D E S C R I P T I O N O F W O R K - MEGAPOLI - Dmi

MEGAPOLI 212520
WP4: Megacity Air Quality
Work package number 4 Start date or starting event: Month 6
Work package title Megacity Air Quality
Activity Type RTD
Participant number 1 2 5 6 7 12 17 18
Person-months per participant: 8 12 19 3 6 6 4 4.8
Objectives
O4.1 To apply urban scale models with advanced physical and chemical parameterisations in order to more efficiently
describe and assess air quality in megacities
O4.2 To evaluate the performance of the new parameterisations in selected applications
O4.3 To describe and quantify the two-way interaction between megacity air quality and meteorology
O4.4 To assess source contribution in the selected urban areas and suggest recommendations for other cities
O4.5 To use the source apportionment exercise findings in order to identify exposure patterns
Description of work and role of participants
Task 4.1: Multiscale physical processes - From the city to the street scale (lead: AUTH)
Development, implementation and evaluation of a multiscale zooming approach on the basis of the various
parameterisations developed within WP2 with particular focus on physical parameterisations regarding the description
and quantification of pathways of stressors' fate through dispersion, transport and removal processes. The methodology
will be based on the utilisation of ensemble modelling techniques in conjunction with the application of monitoring for
the local ‘hot-spots’ where higher spatial resolution will be required. Several numerical models will be applied
including model coupling, for application at different spatial scales, in order to examine the stressors’ fate across those
scales. In addition to the integration of the physical parameterisations on the meteorological models of different scales
(MEMO, WRF, UM), the effect of these parameterisations on the prediction of the dispersion of pollution and the
resulting concentrations with the use of CTMs (CMAQ, MARS/MUSE) will be studied. The resulting methodology will
be demonstrated and evaluated for selected cities (Paris + 2-3 more conurbations).
Task 4.2: Multiscale chemical processes - From the city to the street scale (lead: FORTH)
Development, implementation and evaluation of a multiscale approach for the description and quantification of the
effective emissions, transformation and removal of pollutants focusing on parameterisations for chemical
transformations. The deviation of the urban from the regional background air pollution will be extensively studied via
the application of various existing CTM’s (MARS/MUSE, PMCAMx, CMAQ, UDM-FMI, UHMA, SALSA, SILAM,
ENVIRO-HIRLAM). The findings will then be used to improve the parameterisations describing the influence of urban
areas on regional scale air quality in WP5.To this end, ensemble modelling techniques in conjunction with laboratory
work within EUCAARI (inorganic aerosol thermodynamics and dynamics, secondary organic formation, etc.) will also
be utilised. In addition, simpler modelling approaches (OFIS, OSCAR system including OSPM, CAR-FMI) will be
applied in order to assess the long-term effects of city plumes on AQ and associated exposure. The resulting
methodology will be demonstrated and evaluated for selected cities (Paris + 2-3 more conurbations).
Task 4.3: Interactions between air quality and meteorology/climate (lead: DMI)
The interaction between megacity air quality and meteorology will be described and quantified. Towards this aim, the
effect of elevated pollutant concentrations on the meteorology as well as the influence of meteorological patterns on
urban air pollution will be studied. In particular, the influence of air pollution on cloud formation, precipitation and
radiation will be assessed and indicators relating meteorological patterns to urban air pollution episodes will be
developed through the application of advanced modelling tools, such as the coupled MEMO /MARS system and the online
coupled environment model DMI-ENVIRO-HIRLAM. The findings will be used in WP8 for risk assessment
closely related to decision and policy making. In addition to the description of the feedback mechanisms directly related
to WP2, this task will assess the indirect effect of urban air pollution on the regional climate which is addressed in WP6.
Task 4.4: Source apportionment – identification and quantification of relevant pathways (lead: AUTH)
Various source apportionment methods will be applied and evaluated with emphasis on the quantification of the
accuracy in identifying the individual contributions of the emission sources. The source apportionment methods will
include innovative combinations of standard receptor modelling techniques and state-of-the-art CTMs. The evaluation
will be based on the experimental results from WP3 and emission data generated in WP1. In addition, monitoring data
from background stations will be utilised and biogenic sources properly assessed with a particular focus on PM and O3.
Findings regarding the contribution of various sources on urban air quality will be used in WP8.
Task 4.5: Exposure estimates (lead: FMI)
Analysis of the role of urban meteorology, land use and urban structure, as well as of the population spatial distribution
and time use on the observed exposure patterns, and development of advanced methods for assessing population
exposure, including literature-based dose/intake estimates. The main aim will be on the evaluation of microenvironment
39