Very dense pollutant emissions over megacities (large urban agglomerations with more than about 7 millions of inhabitants) are strongly affecting air quality on an urban scale and chemical composition on a regional and even global scale. This ultimately affects both public health and regional to global climate. In order to assess the overall effects of megacity emissions, all links between emissions, transport, chemical transformation and deposition processes should be well understood, which is currently not yet true. In particular, despite its adverse effects on health and their climate effect, primary and secondary sources of particulate matter, and in particular of organic aerosol in the urban atmosphere are not well qualified and quantified.
The project MEGAPOLI-PARIS aims at gaining an increasing comprehension of major processes affecting the abundance of particulate matter in a polluted atmosphere, in particular :
· to better assess primary sources of carbonaceous aerosols,
· to better assess secondary sources of organic aerosols through gas-to-particle conversion,
· using this knowledge, to evaluate and improve process and air quality models.
To reach these objectives, an experimental campaign in the Paris agglomeration, a major anthropogenic emission source surrounded by rural areas, will be conducted. State of the art instrumentation will allow documenting the aerosol chemical composition with very high detail and with high temporal resolution, and without artefacts commonly referred to filter sampling. Concurrent measurements of specific emission tracers and of gaseous precursor species will both permit a better quantification of primary and secondary aerosol sources within and in the plume of the agglomeration. These data will enable to evaluate and to improve air quality models which currently do not account properly for carbonaceous formation processes. These models will then be used for source specific scenario simulations, taking into account the European regulation context.
MEGAPOLI is a project for Megacities: Emissions, urban, regional and Global Atmospheric POLlution and climate effects, and Integrated tools for assessment and mitigation.
Objectives of the project lead by many European groups are presented here .
French groups involved in the project presents their contributions here (in French).
Newsletters of the FP7 EC MEGAPOLI Project :
MEGAPOLI-PARIS official site
Communiqué de Presse CNRS : here