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Journal Article•DOI•

Performance characteristics of MM5-SMOKE-CMAQ for a summer photochemical episode in southeast England, United Kingdom

Ye Yu1, Ye Yu2, Ranjeet S. Sokhi2, N. Kitwiroon2, D.R. Middleton3, Bernard Fisher4 •
Chinese Academy of Sciences1, University of Hertfordshire2, Met Office3, Environment Agency4
01 Jun 2008-Atmospheric Environment (Pergamon)-Vol. 42, Iss: 20, pp 4870-4883
TL;DR: In this paper, a Mesoscale Model (MM5), Sparse Matrix Operator Kernel Emissions (SMOKE) and Community Multiscale Air Quality (CMAQ) model has been applied to a summer photochemical period in southeast England, UK.
Abstract: In this study a modelling system consisting of Mesoscale Model (MM5), Sparse Matrix Operator Kernel Emissions (SMOKE) and Community Multiscale Air Quality (CMAQ) model has been applied to a summer photochemical period in southeast England, UK. Ozone (O3), nitrogen dioxide (NO2) and particulate matter (PM2.5) concentrations modelled with different horizontal grid resolutions (9 and 3 km) were evaluated against available ground-level observations from the UK Automatic Urban and Rural Network (AURN) and London Air Quality Network (LAQN) for the period of 24–28 June 2001 with a focus on O3 predictions. This effort, which represents the first comprehensive performance evaluation of the modelling system over a UK domain, reveals that CMAQ's ability to reproduce surface O3 observations varies with O3 concentrations. It underpredicts O3 mixing ratios on high-O3 days and overpredicts the maximum and minimum hourly O3 values for most low-O3 days. Model sensitivity analysis with doubled anthropogenic NOx or volatile organic compounds (VOC) emissions and analysis of the daylight-averaged levels of OX (sum of O3 and NO2) as a function of NOx revealed that the undereprediction of peak O3 concentrations on high-O3 days is caused by the underprediction of regional contribution and to a lesser extent local production, which might be related to the underestimation of European emissions in EMEP inventory and the lacked reactivity of the modelled atmosphere. CMAQ systematically underpredicts hourly NO2 mixing ratios but captures the temporal variations. The normalized mean bias for hourly NO2, although much larger than that for O3, falls well within the generally accepted range of −20% to −50%. CMAQ with both resolutions (9 and 3 km) significantly underpredicts PM2.5 mass concentrations and fails to reproduce its temporal variations. While model performance for O3 and PM2.5 are not very sensitive to model grid resolutions, a better agreement between modelled and measured hourly NO2 mixing ratios was achieved with higher resolution. Further investigation into the uncertainties in meteorological input, uncertainties in emissions, as well as representation of physical and chemical processes (e.g. chemical mechanism) in the model is needed to identify the causes for the discrepancies between observations and predictions.

Summary (2 min read)

Jump to: [1. Introduction] – [2.1. Modelling period and CMAQ configuration] – [2.2.2. Emissions] – [2.2.3. Initial and boundary conditions] – [3.1. Meteorological predictions] – [3.2.3. Fine particulate matter (PM2.5)] and [5. Conclusions]

1. Introduction

  • Especially in transportation and in industry, pollutant concentrations in many European cities are still likely to exceed ambient air quality standards and guidelines.
  • Elevated concentrations of tropospheric ozone (O3), nitrogen dioxide (NO2) and fine particulate matter are known to have negative effects on human health and the environment (e.g. Englert, 2004; Koop and Tole, 2006), and to a larger extent have important influence on the global atmospheric chemistry and climate change (Jenkin and Clemitshaw, 2000).
  • During the last two decades different air quality models, ranging from simple statistical models to fully threedimensional (3-D) comprehensive Eulerian models, have been developed in Europe and elsewhere.
  • The purpose of the present study is to apply CMAQ to the UK domain and evaluate its ability to simulate ambient concentrations of O3, NO2 and PM2.5 in the southeast of England during a summer (June 2001) air pollution episode.

2.1. Modelling period and CMAQ configuration

  • The degree of severity of summertime photochemical episodes largely depends on daytime air temperature, and high summertime air pollution events are almost always associated with anticyclonic conditions and temperatures in excess of 28–30 1C (UK PORG, 1997).
  • Fig. 1a shows the CMAQ modelling domain that consists of four nested domains with resolutions of 81, 27, 9 and 3 km.
  • Vertical layers were unevenly distributed with fifteen layers in the lowest kilometre and a surface layer of approxi- Please cite this article as: Yu, Y., et al., Performance characteristics of southeast England, United Kingdom.
  • 2. Model input preparation 2.2.1. Meteorology The Fifth-generation Pennsylvania State University–National Center for Atmospheric Research (NCAR) MM5, version 3 (Dudhia et al., 2004) was used to generate meteorological fields for CMAQ.

2.2.2. Emissions

  • Point source emissions were extracted from the European Pollutant Emission Register (EPER, http://www.eper.cec.eu.int/) and NAEI database, for non-UK and UK point sources, respectively.
  • It is assumed that the speciation profile for the UK could be applied across Europe without further adjustment.
  • Values of ei and D are taken from Sanderson (2002); gi is the environmental correction factor accounting for the dependence on temperature and radiation (Guenther et al., 1995).
  • Then the 44 CORINE land use classes were aggregated into four ecosystems (i.e. grass, broadleaf forest, needle leaf forest and shrub) and the fraction of the area of each grid cell covered by each ecosystem class and the associated emissions of isoprene and monoterpenes was calculated using the hourly temperature and solar radiation values from MM5.

2.2.3. Initial and boundary conditions

  • The initial and boundary conditions for the coarsest CMAQ domain were generated based on monthly mean data from the UK Met Office global 3-D Lagrangian tropospheric chemistry model .
  • This model outputs concentrations of 26 species with a horizontal resolution of 51 latitude 51 longitude and nine vertical layers extending from surface up to 150 hPa (Collins et al., 1997).
  • The initial and boundary conditions for the inner three domains are provided by the coarser domain.

3.1. Meteorological predictions

  • The MM5 modelled near-surface temperature, wind speed and wind direction were compared to hourly weather observations from 29 land surface stations archived at the Met Office Integrated Data Archive System (MIDAS; UK Meteorological Office, 2006).
  • These values reflect averages over space (all monitoring stations within the 3 kmgrid CMAQ domain) and time (all hours in the simulation period).
  • The model is able to reproduce the major features of the observed wind and temperature fields and the modelled profiles show a generally good agreement with measurements.
  • The locations of air quality monitoring sites used in the evaluation are shown in Fig. 1b.
  • In addition to the statistical measures used in Section 3.1, the correlation coefficient R was also calculated to quantify the model performance.

3.2.3. Fine particulate matter (PM2.5)

  • Hourly measurements of PM2.5 are available at four sites within the evaluation domain (one of them is located at roadside and is not included in the present study).
  • The limited availability of PM2.5 mass concentration and composition data makes the results of the model performance analysis less conclusive and robust; however, the analysis still provides a general indication of the model performance.
  • The above results on O3 predictions reveal a general underprediction of the hourly and daily maximum 8-h mean O3 mixing ratios by CMAQ for the studied area, especially on high-O3 days.
  • Previous study by Clapp and Jenkin (2001) shows that the level of OX (the sum of O3 and NO2) at a given location is made up of NOx-independent regional contribution (the intercept) and NOxdependent local contribution (the slope).
  • Please cite this article as: Yu, Y., et al., Performance characteristics of southeast England, United Kingdom.

5. Conclusions

  • A performance evaluation of MM5–SMOKE–CMAQ modelling system for southeast England, UK, for a summer photochemical episode has been presented.
  • The evaluation shows that CMAQ tends to underpredict hourly O3 mixing ratios on high-O3 days and overpredict the maximum and minimum O3 mixing ratios for most low-O3 days.
  • NOx emissions from soil were not accounted for in the present study.
  • The authors are thankful to Richard Derwent for providing the STOCHEM simulations.

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Journal Article•DOI•
Tropospheric ozone and its precursors from the urban to the global scale from air quality to short-lived climate forcer

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Paul S. Monks1, Alexander T. Archibald2, Augustin Colette, Owen R. Cooper3, Mhairi Coyle, Richard G. Derwent4, David Fowler, Claire Granier3, Claire Granier5, Claire Granier6, Kathy S. Law5, Gina Mills, David Stevenson7, Oksana Tarasova, Valérie Thouret8, E. von Schneidemesser9, Roberto Sommariva1, Oliver Wild10, Martin L. Williams11 •
University of Leicester1, University of Cambridge2, Cooperative Institute for Research in Environmental Sciences3, Newbury College4, University of Paris5, Earth System Research Laboratory6, University of Edinburgh7, Paul Sabatier University8, Potsdam Institute for Climate Impact Research9, Lancaster University10, King's College London11
13 Aug 2015-Atmospheric Chemistry and Physics
TL;DR: In this paper, a review examines current understanding of the processes regulating tropospheric ozone at global to local scales from both measurements and models and takes the view that knowledge across the scales is important for dealing with air quality and climate change in a synergistic manner.
Abstract: Ozone holds a certain fascination in atmospheric science. It is ubiquitous in the atmosphere, central to tropospheric oxidation chemistry, yet harmful to human and ecosystem health as well as being an important greenhouse gas. It is not emitted into the atmosphere but is a by-product of the very oxidation chemistry it largely initiates. Much effort is focussed on the reduction of surface levels of ozone owing to its health impacts but recent efforts to achieve reductions in exposure at a country scale have proved difficult to achieve due to increases in background ozone at the zonal hemispheric scale. There is also a growing realisation that the role of ozone as a short-lived climate pollutant could be important in integrated air quality climate-change mitigation. This review examines current understanding of the processes regulating tropospheric ozone at global to local scales from both measurements and models. It takes the view that knowledge across the scales is important for dealing with air quality and climate change in a synergistic manner.

877 citations

Cites background from "Performance characteristics of MM5-..."

  • ...Given the strong NOx-O3 (sometimes referred to as Ox, Zlatev et al., 1992; Yu et al., 2008, see also Fig....

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Journal Article•DOI•
A review of operational, regional-scale, chemical weather forecasting models in Europe

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Jaakko Kukkonen1, Taru Olsson2, Taru Olsson1, David M. Schultz1, David M. Schultz2, David M. Schultz3, Alexander Baklanov4, T. Klein5, Ana Isabel Miranda6, Alexandra Monteiro6, Marcus Hirtl7, V. Tarvainen1, Michael Boy2, Vincent-Henri Peuch8, Anastasia Poupkou9, Ioannis Kioutsioukis9, Sandro Finardi, Mikhail Sofiev1, Ranjeet S. Sokhi10, Kari E. J. Lehtinen1, Kari E. J. Lehtinen11, Kostas Karatzas9, R. San José12, Marina Astitha13, George Kallos14, Martijn Schaap, E. Reimer15, Hermann Jakobs16, Kryštof Eben17 •
Finnish Meteorological Institute1, University of Helsinki2, University of Manchester3, Danish Meteorological Institute4, Swedish Meteorological and Hydrological Institute5, University of Aveiro6, Central Institution for Meteorology and Geodynamics7, European Centre for Medium-Range Weather Forecasts8, Aristotle University of Thessaloniki9, University of Hertfordshire10, University of Eastern Finland11, Technical University of Madrid12, The Cyprus Institute13, National and Kapodistrian University of Athens14, Free University of Berlin15, University of Cologne16, Academy of Sciences of the Czech Republic17
02 Jan 2012-Atmospheric Chemistry and Physics
TL;DR: In this article, chemical weather forecasting models are described and compared on regional and continental scales in Europe, and the most prominent gaps of knowledge are highlighted for the following selected focus areas: emission inventories, the integration of numerical weather prediction and atmospheric chemical transport models, boundary conditions and nesting of models, data assimilation of the various chemical species, improved understanding and parameterization of physical processes, better evaluation of models against data and the construction of model ensembles.
Abstract: Numerical models that combine weather forecasting and atmospheric chemistry are here referred to as chemical weather forecasting models. Eighteen operational chemical weather forecasting models on regional and continental scales in Europe are described and compared in this article. Topics discussed in this article include how weather forecasting and atmospheric chemistry models are integrated into chemical weather forecasting systems, how physical processes are incorporated into the models through parameterization schemes, how the model architecture affects the predicted variables, and how air chemistry and aerosol processes are formulated. In addition, we discuss sensitivity analysis and evaluation of the models, user operational requirements, such as model availability and documentation, and output availability and dissemination. In this manner, this article allows for the evaluation of the relative strengths and weaknesses of the various modelling systems and modelling approaches. Finally, this article highlights the most prominent gaps of knowledge for chemical weather forecasting models and suggests potential priorities for future research directions, for the following selected focus areas: emission inventories, the integration of numerical weather prediction and atmospheric chemical transport models, boundary conditions and nesting of models, data assimilation of the various chemical species, improved understanding and parameterization of physical processes, better evaluation of models against data and the construction of model ensembles. © 2012 Author(s).

266 citations

Journal Article•DOI•
SMOKE for Europe - adaptation, modification and evaluation of a comprehensive emission model for Europe

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Johannes Bieser1, Armin Aulinger, Volker Matthias, Markus Quante1, Peter J. H. Builtjes2 •
Lüneburg University1, Free University of Berlin2
25 Jan 2011-Geoscientific Model Development
TL;DR: In this paper, the US EPA regional emission model SMOKE was adopted and modified to create temporally and spatially distributed emission for Europe and surrounding countries based on official reports and public domain data only.
Abstract: . The US EPA regional emission model SMOKE was adopted and modified to create temporally and spatially distributed emission for Europe and surrounding countries based on official reports and public domain data only. The aim is to develop a flexible model capable of creating consistent high resolution emission data for long-term runs of Chemical Transport Models (CTMs). This modified version of SMOKE, called SMOKE for EUROPE (SMOKE-EU) was successfully used to create hourly gridded emissions for the timespan 1970–2010. In this paper the SMOKE-EU model and the underlying European datasets are introduced. Emission data created by SMOKE-EU for the year 2000 are evaluated by comparison to data of three different state-of-the-art emission models. SMOKE-EU produced a range of values comparable to the other three datasets. Further, concentrations of criteria pollutants calculated by the CTM CMAQ using the four different emission datasets were compared against EMEP measurements with hourly and daily resolution. Using SMOKE-EU gave the most reliable modelling of O3, NO2 and SO42−. The amount of simulated concentrations within a factor of 2 (F2) of the observations for these species are: O3 (F2 = 0.79, N = 329 197), NO2 (F2 = 0.55, N = 11 465) and SO42− (F2 = 0.62, N = 17 536). The lowest values were found for NH4+ (F2 = 0.34, N = 7400) and NO3− (F2 = 0.25, N = 6184). NH4+ concentrations were generally overestimated, leading to a fractional bias (FB) averaged over 22 measurement stations of (FB = 0.83 ± 0.41) while better agreements with observations were found for SO42− (FB = 0.06 ± 0.38, 51 stations) and NO3− (FB = 0.13 ± 0.75, 18 stations). CMAQ simulations using the three other emission datasets were similar to those modelled using SMOKE-EU emissions. Highest differences where found for NH4+ while O3 concentrations were almost identical.

91 citations

Cites methods from "Performance characteristics of MM5-..."

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  • ...In Europe, for example, SMOKE has been adapted to use the national emission inventories of Spain and the UK (Borge et al., 2008; Yu et al., 2008)....

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  • ...Yu et al. (2008) adapted the SMOKE model to create emissions for the UK....

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Goddard Space Flight Center1, University of Maryland, College Park2, Morgan State University3, National Center for Atmospheric Research4, Langley Research Center5
08 Jul 2014-Journal of Applied Meteorology and Climatology
TL;DR: In this article, the role of the Chesapeake Bay breeze on surface air quality, pollutant transport, and boundary layer venting was investigated along with in situ aircraft observations in an 11-day ship-based field campaign.
Abstract: Meteorological and air-quality model simulations are analyzed alongside observations to investigate the role of the Chesapeake Bay breeze on surface air quality, pollutant transport, and boundary layer venting. A case study was conducted to understand why a particular day was the only one during an 11-day ship-based field campaign on which surface ozone was not elevated in concentration over the Chesapeake Bay relative to the closest upwind site and why high ozone concentrations were observed aloft by in situ aircraft observations. Results show that southerly winds during the overnight and early-morning hours prevented the advection of air pollutants from the Washington, D.C., and Baltimore, Maryland, metropolitan areas over the surface waters of the bay. A strong and prolonged bay breeze developed during the late morning and early afternoon along the western coastline of the bay. The strength and duration of the bay breeze allowed pollutants to converge, resulting in high concentrations locally near the bay-breeze front within the Baltimore metropolitan area, where they were then lofted to the top of the planetary boundary layer (PBL). Near the top of the PBL, these pollutants were horizontally advected to a region with lower PBL heights, resulting in pollution transport out of the boundary layer and into the free troposphere. This elevated layer of air pollution aloft was transported downwind into New England by early the following morning where it likely mixed down to the surface, affecting air quality as the boundary layer grew.

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Cites background from "Performance characteristics of MM5-..."

  • ..., sulfate formation and boundary layer venting through fair-weather cumulus clouds and localscale circulations, such as sea breezes) affect air quality (Gonçalves et al. 2009; Im et al. 2010; Jimenez et al. 2005, 2006, 2007; Lee et al. 2008; Loughner et al. 2011; Ortega et al. 2009; Parra et al. 2006; Perez et al. 2006; San Jose et al. 2007; Stein et al. 2007; Yu et al. 2008)....

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  • ...…and localscale circulations, such as sea breezes) affect air quality (Gonçalves et al. 2009; Im et al. 2010; Jimenez et al. 2005, 2006, 2007; Lee et al. 2008; Loughner et al. 2011; Ortega et al. 2009; Parra et al. 2006; Perez et al. 2006; San Jose et al. 2007; Stein et al. 2007; Yu et al. 2008)....

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Journal Article•DOI•
Evaluation of a CMAQ simulation at high resolution over the UK for the calendar year 2003

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Charles Chemel1, Ranjeet S. Sokhi1, Ye Yu2, Ye Yu1, Garry Hayman, Keith Vincent3, Anthony J. Dore, Y.S. Tang, H.D. Prain1, Bernard Fisher4 •
University of Hertfordshire1, Chinese Academy of Sciences2, AeA3, Environment Agency4
01 Aug 2010-Atmospheric Environment
TL;DR: In this paper, a comprehensive evaluation of the performance of the Community Multiscale Air Quality (CMAQ) modelling system version 4.6 was conducted in support of pollution assessment in the UK for the calendar year 2003.
Abstract: A comprehensive ‘operational’ evaluation of the performance of the Community Multiscale Air Quality ( CMAQ ) modelling system version 4.6 was conducted in support of pollution assessment in the UK for the calendar year 2003. The model was run on multiple grids using one-way nests down to a horizontal resolution as fine as 5 km over the whole of the UK. The model performance was evaluated for pollutants with standards and limit values ( e.g. O 3 , PM 10 ) and species contributing to acidic and nitrogenous deposition ( e.g. NH 3 , SO 4 2– , NO 3 – , NH 4 + ) against data from operational national monitoring networks. The key performance characteristics of the modelling system were found to be variable according to acceptance criteria and to depend on the type ( e.g. urban, rural) and location of the sites, as well as on the time of the year. As regards the techniques that were used for ‘operational’ evaluation, performance generally complied with expected levels and ranged from good ( e.g. O 3 , SO 4 2– ) to moderate ( e.g. PM 10 , NO 3 – ). At a few sites low correlations and large standard deviations for some species ( e.g. SO 2 ) suggest that these sites are subject to local factors ( e.g. topography, emission sources) that are not well described in the model. Overall, the model tends to over predict O 3 and under predict aerosol species (except SO 4 2– ). Discrepancies between predicted and observed concentrations may be due to a variety of intertwined factors, which include inaccuracies in meteorological predictions, chemical boundary conditions, temporal variability in emissions, and uncertainties in the treatment of gas and aerosol chemistry. Further work is thus required to investigate the respective contributions of such factors on the predicted concentrations.

55 citations

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Frequently Asked Questions (2)
Q1. What have the authors contributed in "Performance characteristics of mm5–smoke–cmaq for a summer photochemical episode in southeast england, united kingdom" ?

In this study the Mesoscale Model ( MM5 ) –Sparse Matrix Operator Kernel Emissions ( SMOKE ) –Community Multiscale Air Quality ( CMAQ ) modelling system has been applied to a summer photochemical period in southeast England, UK. Further investigation into the uncertainties in UN 95 97 99 101 103 e front matter r 2008 Elsevier Ltd. 

Further studies, however, are needed to explore how the model response to uncertainties linked to different processes of tropospheric chemistry modelling, namely large-scale pollution transport, refinement of emission inventory, as well as representation of the physical and chemical processes ( e. g. enhanced VOC reactivity under episodic conditions ).