Research partners in the campaign include:

• LISA/IPSL (CNRS / Universités Paris-Est et Paris 7)
• LSCE/IPSL (CEA / CNRS / UVSQ)
• GAME-CNRM (Météo-France / CNRS
• LaMP (CNRS / Université Blaise Pascal
• LCME (Université de Savoie
• LCP-IRA (CNRS / Université de Provence
• LGGE (Université Joseph Fourier / CNRS)
• SAFIRE (CNRS / Météo-France / CNES)
• AIRPARIF
• INERIS
• LATMOS/IPSL (CNRS / UVSQ / UPMC
• LMD/IPSL (CNRS / ENS / Ecole Polytechnique / UPMC
• CEREA (Ecole des Ponts et Chaussés / EDF
• le Département Chimie & Environnement (Ecole des Mines de Douai)
• Institut für Troposphärenforschung, Leipzig, Germany
• Paul Scherer Institut, Villingen, Switzerland
• Université de Patras, Greece
• Université d'Helsinki, Finland
• Max-Planck Institut für Chemie à Mayance, Germany
• Université Essen-Duisburg, Germany

The campaign is being carried out as part of the EU-funded MEGAPOLI (Megacities: emissions, urban, regional and global atmospheric pollution and climate effects, and integrated tools for assessment and mitigation) project. With €3.4 million (US$4.8 million) in funding, MEGAPOLI is supported under the Environment (including climate change) Theme of the Seventh Framework Programme (FP7).

MEGAPOLI is coordinated by the Danish Meteorological Institute (DMI) and involves 22 partners from 12 European countries including the Czech Republic, France, Greece, Italy, Switzerland and the UK.

The researchers from two laboratories operated by L’Institut national des sciences de l’Univers (INSU) and Centre National de la Recherche Scientifique (CNRS) say large conurbations (metropolitan areas) are being affected by particulate pollution, with air quality and human health bearing the brunt of the problem. Particulate pollution also impacts the climate on global and regional fronts.

But the challenge is determining and quantifying the sources of carbon particulates, which make up a large fraction of fine aerosols.

The project partners describe both primary and secondary sources. Primary sources are direct emissions, generated by combustion processes that are not well quantified; secondary sources are particulates formed after the oxidation and condensation of initially volatile organic compounds.

The researchers selected Île-de-France as the location for the study because it has a rather high pollution load and a high population density; it also exemplifies conurbations in the temperate latitudes.

Various tools are being used to obtain a wide spectrum of data. Ground-based observations are being carried out at three sites, including the Paris Hygiene Laboratory. Also, researchers based at SIRTA (Site Instrumental de Recherche par Télédétection Atmosphérique) of Institut Pierre Simon Laplace (IPSL) are sampling air masses exposed to pollution in the Paris conurbation.

The researchers are also making use of mobile monitoring: vans will carry equipment that can measure the extent of the pollution plume (degraded water in streams or aquifers) in several locations throughout the region and determine the pollution load of air masses entering Île-de-France.

Airborne observations are also being conducted to assess how secondary organic aerosols (suspensions of fine particles in the atmosphere) are formed in the urban plume, and a tethered balloon will be used to evaluate the vertical homogeneity of the pollution.

With this barrage of tools and instruments, the researchers will be able to secure a detailed physical and chemical characterization of particulate pollution (such as volatility and the size distribution of aerosols) in one of the region’s most important metropolitan areas. The results of the study will enable researchers to further assess and revamp existing models used for forecasting and simulation of air pollution in the short and long terms.

The researchers expect to launch another field campaign in late 2009, early 2010. Participating in the study are researchers from Finland, France, Germany, Greece and Switzerland.