journals Multi-scale modeling study of the source contributions to near-surface ozone and sulfur oxides levels over California during the ARCTAS-CARB period

2010 ◽  
Vol 10 (11) ◽  
pp. 27777-27823 ◽  
Author(s):  
M. Huang ◽  
G. R. Carmichael ◽  
S. N. Spak ◽  
B. Adhikary ◽  
S. Kulkarni ◽  
...  
Keyword(s):  
Long Range ◽  
Surface Ozone ◽  
Long Range Transport ◽  
Sulfur Oxides ◽  
Study Region ◽  
Near Surface ◽  
Fire Emissions ◽  
Multi Scale ◽  
Range Transport ◽  
Local Emissions

Abstract. Chronic ozone (O3) problems and the increasing sulfur oxides (SOx=SO2+SO4) ambient concentrations over South Coast (SC) and other areas of California (CA) are affected by both local emissions and long-range transport. In this paper, multi-scale tracer and full-chemistry simulations with the STEM atmospheric chemistry model are used to assess the contribution of local emission sources to SC O3 and evaluate the impacts of transported sulfur and local emissions on the SC sulfur budget during the ARCTAS-CARB experiment period in 2008. Sensitivity simulations quantify contributions of biogenic and fire emissions to SC O3 levels. California biogenic and fire emissions contribute 3–4 ppb to near-surface O3 over SC, with larger contributions to other regions in CA. Long-range transport from Asia is estimated to enhance surface SO4 over SC by ~0.5 μg/sm3, and the higher SOx levels (up to ~0.7 ppb of SO2 and ~6 μg/sm3 of SO4) observed above ~6 km did not affect surface air quality in the study region. Enhanced near-surface SOx levels over SC during the flight week were attributed mostly to local emissions. Two anthropogenic SOx emission inventories (EIs) from the California Air Resources Board (CARB) and the US Environmental Protection Agency (EPA) are compared and applied in 60 km and 12 km chemical transport simulations, and the results are compared with observations. The CARB EI shows improvements over the National Emission Inventory (NEI) by EPA, but generally underestimates surface SC SOx by about a factor of two. Maritime (mostly shipping) emissions contribute to the high SO2 levels over the ocean and on-shore, and fine SO4 over the downwind areas is impacted by maritime sources. Maritime emissions also modify the NOx-VOC limitations over coastal areas. These suggest an important role for shipping emission controls in reducing fine particle and O3 concentrations in SC.

scholarly journals Multi-scale modeling study of the source contributions to near-surface ozone and sulfur oxides levels over California during the ARCTAS-CARB period

2011 ◽  
Vol 11 (7) ◽  
pp. 3173-3194 ◽  
Author(s):  
M. Huang ◽  
G. R. Carmichael ◽  
S. N. Spak ◽  
B. Adhikary ◽  
S. Kulkarni ◽  
...  
Keyword(s):  
Long Range ◽  
Atmospheric Chemistry ◽  
Surface Ozone ◽  
Long Range Transport ◽  
Sulfur Oxides ◽  
Near Surface ◽  
Fire Emissions ◽  
Multi Scale ◽  
Range Transport ◽  
Local Emissions

Abstract. Chronic high surface ozone (O3) levels and the increasing sulfur oxides (SOx = SO2+SO4) ambient concentrations over South Coast (SC) and other areas of California (CA) are affected by both local emissions and long-range transport. In this paper, multi-scale tracer, full-chemistry and adjoint simulations using the STEM atmospheric chemistry model are conducted to assess the contribution of local emission sourcesto SC O3 and to evaluate the impacts of transported sulfur and local emissions on the SC sulfur budgetduring the ARCTAS-CARB experiment period in 2008. Sensitivity simulations quantify contributions of biogenic and fire emissions to SC O3 levels. California biogenic and fire emissions contribute 3–4 ppb to near-surface O3 over SC, with larger contributions to other regions in CA. During a long-range transport event from Asia starting from 22 June, high SOx levels (up to ~0.7 ppb of SO2 and ~1.3 ppb of SO4) is observed above ~6 km, but they did not affect CA surface air quality. The elevated SOx observed at 1–4 km is estimated to enhance surface SOx over SC by ~0.25 ppb (upper limit) on ~24 June. The near-surface SOx levels over SC during the flight week are attributed mostly to local emissions. Two anthropogenic SOx emission inventories (EIs) from the California Air Resources Board (CARB) and the US Environmental Protection Agency (EPA) are compared and applied in 60 km and 12 km chemical transport simulations, and the results are compared withobservations. The CARB EI shows improvements over the National Emission Inventory (NEI) by EPA, but generally underestimates surface SC SOx by about a factor of two. Adjoint sensitivity analysis indicated that SO2 levels at 00:00 UTC (17:00 local time) at six SC surface sites were influenced by previous day maritime emissions over the ocean, the terrestrial emissions over nearby urban areas, and by transported SO2 from the north through both terrestrial and maritime areas. Overall maritime emissions contribute 10–70% of SO2 and 20–60% fine SO4 on-shore and over the most terrestrial areas, with contributions decreasing with in-land distance from the coast. Maritime emissions also modify the photochemical environment, shifting O3 production over coastal SC to more VOC-limited conditions. These suggest an important role for shipping emission controls in reducing fine particle and O3 concentrations in SC.

scholarly journals Elevated Ozone Layers over the Seoul Metropolitan Region in Korea: Evidence for Long-Range Ozone Transport from Eastern China and Its Contribution to Surface Concentrations

2010 ◽  
Vol 49 (2) ◽  
pp. 203-220 ◽  
Author(s):  
In-Bo Oh ◽  
Yoo-Keun Kim ◽  
Mi-Kyung Hwang ◽  
Cheol-Hee Kim ◽  
Soontae Kim ◽  
...  
Keyword(s):  
Long Range ◽  
Transport Process ◽  
Surface Ozone ◽  
Eastern China ◽  
Metropolitan Region ◽  
Long Range Transport ◽  
Pressure System ◽  
Elevated Ozone ◽  
Range Transport ◽  
Seoul Metropolitan Region

Abstract Elevated layers of high ozone concentration were observed over the Seoul metropolitan region (SMR) in Korea by ozonesonde measurements during 6–9 June 2003. An analysis of the synoptic-scale meteorological features and backward trajectories revealed that the layers were associated with the long-range transport of ozone from eastern China. Further examination of the long-range transport process responsible for the development of these layers was performed using the Community Multiscale Air Quality (CMAQ) model. CMAQ demonstrated that the upward mixing of ozone by convective activity in eastern China and subsequent horizontal transport aloft in the periphery of a slow-moving high pressure system led to the development of thick ozone layers over the SMR. Through comparative simulation studies, it was found that the surface ozone levels in the SMR can be significantly enhanced by the vertical down-mixing of ozone from the layer aloft with the growing mixed layer. On average, about 25% of the surface peak concentration in a given area during a high-ozone episode was due to the influence of the ozone layer aloft developed by the long-range transport process.

scholarly journals Vertical distribution of aerosol optical properties in the Po Valley during the 2012 summer campaigns

2018 ◽  
Vol 18 (8) ◽  
pp. 5371-5389 ◽  
Author(s):  
Silvia Bucci ◽  
Paolo Cristofanelli ◽  
Stefano Decesari ◽  
Angela Marinoni ◽  
Silvia Sandrini ◽  
...  
Keyword(s):  
Vertical Distribution ◽  
Long Range ◽  
Mineral Dust ◽  
Dust Particles ◽  
Long Range Transport ◽  
Hygroscopic Growth ◽  
Limit Values ◽  
Near Surface ◽  
Po Valley ◽  
Range Transport

Abstract. Studying the vertical distribution of aerosol particle physical and chemical properties in the troposphere is essential to understand the relative importance of local emission processes vs. long-range transport for column-integrated aerosol properties (e.g. the aerosol optical depth, AOD, affecting regional climate) as well as for the aerosol burden and its impacts on air quality at the ground. The main objective of this paper is to investigate the transport of desert dust in the middle troposphere and its intrusion into the planetary boundary layer (PBL) over the Po Valley (Italy), a region considered one of the greatest European pollution hotspots for the frequency that particulate matter (PM) limit values are exceeded. Events of mineral aerosol uplift from local (soil) sources and phenomena of hygroscopic growth at the ground are also investigated, possibly affecting the PM concentration in the region as well. During the PEGASOS 2012 field campaign, an integrated observing–modelling system was set up based on near-surface measurements (particle concentration and chemistry), vertical profiling (backscatter coefficient profiles from lidar and radiosoundings) and Lagrangian air mass transport simulations by FLEXPART model. Measurements were taken at the San Pietro Capofiume supersite (44°39′ N, 11°37′ E; 11 m a.s.l.), located in a rural area relatively close to some major urban and industrial emissive areas in the Po Valley. Mt. Cimone (44°12′ N, 10°42′ E; 2165 m a.s.l.) WMO/GAW station observations are also included in the study to characterize regional-scale variability. Results show that, in the Po Valley, aerosol is detected mainly below 2000 m a.s.l. with a prevalent occurrence of non-depolarizing particles ( > 50 % throughout the campaign) and a vertical distribution modulated by the PBL daily evolution. Two intense events of mineral dust transport from northern Africa (19–21 and 29 June to 2 July) are observed, with layers advected mainly above 2000 m, but subsequently sinking and mixing in the PBL. As a consequence, a non-negligible occurrence of mineral dust is observed close to the ground ( ∼ 7 % of occurrence during a 1-month campaign). The observations unambiguously show Saharan dust layers intruding the Po Valley mixing layer and directly affecting the aerosol concentrations near the surface. Finally, lidar observations also indicate strong variability in aerosol on shorter timescales (hourly). Firstly, these highlight events of hygroscopic growth of anthropogenic aerosol, visible as shallow layers of low depolarization near the ground. Such events are identified during early morning hours at high relative humidity (RH) conditions (RH  > 80 %). The process is observed concurrently with high PM1 nitrate concentration (up to 15 µg cm−3) and hence mainly explicable by deliquescence of fine anthropogenic particles, and during mineral dust intrusion episodes, when water condensation on dust particles could instead represent the dominant contribution. Secondly, lidar images show frequent events (mean daily occurrence of  ∼  22 % during the whole campaign) of rapid uplift of mineral depolarizing particles in afternoon–evening hours up to 2000 m a.s.l. height. The origin of such particles cannot be directly related to long-range transport events, being instead likely linked to processes of soil particle resuspension from agricultural lands.

scholarly journals Forecasting the North African dust outbreak towards Europe in April 2011: a model intercomparison

2015 ◽  
Vol 15 (19) ◽  
pp. 26661-26710 ◽  
Author(s):  
N. Huneeus ◽  
S. Basart ◽  
S. Fiedler ◽  
J.-J. Morcrette ◽  
A. Benedetti ◽  
...  
Keyword(s):  
Long Range ◽  
Assessment System ◽  
Horizontal Wind ◽  
Northern Europe ◽  
Long Range Transport ◽  
Lead Times ◽  
Near Surface ◽  
Synoptic Conditions ◽  
Range Transport ◽  
Scavenging Efficiency

Abstract. In the framework of the World Meteorological Organisation's Sand and Dust Storm Warning Advisory and Assessment System, we evaluated the predictions of five state-of-the-art dust forecast models during an intense Saharan dust outbreak affecting Western and Northern Europe in April 2011. We assessed the capacity of the models to predict the evolution of the dust cloud with lead-times of up to 72 h using observations of aerosol optical depth (AOD) from the Aerosol Robotic Network (AERONET) and the Moderate Resolution Imaging Spectroradiometer (MODIS), and dust surface concentrations from a ground-based measurement network. In addition, the predicted vertical dust distribution was evaluated with vertical extinction profiles from the Cloud and Aerosol Lidar with Orthogonal Polarization (CALIOP). To assess the diversity in forecast capability among the models, the analysis was extended to wind field (both surface and profile), synoptic conditions, emissions and deposition fluxes. Models predict the onset and evolution of the AOD for all analysed lead-times. On average, differences among the models are larger than differences among lead-times for each individual model. In spite of large differences in emission and deposition, the models present comparable skill for AOD. In general, models are better in predicting AOD than near-surface dust concentration over the Iberian Peninsula. Models tend to underestimate the long-range transport towards Northern Europe. Our analysis suggests that this is partly due to difficulties in simulating the vertical distribution dust and horizontal wind. Differences in the size distribution and wet scavenging efficiency may also account for model diversity in long-range transport.

scholarly journals Scattering and absorption properties of near-surface aerosol over Gangetic–Himalayan region: the role of boundary layer dynamics and long-range transport

2014 ◽  
Vol 14 (15) ◽  
pp. 21101-21148 ◽  
Author(s):  
U. C. Dumka ◽  
D. G. Kaskaoutis ◽  
M. K. Srivastava ◽  
P. C. S. Devara
Keyword(s):  
Boundary Layer ◽  
Long Range ◽  
Long Range Transport ◽  
Monsoon Circulation ◽  
Anthropogenic Aerosols ◽  
Absorption Properties ◽  
Near Surface ◽  
Range Transport ◽  
Boundary Layer Dynamics

Abstract. Knowledge of light scattering and absorption properties of atmospheric aerosols is of vital importance in evaluating their types, sources and radiative forcing. This is of particular interest over the Gangetic–Himalayan (GH) region due to large aerosol loading over the plains and the uplift over the Himalayan range causing serious effects on atmospheric heating, glaciology and monsoon circulation. In this respect, Ganges Valley Aerosol Experiment (GVAX) was initiated over the region aiming to examine the aerosol properties, source regions, uplift mechanisms and aerosol-cloud interactions. The present study examines the temporal (monthly, seasonal) evolution of scattering (σsp) and absorption (σap) coefficients, their wavelength dependence, and the role of the Indo-Gangetic plains (IGP), boundary-layer dynamics (BLD) and long-range transport (LRT) in the aerosol uplift over the Himalayas. The measurements are performed at the elevated site Nainital via the Atmospheric Radiation Measurement Mobile Facility including several instruments (Nephelometer, Particle Soot Absorption Photometer, etc.) during June 2011 to March 2012. The σsp and σap exhibit a pronounced seasonal variation with monsoon low and post-monsoon (November) high, while the scattering wavelength exponent exhibits higher values during monsoon, in contrast to the absorption Ångström exponent which maximizes in December–March. The analysis is performed separately for particles bellow 10 and 1μm in diameter in order to examine the influence of the particle size on optical properties. The elevated-background measuring site provides the advantage of examining the LRT of natural and anthropogenic aerosols from the IGP and southwest Asia and the role of BLD in the aerosol lifting processes, while the aerosols are found to be well-mixed and aged-type dominant.

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