scholarly journals Regional evaluation of the performance of the global CAMS chemical modeling system over the United States (IFS cycle 47r1)

2021 ◽  
Author(s):  
Jason Edward Williams ◽  
Vincent Huijnen ◽  
Idir Bouarar ◽  
Mehdi Meziane ◽  
Timo Schreurs ◽  
...  
Keyword(s):  
United States ◽  
Air Quality ◽  
Data Assimilation ◽  
Atmospheric Chemistry ◽  
The United States ◽  
Trace Gas ◽  
Chemically Induced ◽  
Quality Aspects ◽  
Tropospheric O3 ◽  
Aerosol Modeling

Abstract. The Copernicus Atmosphere Monitoring Service (CAMS) provides routine analyses and forecasts of trace gases and aerosols on a global scale. The core is ECMWF’s Integrated Forecast System (IFS), where modules for atmospheric chemistry and aerosols have been introduced, and which allows data-assimilation of satellite retrievals of composition. We have updated both the homogeneous and heterogeneous NOx chemistry applied in the three independent tropospheric-stratospheric chemistry modules maintained within CAMS, referred to as IFS(CB05BASCOE), IFS(MOCAGE) and IFS(MOZART). Here we focus on the evaluation of main trace gas products from these modules that are of interest as markers of air quality, namely lower tropospheric O3, NO2 and CO, with a regional focus over the contiguous United States without data assimilation. Evaluation against lower tropospheric composition reveals overall good performance, with chemically induced biases within 10 ppb across species across regions within the US with respect to a range of observations. The versions show overall equal or better performance than the CAMS Reanalysis. Evaluation of surface air quality aspects shows that annual cycles are captured well, albeit with variable seasonal biases. During wintertime conditions there is a large model spread between chemistry schemes in lower-tropospheric O3 (~10–35 %) and, in turn, oxidative capacity related to NOx lifetime differences. Analysis of differences in the HNO3 and PAN formation, which act as reservoirs for reactive nitrogen, revealed a general underestimate in PAN formation over polluted regions likely due to too low organic precursors. Particularly during wintertime, the fraction of NO2 sequestered into PAN has a variability of 100 % across chemistry modules indicating the need for further constraints. Notably a considerable uncertainty in HNO3 formation associated with wintertime N2O5 conversion on wet particle surfaces remains. In summary this study has indicated that the chemically induced differences in the quality of CAMS forecast products over the United States depends on season, trace gas, altitude and region. Whilst analysis of the three chemistry modules in CAMS provide a strong handle on uncertainties associated with chemistry modeling, the further improvement of operational products additionally requires coordinated development involving emissions handling, chemistry and aerosol modeling, complemented with data-assimilation efforts.

scholarly journals The contribution of marine organics to the air quality of the western United States

2010 ◽  
Vol 10 (15) ◽  
pp. 7415-7423 ◽  
Author(s):  
B. Gantt ◽  
N. Meskhidze ◽  
A. G. Carlton
Keyword(s):  
United States ◽  
Air Quality ◽  
San Francisco ◽  
Atmospheric Chemistry ◽  
Environmental Protection Agency ◽  
Regional Scale ◽  
The United States ◽  
Coastal Areas ◽  
Western United States ◽  
The Us

Abstract. The contribution of marine organic emissions to the air quality in coastal areas of the western United States is studied using the latest version of the US Environmental Protection Agency (EPA) regional-scale Community Multiscale Air Quality (CMAQv4.7) modeling system. Emissions of marine isoprene, monoterpenes, and primary organic matter (POM) from the ocean are implemented into the model to provide a comprehensive view of the connection between ocean biology and atmospheric chemistry and air pollution. Model simulations show that marine organics can increase the concentration of PM2.5 by 0.1–0.3 μg m−3 (up to 5%) in some coastal cities such as San Francisco, CA. This increase in the PM2.5 concentration is primarily attributed to the POM emissions, with small contributions from the marine isoprene and monoterpenes. When marine organic emissions are included, organic carbon (OC) concentrations over the remote ocean are increased by up to 50% (25% in coastal areas), values consistent with recent observational findings. This study is the first to quantify the air quality impacts from marine POM and monoterpenes for the United States, and it highlights the need for inclusion of marine organic emissions in air quality models.

scholarly journals Examining the impact of heterogeneous nitryl chloride production on air quality across the United States

2012 ◽  
Vol 12 (2) ◽  
pp. 6145-6183 ◽  
Author(s):  
G. Sarwar ◽  
H. Simon ◽  
P. Bhave ◽  
G. Yarwood
Keyword(s):  
United States ◽  
Air Quality ◽  
Atmospheric Chemistry ◽  
Forest Fires ◽  
The United States ◽  
Anthropogenic Sources ◽  
Reactive Nitrogen ◽  
Nitryl Chloride ◽  
The Impact ◽  
Hydrolysis Of

Abstract. The heterogeneous hydrolysis of dinitrogen pentoxide (N2O5) has typically been modeled as only producing nitric acid. However, recent field studies have confirmed that the presence of particulate chloride alters the reaction product to produce nitryl chloride (ClNO2) which undergoes photolysis to generate chlorine atoms and nitrogen dioxide (NO2). Both chlorine and NO2 affect atmospheric chemistry and air quality. We present an updated gas-phase chlorine mechanism that can be combined with the Carbon Bond 05 mechanism and incorporate the combined mechanism into the Community Multiscale Air Quality modeling system. We then update the current model treatment of heterogeneous hydrolysis of N2O5 to include ClNO2 as a product. The model, in combination with a comprehensive inventory of chlorine compounds, reactive nitrogen, particulate matter, and organic compounds, is used to evaluate the impact of the heterogeneous ClNO2 production on air quality across the United States for the months of February and September in 2006. The heterogeneous production increases ClNO2 in coastal as well as many in-land areas in the United States. Particulate chloride derived from sea-salts, anthropogenic sources, and forest fires activates the heterogeneous production of ClNO2. With current estimates of tropospheric emissions burden, it modestly enhances monthly mean 8-h ozone (up to 1–2 ppbv or 3–4%) but causes large increases (up to 13 ppbv) in isolated episodes. It also substantially reduce the mean total nitrate by up to 0.8–2.0 μg m−3 or 11–21%. Modeled ClNO2 accounts for up to 3–4% of the monthly mean total reactive nitrogen. Sensitivity results of the model suggest that ClNO2 formation is limited more by the presence of particulate chloride than by the abundance of N2O5.

scholarly journals The impact of marine organics on the air quality of the western United States

2010 ◽  
Vol 10 (3) ◽  
pp. 6257-6278 ◽  
Author(s):  
B. Gantt ◽  
N. Meskhidze ◽  
A. G. Carlton
Keyword(s):  
United States ◽  
Air Quality ◽  
Atmospheric Chemistry ◽  
Environmental Protection Agency ◽  
Regional Scale ◽  
The United States ◽  
Coastal Areas ◽  
Western United States ◽  
The Us ◽  
The Impact

Abstract. The impact of marine organic emissions to the air quality in coastal areas of the western United States is studied using the latest version of the US Environmental Protection Agency (EPA) regional-scale Community Multiscale Air Quality (CMAQv4.7) modeling system. Emissions of marine isoprene, monoterpenes, and primary organic matter (POM) from the ocean are implemented into the model to provide a comprehensive view of the connection between ocean biology and atmospheric chemistry and air pollution. Model simulations show that marine organics can increase the concentration of PM2.5 by 0.1–0.3 μg m−3 (up to 5%) in coastal cities. This increase in the PM2.5 concentration is primarily attributed to the POM emissions, with small contributions from the marine isoprene and monoterpenes. When marine organic emissions are included, organic carbon (OC) concentrations over the remote ocean are increased by up to 50% (25% in coastal areas), values consistent with recent observational findings. This study is the first to quantify the air quality impacts from marine POM and monoterpenes for the United States, and highlights the need for inclusion of marine organic emissions in air quality models.

scholarly journals Examining the impact of heterogeneous nitryl chloride production on air quality across the United States

2012 ◽  
Vol 12 (14) ◽  
pp. 6455-6473 ◽  
Author(s):  
G. Sarwar ◽  
H. Simon ◽  
P. Bhave ◽  
G. Yarwood
Keyword(s):  
United States ◽  
Air Quality ◽  
Atmospheric Chemistry ◽  
Forest Fires ◽  
The United States ◽  
Anthropogenic Sources ◽  
Reactive Nitrogen ◽  
Nitryl Chloride ◽  
The Impact ◽  
Hydrolysis Of

Abstract. The heterogeneous hydrolysis of dinitrogen pentoxide (N2O5) has typically been modeled as only producing nitric acid. However, recent field studies have confirmed that the presence of particulate chloride alters the reaction product to produce nitryl chloride (ClNO2) which undergoes photolysis to generate chlorine atoms and nitrogen dioxide (NO2). Both chlorine and NO2 affect atmospheric chemistry and air quality. We present an updated gas-phase chlorine mechanism that can be combined with the Carbon Bond 05 mechanism and incorporate the combined mechanism into the Community Multiscale Air Quality (CMAQ) modeling system. We then update the current model treatment of heterogeneous hydrolysis of N2O5 to include ClNO2 as a product. The model, in combination with a comprehensive inventory of chlorine compounds, reactive nitrogen, particulate matter, and organic compounds, is used to evaluate the impact of the heterogeneous ClNO2 production on air quality across the United States for the months of February and September in 2006. The heterogeneous production increases ClNO2 in coastal as well as many in-land areas in the United States. Particulate chloride derived from sea-salts, anthropogenic sources, and forest fires activates the heterogeneous production of ClNO2. With current estimates of tropospheric emissions, it modestly enhances monthly mean 8-h ozone (up to 1–2 ppbv or 3–4%) but causes large increases (up to 13 ppbv) in isolated episodes. This chemistry also substantially reduces the mean total nitrate by up to 0.8–2.0 μg m−3 or 11–21%. Modeled ClNO2 accounts for up to 6% of the monthly mean total reactive nitrogen. Sensitivity results of the model suggest that heterogeneous production of ClNO2 can further increase O3 and reduce TNO3 if elevated particulate-chloride levels are present in the atmosphere.

Urban form and air quality in the United States

2015 ◽  
Vol 139 ◽  
pp. 168-179 ◽  
Author(s):  
Joshua McCarty ◽  
Nikhil Kaza
Keyword(s):  
United States ◽  
Air Quality ◽  
Urban Form ◽  
The United States

scholarly journals Life cycle air quality impacts on human health from potential switchgrass production in the United States

2018 ◽  
Vol 114 ◽  
pp. 73-82 ◽  
Author(s):  
Sumil K. Thakrar ◽  
Andrew L. Goodkind ◽  
Christopher W. Tessum ◽  
Julian D. Marshall ◽  
Jason D. Hill
Keyword(s):  
United States ◽  
Life Cycle ◽  
Air Quality ◽  
Human Health ◽  
The United States

scholarly journals Air Pollution Increases Influenza Hospitalizations

2020 ◽  
Author(s):  
Gregor Singer ◽  
Joshua Graff Zivin ◽  
Matthew Neidell ◽  
Nicholas Sanders
Keyword(s):  
United States ◽  
Air Pollution ◽  
Air Quality ◽  
Seasonal Influenza ◽  
Hospital Admissions ◽  
The United States ◽  
Inpatient Hospitalization ◽  
Vaccination Rates ◽  
Health Burden ◽  
Severe Influenza

AbstractSeasonal influenza is a recurring health burden shared widely across the globe. We study whether air quality affects the occurrence of severe influenza cases that require inpatient hospitalization. Using longitudinal information on local air quality and hospital admissions across the United States, we find that poor air quality increases the incidence of significant influenza hospital admissions. Effects diminish in years with greater influenza vaccine effectiveness. Apart from increasing vaccination rates, improving air quality may help reduce the spread and severity of influenza.

scholarly journals Model analyses of atmospheric mercury: present air quality and effects of transpacific transport on the United States

2013 ◽  
Vol 13 (4) ◽  
pp. 9849-9893 ◽  
Author(s):  
H. Lei ◽  
X.-Z. Liang ◽  
D. J. Wuebbles ◽  
Z. Tao
Keyword(s):  
United States ◽  
Air Quality ◽  
Wet Deposition ◽  
Total Mercury ◽  
The United States ◽  
Atmospheric Mercury ◽  
Anthropogenic Sources ◽  
Mercury Deposition ◽  
Transpacific Transport ◽  
Mercury Cycle

Abstract. Atmospheric mercury is a toxic air and water pollutant that is of significant concern because of its effects on human health and ecosystems. A mechanistic representation of the atmospheric mercury cycle is developed for the state-of-the-art global climate-chemistry model, CAM-Chem (Community Atmospheric Model with Chemistry). The model simulates the emission, transport, transformation and deposition of atmospheric mercury (Hg) in three forms: elemental mercury (Hg(0)), reactive mercury (Hg(II)), and particulate mercury (PHg). Emissions of mercury include those from human, land, ocean, biomass burning and volcano related sources. Land emissions are calculated based on surface solar radiation flux and skin temperature. A simplified air–sea mercury exchange scheme is used to calculate emissions from the oceans. The chemistry mechanism includes the oxidation of Hg(0) in gaseous phase by ozone with temperature dependence, OH, H2O2 and chlorine. Aqueous chemistry includes both oxidation and reduction of Hg(0). Transport and deposition of mercury species are calculated through adapting the original formulations in CAM-Chem. The CAM-Chem model with mercury is driven by present meteorology to simulate the present mercury air quality during the 1999–2001 periods. The resulting surface concentrations of total gaseous mercury (TGM) are then compared with the observations from worldwide sites. Simulated wet depositions of mercury over the continental United States are compared to the observations from 26 Mercury Deposition Network stations to test the wet deposition simulations. The evaluations of gaseous concentrations and wet deposition confirm a strong capability for the CAM-Chem mercury mechanism to simulate the atmospheric mercury cycle. The results also indicate that mercury pollution in East Asia and Southern Africa is very significant with TGM concentrations above 3.0 ng m−3. The comparison to wet deposition indicates that wet deposition patterns of mercury are more affected by the spatial variability of precipitation. The sensitivity experiments show that 22% of total mercury deposition and 25% of TGM concentrations in the United States are resulted from domestic anthropogenic sources, but only 9% of total mercury deposition and 7% of TGM concentrations are contributed by transpacific transport. However, the contributions of domestic and transpacific sources on the western United States levels of mercury are of comparable magnitude.

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