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

MEGAPOLI 212520
The current state-of-the-art is largely defined by the knowledge and results gained from other
relevant projects addressing the issue of urban AQ assessment and exposure analysis, such as
FUMAPEX, OSCAR, SAPPHIRE, Urban Exposure and BOND. WP4 will build upon this
expertise. We will continue to investigate the role of advanced parameterisations for realistically
describing the physical and chemical processes in the urban atmospheric sublayer, for which a
significant research effort on has been invested in the past for the sake of adjusting the
parameterisation of global and mesoscale NWP models to urban areas. Furthermore, going beyond
this, particular emphasis will be given in the representation of scale interaction processes by the
integration of different scale models (street, local and mesoscale) including the advanced
"urbanised" parameterisations into the modelling tools. The current proposal will also carry forward
the analysis of meteorological patterns leading to urban air pollution episodes conducted, for
example, within FUMAPEX, by the development of suitable indicators linking particular
meteorological conditions/parameters to increased air pollution levels in the urban area. These
indicators will constitute a particularly useful tool for regulators in suggesting effective policies and
mitigation measures. Finally, a combination of modelling and analysis of observations data in WP4
will allow both the quality assurance of the new parameterisations as well as the verification of
input emissions.
To meet the needs of various users, WP4 will lead to a multiscale approach for urban air quality
analyses using advanced modelling tools capable of simulating concentration patterns in megacities.
For this purpose, the contribution of all major pollution sources will be considered, taking into
account various physical and chemical processes which are characteristic for urban environments.
For addressing the aims and objectives of WP4 the following steps will form a suitable
methodology:
• Develop, implement and evaluate a multiscale zooming approach based on the
parameterisations developed in WP2. This will be taken on in two separate tasks, one focused
on advanced physical parameterisations (developed in WP2), and the other on new findings
from chemical laboratory work, as a basis for developing physical and chemical
parameterisations for describing and quantifying pathways of stressors' fate through dispersion,
transformation, transport and removal processes.
• Describe and quantify the feedback interaction between megacity air quality and meteorology,
by investigating the effect of increased pollutant concentrations on the urban meteorology, as
well as the influence of meteorological patterns on air pollution. The effect of specific
meteorological patterns in the development of urban air pollution episodes and the development
of relevant indicators will be investigated. This information can be then used in WP8 for
assessments relevant to policy purposes. Apart from describing feedback mechanisms of direct
relevance to WP2, this task will allow assessing how increased urban scale air pollution
indirectly affects regional climate (relevance to WP6).
• Identify and quantify the impact caused by the main individual local emission sources, including
both mobile and stationary sources. This task will be carried out in cooperation with WP1, as
the appropriate generation of emission data is particularly important in any source
apportionment analysis. The results will reveal which pollution sources are mainly responsible
for poor urban scale air quality, thus being of direct relevance to WP8.
• Analyse and explain the role of urban meteorology, land use and urban structure, and population
spatial distribution and time use on the observed exposure patterns, and develop advanced
methods for producing assessments of both personal and population exposure, and dose/intake
estimates, based on the source apportionment exercise planned in collaboration with WPs 1 and
3. The resulting methodology will be applied in selected target cities, using as input the
computed spatial concentration and population density distributions, as well as the modelling
results from the first tasks.
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