The LISA Laboratory
The Inter-universitary Laboratory of Atmospheric Systems (LISA) is a French leading laboratory in the field of atmospheric chemistry and physics comprising around hundred scientists including 67 permanent positions. Continuously appointed by CNRS, the laboratory belong in addition to two different Parisian universities (Paris Diderot University and University Paris-Est at Creteil - UPEC ). The approaches developed at LISA to study atmospheric chemistry, rain chemistry, aerosol chemistry and physics and cultural heritage preservation involve computer simulation, field measurements, satellite measurement, spectroscopy, and experimental simulation.
The MEREIA Group at LISA
The overall scope of the scientific activity of the MEREIA group deals with the understanding of the chemical processes occurring in the troposphere and their consequences on the atmospheric environment.
More precisely, our work is focused on the fate of the tropospheric organic matter (gaseous and particulate) and its impact on air quality, and climate by combining laboratory experiments and field and airborne measurements
In the laboratory, in order to study these phenomena while keeping the experimental conditions controlled, well defined but close as possible from the atmospheric condition, we have adopted the experimental simulation as the base methodology. This approach requires heavily equipped tools: simulation chambers.
On the field, the study the study of the oxidizing photochemical processes rely on the measurement, in various environments, of the low level concentrations of gaseous precursors as well as secondary species such as ozone, volatile organic compounds (VOCs), nitrogen oxides (NOX, NOy…), nitrous acid (HONO), peroxyacetyl nitrate (PAN)…
The research activities of the group are organized into the following topics:
– The oxidizing capacity of the atmosphere;
– The formation and the evolution of atmospheric organic aerosols;
– The atmospheric cycle of VOCs (sources, transport and reactivity);
– The spectroscopy of molecule of atmospheric interest.
The CESAM simulation chamber
The CESAM reactor has been designed to investigate the interactions (exchange, condensation, chemical reactivity, dissolution…) between gas and solid phases. As the radical sources we will be investigated are photo-induced, a great care has be taken with the realism of the irradiation. This device is equipped with up-to-date analytical tools to characterize the chemical and the physical state of gas, aqueous and solid phases. Moreover, this chamber is located in a 170 m2 hall based in the ground floor which enables an easy access for heavy instruments (PTR-MS, AMS, IRMS,…).
One key feature of this chamber is that its versatility enable numerous connections to the chamber for other instruments, making CESAM a good platform for intercalibration campains.
Another key feature is the possibility to generate cloud/fog inside the chamber to study hydrometeores photochemistry or aerosol ageing during avapo-condensation processes.
Furthermore, it is possible to study atmospheric photochemistry at various altitude : Thank to a filter set-up, it is possible to adjust the light source in order to work with solar spectra representatives from ground level to 60 km altitude.
The MILEAGE mobile laboratory
Our Mobile laboratory MILEAGE (MobIle Laboratory for Extensive Gas mEasurements), developed at LISA, allows measurements of atmospheric species at low concentrations and for different weather situation.
This tool was developed to improve our know ledges concerning ozone cycle, atmospheric pollutants measurements in the continental boundary layer.
Mobile MILEAGE allows gas trace measurements at different scales : in urban area (primary pollutants sources); in sub-urban or rural place (secondary compounds), in remote place (background atmosphere composition).
MILEAGE is a Renault Master 3.5t, which has been modified to welcome:
– a Gas-chromatograph (GC) with a flame ionization detector (FID) to measure NMHC (C3-C10);
– a NOx-Toy instrument to measure with the luminol fluorescence techniquesnitrogen species at low concentrations (NO, NO2 and NOy, environmental monitors (Ozone , Nitrogen oxides (NO, NO2), CO…);
– a Weather station (max : 9 m), Photolysis frequencies (JNO2, …);
– A liquid chromatography to measure HONO and HNO3 (NitroMAC);
– An automatic sampler for NMHCs and carbonyl compounds (AMOVOC);
– GC-ECD to detect PeroxyAcetylNitrate (PAN).
Pr. Jean-François Doussin
des Systèmes Atmosphériques (LISA)
Faculté des Sciences
61, avenue du Général De Gaulle
F-94010 Créteil cedex