WP4: Megacity Air Quality

 

Coordinated by N. Moussiopoulos (AUTH)

 

MEGAPOLI Partners involved: DMI, FORTH, AUTH, CNRS, FMI, NILU, UHel, UH-CAIR

 

Summary of progress toward objectives

Several physical and chemical parameterisations have already been implemented and are being tested in several megacities (e.g. Paris, Mexico City and Po Valley). Results of the performance evaluation of these tests are already being analysed and are revealing clues about the relative importance of the various parameterisations when examining megacity air quality and especially its relation to meteorology.
Progress is also being made with relation to the assessment of source contribution in megacities, the main focus being the Paris conurbation. For the moment, well known source apportionment methodologies are being tested in synthetic cases in order to evaluate the requirements and performance of each of them and later proceed with well informed choices in the case study of Paris. Discussions between modelling groups in WP4 have been initiated in order to explore the possibilities of using source apportionment findings in order to identify exposure patterns.
In the oncoming months, WP4 groups will seek to finalise the concrete performance assessment of the proposed zooming approaches, while ideas and suggestions are continuously being tested and challenged through application in urban test cases. We expect that the ongoing work on validation cases involving the 1st level MEGAPOLI regions will provide significant benefits on the improvement of methodologies, as well as the necessary calibration of existing parameterizations.

 

Summary details for each relevant WP deliverables, milestones, and tasks

Task 4.1: Multiscale physical processes - from the city to the street scale (lead: AUTH)

A variety of zooming approaches have been investigated by the MEGAPOLI WP4 teams for enhancing the numerical treatment of multiscale physical effects in existing and novel model implementations. The aim of such approaches is to improve modelling skill in simulating small-scale features through the use of dynamical downscaling (usually in the form of model coupling), introduction of improved parameterisations for scale-specific processes and support for flexible nesting of computational grids.

 

Metamodelling methods for mesoscale-microscale coupling
Interpolating metamodels have been suggested as an efficient means for implementing an effective two-way coupling between prognostic mesoscale and microscale models for flow calculations in densely-built urban areas. A novel scheme was developed for introducing effects of the urban canopy calculated on the microscale into a mesoscale calculation, by means of a two-way coupling between the mesoscale MEMO model (Moussiopoulos et al, 1993) and the microscale model MIMO (Ehrhard et al, 2000). A multi-dimensional interpolating metamodel is used as a computationally economical substitute for complex microscale calculations, enabling the bidirectional offline coupling between the two scales (Tsegas et al, 2008; 2009). The metamodel is calibrated over a sample set of microscale calculations in representative domains within the urban area under study (Figure 4.1.1a). During the two-way coupled run, area-averaged feedback from the microscale metamodel is assimilated back into the mesoscale domain by means of Newtonian relaxation. The coupled MEMO-MIMO system was used to simulate meteorological fields over the Paris greater area. The baseline performance of the mesoscale model was evaluated by comparing calculated quantities to measurements of meteorological parameters at several locations in and around the Paris urban area during the simulation period. Furthermore, quantities calculated from both nested domains were used in the comparison, in order to assess the effects of spatial discretisation as well as the small-scale forcings of the fine grid on the simulation accuracy. A successful application of any obstacle-resolving Microscale/CFD flow model requires the availability of high-quality, high-accuracy geometrical and morphology data. Sievinen et al (2009) have prepared a set of digital elevation maps (DEMs) covering an extended central area in Paris. An additional set of building height maps, generated by superimposing average urban height maps with detailed street and building geometry data, was used as a basis for determining the obstacle geometry of the metamodel calibration locations (Figure 4.1.1b). See more details in MEGAPOLI Deliverable D4.1.

 

     

(a)                                                                                           (b)

Figure 4.1.1 : (a) A metamodelling scheme for enabling offline coupling between the mesoscale meteorological model MEMO and the microscale/CFD model MIMO; and (b) 3D visualisation of urban canopy structure for a downtown location in Paris.

 

Aerosol effects in meteorological mesoscale modelling
Aerosols have a significant impact on the earth’s radiation budget by scattering and absorbing solar radiation thus decreasing the radiation absorbed at the surface and increasing low-level static stability. Modelling is becoming an important tool for investigating the intricate feedback mechanisms involved in the direct and indirect aerosol effects, further driving the ongoing evolution of computational tools towards the integration of meteorological and chemical-dispersion models. Recent developments in urban air pollution modelling have focused on the introduction of on-line coupling between aerosol modules and the driving meteorological models, aiming to a more accurate description of aerosol-induced radiative forcings in the atmosphere.
Aiming at a more accurate description of the feedbacks involved in the direct aerosol effect, an on-line coupled system was developed consisting of the mesoscale Eulerian meteorological model MEMO and the chemical transport model MARS-aero (Halmer, 2010). During the coupled operation, the 3D aerosol concentration fields calculated by MARS-aero are introduced back as input in the enhanced radiation module of MEMO by means of the OPAC (Optical Properties of Aerosols and Clouds) software library. For the calculation of the absolute optical properties, number densities for several of the OPAC aerosol component types are obtained from the concentration fields of appropriate aerosol aggregates which are provided by MARS-aero.
A synthetic test case was used to investigate the influence of aerosols on the radiation budget over a specified mesoscale computational area. The performance of the radiation module was assessed using a three-dimensional case with realistic dimensions and initial conditions, which was nevertheless simplified enough as to allow the influence of the aerosol direct effect to be isolated from other effects that would interfere in a real-world scenario. For the treatment of the synthetic case, the mesoscale boundary layer model MEMO was used with an extended version of the radiation model IRIS, by including the radiation module OPAC for the computation of the optical characteristics of the aerosols. The purpose of the test case was to examine the influence of aerosols of four different compositions on the evolution of meteorological quantities. The compositions correspond to four of the aerosol types defined in the OPAC data base, namely Continental clean (KS), Continental averagely polluted (KD), Continental polluted (KB) and Urban polluted (SB). The Continental clean aerosol represents land areas located away from populated areas and thus aerosol concentrations that are only weakly affected by anthropogenic emissions. The Continental average type of aerosol describes rural areas affected by anthropogenic emissions while the Continental polluted type of aerosol corresponds to land areas strongly influenced by human activities. Urban areas, which are strongly burdened by anthropogenic emissions, are represented by the urban polluted (SB) type of aerosol. A full specification of these aerosol types is given in Hess et al (1998). The four aerosol components with specific microphysical properties were considered as insoluble and water-soluble consist again of several substances. For the description of the size distributions of the individual aerosol components, log-normal distributions are used.  The vertical profiles of temperature calculated using the four aerosol types are shown in Figure 4.1.2a. The profiles shown refer to noon (12:00) of the fourth simulation day at a location 10 km downwind the inflow boundary (i.e. on the domain centre). Representation of the development of the speed profile over the length of the computational domain are shown in Figure 4.1.2b. See more details in MEGAPOLI Deliverable D4.1.  


Figure 4.1.2: (a) Temperature profiles calculated for the four aerosol types within the 2500 m domain. Profiles were calculated for a location 10 km downwind the inflow boundary (elevations are above sea level); and (b): Representation of the development of the speed profile over the length of the computational domain (2500 m height) (elevations are above sea level).


Urban and micro-scale modelling with Enviro-HIRLAM
High-resolution simulations with urbanisation using the Enviro-HIRLAM provide the possibility to incorporate urban effects into mesoscale meteorological and air pollution dispersion modelling. Applications of the model in the framework of WP4 have revealed significant effects on both the meteorological and concentration fields. The suggested multi-scale modelling system is certainly more expensive than traditional two-way nesting techniques but provides new insight into the underlying phenomena which requires further analysis. The Enviro-HIRLAM is a fully on-line integrated modeling system (Korsholm, 2009; Baklanov et al., 2008; Korsholm et al., 2008). It is based on the reference version of the HIgh Resolution Limited Area Model (HIRLAM) developed for numerical weather prediction (NWP) applications with implemented atmospheric chemical transport (ACT) modules into HIRLAM. The urban parameterisations which could be implemented into the Enviro-HIRLAM include the following: a) anthropogenic heat flux and roughness in the regional to global scales (Baklanov et al., 2008), b) a “building effects” parameterization (BEP) in the mesoscale and city-scale (Martilli et al, 2002), c) a soil model for the sub-mesoscale urban version, SM2-U (Dupont et al, 2006), and d) an obstacle-resolved approach (Nuterman 2008; Nuterman et al, 2008). Some of these urban parameterizations (mentioned above) have been implemented and tested for the operational DMI-HIRLAM NWP model with a focus on the Copenhagen metropolitan area and surroundings (Mahura et al., 2008ab; Mahura et al., 2009). Focusing more on the obstacle-resolved approach, microscale nesting can be realised with an aid of the Micro-scale Model for Urban Environment (M2UE; Nuterman 2008). It is a comprehensive Computational Fluid Dynamics (CFD) type obstacle-resolving urban wind flow and dispersion model. It is based on the Reynolds Averaged Navier-Stokes approach and two-equation kε turbulence closure. M2UE was developed in cooperation with the Tomsk State University (Nuterman et al, 2008). The necessary boundary and initial conditions for the nested M2UE model originate from the NWP model of rougher resolution by downscaling from regional to urban levels (i.e from 15 km to 5 km and down to finer resolution of 1.4-2.5 km). M2UE has been already tested with downscaling for urban air pollution and emergency preparedness applications in combination with the meteorological meso-scale model (Baklanov et al, 2008). However, the most interesting is possible up-scaling which is expected to take into account the street-level effects on formation of wind-flow and atmospheric transport of pollution on the local- and city-scales.A version of Enviro-HIRLAM model was used for down-scaling in the case of a selected industrial area of Copenhagen, where simulation of meteorological fields and air pollution within the selected urban area was carried out. For this area simulation was performed by the M2UE which is resolving real building structure and using boundary and initial conditions from the larger area. For sensitivity study of the release position two separate runs were carried out, where the release position was changed by 10 m (see positions 1 and 2 in Figure 4.4ab, respectively). For the first case (position 2) the release took place between 2 buildings within the main airflow, for the second case (position 1) the release occurred close to the building (i.e. within aerodynamic shadow). In Figure 4.4a the near surface velocity fields and iso-surfaces of concentrations for both release positions are presented. Detailed analysis shows that this small variation of the release location leads to a large change of the plume dispersion. In the first case it is transported rapidly between the buildings by the main airstream to the outer border. In the second case it is turned to the right and it is much more slowly transported through the other street canyon to the right border of the modelling domain. See more details in MEGAPOLI Deliverable D4.1.


 

Figure 4.1.3 : Near surface velocity field and isosurfaces of concentration: 10 m difference of release position (left and right) for the Copenhagen industrial area.


Task 4.2:
Multiscale chemical processes - from the city to the street scale (lead: FORTH)

FORTH has initiated work with new modules for inorganic (interactions of gases with dust, use of ISORROPIA-II for aerosol thermodynamics) and organic aerosol physicochemical transformations (new secondary organic aerosol yields and use of the volatility basis set) as well as the investigation of the effect of grid size on the simulation of gas and aerosol-phase chemical transformations. The PMCAMx chemical transport model (CTM) was used to simulate air quality focusing on the PM2.5 concentration and composition in the north-eastern United States using two grids: a uniform 36´36 km grid and one that has a nested subdomain with 12´12 km resolution. The performance of the model was evaluated using PM2.5 and gas-phase measurements from the mostly urban EPA Speciation Trends Network (STN) and the mostly rural Interagency Monitoring of Protected Visual Environments (IMPROVE) for a summer period in July 2001 and a winter period in January 2002.
UH-CAIR is performing model calculations of London using the WRF/CMAQ mesoscale model, while UHel had developed and is currently testing an aerosol dynamic model (SALSA) which will be implemented in SILAM and Enviro-HIRLAM for regional case studies.

 

Application of Multi-scale PMCAMx
Two simulations were performed for the same modelling domain in the Eastern US: one using the traditional coarse modelling domain that has been used in previous applications of PMCAMx in the area (Karydis et al. 2007) and one with a multi-scale grid “zooming” in the northeastern US.
Inputs to the model include horizontal wind components, temperature, pressure, water vapor, vertical diffusivity, clouds, and rainfall, all created using the meteorological model MM5 (Grell et al, 1995). The emission inventory used is the Midwest Regional Planning Organization’s Base E inventory LADCO (2003) with corrected EC emissions (Lane et al, 2007; Karydis et al, 2007). A different emission inventory is used for weekdays, Saturdays, and Sundays during both seasons. Ammonia emissions used in this model are from the Carnegie Mellon University ammonia emission inventory of Pinder et al (2004). The simulations with a coarse domain require 7.7 CPU operating hours on a Linux PC per simulation day while the multi-scale simulations require 9.6 CPU hours for the simulation of 24 hours (a 25% increase in computational cost). The ability of a CTM to reproduce past events is typically quantified by different statistical parameters, most of which are measures of the differences between model predictions and measurements. For the evaluation of the different versions of PMCAMx (coarse and fine grids) we use daily average PM measurements conducted during July 2001 and January 2002 throughout the Northeastern United States (inside the high resolution sub-domain) in 16 rural IMPROVE sites (rural Interagency Monitoring of Protected Visual Environments) and 13 STN sites (urban EPA Speciation Trends Network). A multiplier of 1.4 is applied to convert measured OC to organic mass (OM). The mean error (ERROR), mean bias (BIAS), fractional error (FERROR) and fractional bias (FBIAS) were calculated for coarse grid and finer grid predictions.
For example, sulfate is
the dominant hygroscopic PM2.5 component during the summer in the Northeastern US due to high SO2 emissions and favourable conditions for photochemical sulfate formation (warm and humid environment). Sulfate is mostly secondary and is formed relatively slowly (the oxidation of sulfur dioxide proceeds at a rate of a few percent per hour) resulting in relatively regional spatial distribution with small spatial gradients. Results of simulations are shown in Figure 4.2.1. More detailed analysis for other species such as nitrate, ammonium, organic mass,  elemental carbon, PM2.5 in the coarse and nested grids is given MEGAPOLI Deliverable D4.1. It was found that defining the model grid size can improve its ability in simulating physical and chemical processes simply by updating frequency thought it is a costly option in terms of computation resources and data requirement. It was therefore important to examine if for this application, the expected benefits justify requirements. In some cases, the finer grid scale resolved the texture of small-scale inhomogeneities for particle species better then the coarse grid. But there is no guarantee that the improvements are always such as intuitively expected. Nesting should not just be taken as simple grid refinement for selected areas. It has to be accompanied by the use of appropriately resolved and structured input data sets for emissions, land type and topography. Otherwise, the gain of accuracy by nesting may remain low. It was observed observed that the coarse grid predictions are characterized by a general smoothing of the concentrations through out the domain. During July predicted concentration of main species by the fine and coarse grid had small variations in average predicted concentrations. The fine grid captures the maximum concentration value of organic mass and elemental carbon with high peaks in the polluted areas. See more details in MEGAPOLI Deliverable D4.1.

      
Figure 4.2.1 : Predicted average ground concentration of sulfates (μg m-3) of the (ac) coarse and (bd) fine grids during (ab) July 2001 and (cd) January 2002.

 

Task 4.3: Interactions between air quality and meteorology/climate (lead: DMI)
First results by AUTH of an on-line version of MEMO/MARS to quantify effects of the direct aerosol effect have been proven successful. For the assessment of the coupled model system performance, meteorological parameters were calculated for a synthetic test case with a flat topography assuming different types of aerosol composition. A comparison of coupled calculations reveals that the radiative forcing due to the direct effect has a substantial impact on certain meteorological variables and the development of a lower inversion layer. At the same time, DMI has been using Enviro-HIRLAM model for the study of Paris, in particular in relation to the relative impact of urban effects vs. aerosol first and second indirect effects. This is being done using a domain covering 665´445 km2 around Paris, for the period 28/6/2005 - 03/07/2005. FORTH has been using PMCAMx-UF (UltraFine) to simulate together with the mass/composition distribution, the aerosol number distribution starting at 1 nm. This is in order to investigate the formation of new particles and their growth to CCN size. It will be important to compare the results to both the Paris measurement campaigns and also the results of Enviro-HIRLAM.
 
Task 4.4: Source apportionment – identification and quantification of relevant pathways (lead: AUTH)
A thorough review of source apportionment methods using a synthetic case over an urban area has been partially performed, building the model set-up to test some of the most used source apportionment methods, namely Principal Component Analysis (PCA), Positive Matrix Factorization (PMF), Chemical Mass Balance (CMB) and UNMIX. The recent availability of high resolution emission data for Paris will allow the application of some of those methods for a realistic case.
FORTH currently uses the Particle Source Apportionment Technology (PSAT) (Wagstrom et al, 2008) of PMCAMx to simulate directly the contributions of different source types and source areas to the concentrations of particulate matter over Europe. The major advantage of PSAT is that it describes the source contributions to secondary particulate matter together with that of primary.

Task 4.5:
Exposure estimates (lead: FMI)
During the reporting period, FMI have conducted various exposure model refinement and evaluation studies. The Institute of Health and Welfare (IHW) in Finland and the FMI team have developed methods for evaluating the exposures, especially using intake fractions, on an urban (Loh et al, 2009) and on an European scale (Tainio et al, 2009a). Several journal articles have been published in this area, most recently Tainio et al (2010). The aim is to apply the methodologies in Paris and London, in collaboration with the University of Hertfordshire and CNRS/Lisa.FMI have also evaluated population exposure distributions using an urban scale probabilistic exposure model (Hänninen et al, 2009), and analysed population exposure to primary fine particles from vehicular traffic and domestic wood combustion (Tainio et al, 2009b). There has also been an analysis of the influence of the model spatial resolution on the computed exposure values.
NILU has been developing a sub-grid variability method for the exposure assessments in WP4.


Deliverable 4.1: Evaluation of zooming approaches describing multiscale physical processes (lead: AUTH)
Report was written and available as report at the MEGAPOLI public web-site. Moussiopoulos N., Douros J., Tsegas G. (Eds.) (2010): Evaluation of Zooming Approaches De-scribing Multiscale Physical Processes. Deliverable D4.1, MEGAPOLI Scientific Report 10-03, MEGAPOLI-06-REP-2010-01, 41p.

Deliverable 4.2: Evaluation of zooming approaches describing multiscale chemical transformations (lead: FORTH)
Report was written and available as report at the MEGAPOLI public web-site. Dhurata Koraj, Spyros N. Pandis (2010): Evaluation of Zooming Approaches Describing Multis-Scale Chemical Transformations. Deliverable D4.2, MEGAPOLI Scientific Report 10-05, MEGAPOLI-08-REP-2010-01, 29p.

Deliverable 4.3: Investigation of meteorological patterns favouring development of urban air pollution episodes (lead: DMI)
Report was written and available as report at the MEGAPOLI public web-site. Baklanov A., Mahura A. (Eds.) (2010): Interactions between Air Quality and Meteorology, Deliverable D4.3, MEGAPOLI Scientific Report 10-10, MEGAPOLI-13-REP-2010-03, 48p.

Deliverable 4.4: Evaluation of Methodologies for Exposure Analysis in Urban Areas and Application to Selected Megacities (lead: FMI)
Report was written and available as report at the MEGAPOLI public web-site. Karppinen A., Kangas L., Riikonen K., Kukkonen J., Soares J., Denby B., Cassiani M., Finardi S., Radice P., (2010): Evaluation of Methodologies for Exposure Analysis in Urban Areas and Application to Selected Megacities. Deliverable D4.4, MEGAPOLI Scientific Report 10-18, MEGAPOLI-21-REP-2010-11, 29p.

Deliverable 4.5: Exposure Maps for Selected Megacities (lead: FMI)
Report was written and available as report at the MEGAPOLI public web-site. Soares J., A. Karppinen, B. Denby, S. Finardi, J. Kukkonen, M. Cassiani, P. Radice, M.Williams (2010): Exposure Maps for Selected Megacities. Deliverable D4.5, MEGAPOLI Scientific Report 10-19, MEGAPOLI-22-REP-2010-11, 26p.

Deliverable 4.6: Evaluation of Source Apportionment Methods (lead: AUTH)
Report was written and available as report at the MEGAPOLI public web-site. Moussiopoulos N., Douros J., Tsegas G. (Eds) (2010): Evaluation of Source Apportionment Methods. Deliverable D4.6, MEGAPOLI Scientific Report 10-22, MEGAPOLI-25-REP-2010-12, 53p.

Milestone 4.1: Selection of a Megacity for exposure estimates and mapping (lead: FMI, AUTH; month 18) has been achieved.

 

Significant results: Methodologies and scientific achievements related to WP including partners’ contributions

The magnitude of urban effects in comparison to the first and second indirect aerosol feedbacks has been studied by DMI using the Paris area as a test case (specific episode), by means of the on-line coupled Enviro-HIRLAM model. Results indicated that aerosol indirect effects modify daytime temperatures by up to 4ºC and PBL height by up to 900 m. NO2 concentrations were shown to be moderately affected. Urban effects are interacting in a non-linear way with effects of urban emissions, therefore in order to model correctly the effects of megacities online coupled/integrated models with two-way interaction of meteorological and chemical/aerosol processes need to be considered. Urban vs. aerosol feedbacks were estimated to exhibit the same order of magnitude effects on mixing height, but with strong sensitivity of chemistry and a strong non-linearity. The fist indirect effect was found to have a much smaller influence than the second one, while indirect effects induce large changes in NO2. Urban effects, on the other hand, mainly influence values of temperature at 2 m.
Based on the above results, a first estimate of the expected effects of urban/megacity on the climate change/global warming can be attempted: on the local and meso-scales, an observable effect is expected to occur, both via the influence of the Urban Heat Island (UHI) and the city plume. On the regional and continental scale, such effects can also be expected since the urban plume can extend up to thousands of km. On a global scale, the effect of UHI is expected to be diminished but the influence of the city plume (in particular, GHGs and aerosols) needs to be further investigated.
A revised version of the PMCAMx model (called PMCAMx-2008) developed by FORTH, was applied to Mexico City and evaluated against the measurements collected during the MCMA-2003 study (Karydis et al, 2009; Tsimpidi et al, 2009). The results of the evaluation were very encouraging about the updated model which will be used in the rest of the MEGAPOLI project. The effect of grid size on the simulation of gas and aerosol-phase chemical transformations has been investigated for the Eastern US domain (Koraj and Pandis, 2009). The model results were evaluated against measurements by the STN and IMPROVE networks. The improvement in the model predictions going from a 36´36 km domain to a 12´12 km in this area was small in the summer and modest during the winter.
Meteorological simulations for the Paris area were performed by AUTH using the MEMO model under different model configurations. Sensitivity tests against several data assimilation schemes were investigated in order to optimise the model performance in respect to the driving boundary conditions. Statistical assessment of the simulation has been performed using statistical indicators (Index of Agreement, Correlation Coefficient), providing encouraging results. A metamodelling methodology has also been developed for the implementation of an efficient two-way coupling between a mesoscale and a microscale CFD model for calculations over extended densely-built urban areas. The model system was applied to a meteorological case covering the urban area of Athens and the results were compared to the traditional approach of modifying the roughness length over urban areas. It was found that the coupled system on average predicts lower wind velocities over most of the urban cells while the production of turbulent kinetic energy becomes pronounced at the second model layer (30-40m). The distribution of wind directions calculated for a downtown location indicates a tendency to align local flows with the prevailing street direction. Further applications of the coupled model system include a summer case for Paris, currently in progress. It is expected that the improved accuracy of the flows calculated by the coupled system will enhance the resolving power of chemical dispersion models in urban applications.
AUTH has also been aiming at a more accurate description of the feedbacks involved in the direct aerosol effect, through an on-line coupled system that was developed consisting of the mesoscale Eulerian meteorological model MEMO and the chemical transport model MARS-aero. For the assessment of the coupled model system performance, meteorological parameters were calculated for a synthetic test case with a flat topography assuming different types of aerosol composition. A comparison of coupled calculations revealed that the radiative forcing due to the direct effect has a substantial impact on meteorological variables and the development of a lower inversion layer.
Exposure model refinement and evaluation studies were conducted by FMI together with the  Institute of Health and Welfare (IHW) in Finland (Loh et al, 2009) as well as on an European scale (Tainio et al, 2009a). An urban scale probabilistic exposure model (Hänninen et al, 2009) was also investigated for the evaluation of population exposure distributions. Exposure to primary fine particles from vehicular traffic and domestic wood combustion has been analysed in Tainio et al (2009b).

 

Socio-economic relevance and policy implications

WP4 places a particular emphasis on the interactions between air quality and meteorology at the megacity scale which in turn has impacts on regional to global scales and potential mitigation options. These impacts are especially pronounced in major urban centres, rendering improved knowledge on the importance of multi-scale transport processes, an important aspect of this WP. The work being done has begun to produce results by the application of fine-scale air quality models in selected cities (e.g. Paris) and novel, more accurate estimations of population exposure. Detailed concentration fields are of great relevance both to humans but also to the ecosystem and will result (in other WPs) in the quantification the impacts, resulting among others to significant economic damage. Improved knowledge about physico-chemical processes and methodologies will support, through incorporation to an integrated framework, the wider European policy in its objective to decouple economic growth and environmental degradation and to help promote sustainable production.

 

Discussion and conclusion

Most of the work of the WP 4 is progressing as planned.  Model development and testing  has taken place at various levels and will be able to provide the material for extracting important conclusions relevant to the scientific questions that have been posed.

 

List of WP4 reports, publications, presentations and references

 

Moussiopoulos N., Douros J., Tsegas G. (Eds.) (2010): Evaluation of Zooming Approaches Describing Multiscale Physical Processes. Deliverable D4.1, MEGAPOLI Scientific Report 10-03, MEGAPOLI-06-REP-2010-01, 41p, ISBN: 978-87-992924-6-2; http://megapoli.dmi.dk/publ/MEGAPOLI_sr10-03.pdf
Dhurata Koraj, Spyros N. Pandis (2010): Evaluation of Zooming Approaches Describing Multiscale Chemical Transformations. Deliverable D4.2, MEGAPOLI Scientific Report 10-05, MEGAPOLI-08-REP-2010-01, 29p, ISBN: 978-87-992924-8-6; http://megapoli.dmi.dk/publ/MEGAPOLI_sr10-05.pdf

d'Almeida, G.A., P. Koepke and E.P. Shettle, (1991): Atmospheric Aerosols: Global Climatology and Radiative Characteristics, A. Deepak Publishing, p. 561,

Baklanov, A., U. Korsholm, A. Mahura, C. Petersen, A. Gross, (2008): ENVIRO-HIRLAM: on-line coupled modelling of urban meteorology and air pollution, Advances in Science and Research, 2, 41-46

Baklanov A. and R. Nuterman, (2009): Multi-scale atmospheric environment modelling for urban areas. Advances in Science and Research, 3, 53-57.

Deepak, A. and H.E. Gerber, Eds., (1983): Report of the experts meeting on aerosols and their climatic effects, WCP-55, page 107.

Dupont, S. and P. Mestayer, (2006): Parameterization of the Urban Energy Budget with the Submesoscale Soil Model, J. Appl. Meteorol. Clim., 45(12), 1744–1765.

Ehrhard, J., I.A. Khatib, C. Winkler, R. Kunz, N. Moussiopoulos, and G. Ernst, (2000): ‘The microscale model MIMO: Development and assessment’, Journal of Wind Engineering and Industrial Aerodynamics, 85, 163-176.

Flassak, T., (1990): Ein nicht-hydrostatisches Modell zur Beschreibung der Dynamik der planetaren Grenzschicht, VDI-Verlag, Dusseldorf, Fortschr.-Ber., VDI Reihe 15 Nr. 74, p. 205.

Gaydos T. M., R. Pinder, B. Koo, K.M. Fahey, G. Yarwood, and S.N. Pandis, (2007): Development and application of a three-dimensional aerosol chemical transport model, PMCAMx, Atmos. Environ., 12, 2594-2611.

Grell, G.A., J. Dudia, and D.R. Stauffer, (1995): ‘A description of the fifth generation Penn State/NCAR Mesoscale Model (MM5)’, NCAR, Tech. Note NCAR/TN-398 + STR, Natl. Cent. for Atmos. Res., Boulder, Colo.

Halmer, G., (2010), PhD thesis (in preparation)

Halmer, G., G. Tsegas, I. Douros, and N. Moussiopoulos, (2010): Using a coupled meteorological and chemistry transport model to evaluate the impact of the aerosol direct effect on meteorology and concentration fields in Paris, submitted for publication.

Hänninen, Ο., M. Kauhaniemi, A. Karppinen, J. Kukkonen, A. Kousa, and M. Jantunen, (2009): Inter-comparison of predicted population exposure distributions during four selected episodes in Helsinki and evaluation against measured data. International Journal of Environment and Pollution., 40, 248-266.

Hess, M., P. Koepke and I. Schult, (1998): Optical Properties of Aerosols and Clouds: The Software Package OPAC, Bulletin of the American Meteorological Society, Vol. 79, No. 5, 831-844.

Karydis, V.A., A.P. Tsimpidi, and S.N. Pandis, (2007): Evaluation of a three-dimensional chemical transport model (PMCAMx) in the Eastern United States for all four seasons, J. Geophys. Res., 112 D14211.

Karydis V.A., A.P. Tsimpidi, C. Fountoukis, A. Nenes, M. Zavala, W. Lei, L.T. Molina, and S.N. Pandis, (2009): Simulating the fine and coarse inorganic particulate matter concentrations in a polluted Megacity, Atmos. Environ., in press.

Koepke, P., M. Hess, I. Schult and E.P. Shettle, (1997): Global Aerosol Data Set, MPI Meteorologie Hamburg Report Nr. 243, p. 44

Koraj D. and S.N. Pandis, (2009): Evaluation of the particulate matter performance of a three-dimensional chemical transport model at different horizontal grid resolutions, in preparation.

Korsholm U., (2009): Integrated modeling of aerosol indirect effects - development and application of a chemical weather model, PhD thesis University of Copenhagen, Niels Bohr Institute and DMI, Research Department.http://www.dmi.dk/dmi/sr09-01.pdf

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FP7 EC MEGAPOLI, 2008-2011