Masters
The aim of this internship is to contribute to measuring the optical properties of aerosols produced by biomass combustion. These biomass burning aerosols (BBA) are known to be one of the most significant sources of absorbing aerosols in the Earth's atmosphere, making them a key parameter in atmospheric chemistry and the radiation balance. However, their great chemical and microphysical diversity makes them one of the most poorly understood types of aerosols, and very difficult to observe and quantify by remote sensing. In addition, BBA are a major source of uncertainty for chemistry-transport and climate modelling.
You will conduct experiments in the PC2A laboratory to generate particles from 2 phases of biomass combustion: pyrolysis and open combustion. The extinction spectra of these BBA will be recorded using FTIR and UV-visible spectrometers. Simultaneously, the physical properties of these particles will also be studied using particle counters and particle sizers. Chemical analysis will be performed after sampling these BBA on filters. Finaly, the recorded extinction spectra will be processed to retrieve the complex refractive indices (CRI) using a numerical method developed at the LOA. The CRIs of BBA are key parameters from which all optical properties can be derived: absorption coefficient, diffusion coefficient, single scattering albedo, mass absorption coefficient, which are necessary for atmospheric remote sensing and monitoring of biomass fires.
Keywords: Biomass burning aerosols (BBA) - Aerosol metrology - Optical properties - Light scattering and absorption - Fourier transform infrared and UV-visible spectroscopy - Atmospheric remote sensing.
Supervisor: Denis Petitprez (PC2A)
Co-supervisor : Hervé Herbin (LOA)
denis.petitprez@univ-lille.fr Phone: 03 20 43 65 62
herve.herbin@univ-lille.fr
Aerosols play a crucial role in atmospheric processes, influencing climate, air quality, and human health. Understanding their optical properties, especially fluorescence characteristics, is essential for improving remote sensing techniques such as lidar. Fluorescence lidar has emerged as a powerful tool for characterizing aerosol properties, but its interpretation remains challenging due to the complex nature of aerosol fluorescence signatures, which are influenced by particle composition, size, and atmospheric conditions.
This project aims to bridge the gap between laboratory characterization and atmospheric lidar observations by performing controlled fluorescence measurements of aerosols under well-defined conditions. The study will focus on desert dust, bioaerosols and biomass burning aerosols (BBA), using a tunable laser system. These experiments will be performed at the PC2A by using a set-up generating a constant concentration of fine particles in suspension. The flow of particles will be illuminated by a UV-vis light generated by a tunable laser. Fluorescence signals will be recorded by a spectrometer connected to an ICCD camera and photomultiplier. The particle size distribution of the particles will be also recorded in order to link the spectral signature to the concentration and the size of the particles. The results will help to establish a reference database of fluorescence spectra, which will be compared with multispectral fluorescence lidar data obtained from the LOA’s LILAS and LIFE systems. By integrating laboratory measurements with real-world lidar observations, this study aims to enhance the reliability of lidar-based atmospheric monitoring and improve the identification of various aerosol sources in different environmental contexts.
The student will gain hands-on experience in optical spectroscopy, aerosol generation and measurement, fluorescence data acquisition, and data analysis. This multidisciplinary research environment will provide valuable insights into atmospheric sciences, remote sensing technologies, and environmental chemistry.
Keywords: Aerosol metrology - Light scattering and absorption – Fluorescence - LIDAR - Atmospheric remote sensing.
Supervisors: Xavier Mercier (PC2A), Denis Petitprez (PC2A)
Collaborators : Alessandro Faccinetto (PC2A), Philippe Goloub (LOA)
E-mail : denis.petitprez@univ-lille.fr Phone: 03 20 43 65 62
xavier.mercier@univ-lille.fr
To reach the Carbon neutrality target in 2050 as announced Europe in its Green Deal, the electricity demand will be strongly increased for energy, transport and heating/cooling systems. For that, most countries consider clean and renewable energy resources (as wind and solar) as the main energy resources for the future. However, due to their intermittency and the need to keep a secure electricity supply, the energy storage will be an integral part of the modern electricity smart grid. One solution to store the renewable energy excess is what is commonly named ‘electro-fuels’. Hydrogen is often considered as the best candidate but suffers up to now from some drawbacks such as its storage capacity and safety. Another alternative is Ammonia (NH3), which can be considered as a ‘mere’ hydrogen (H2) carrier. Even if these carbon-free fuels are attractive, there are still lot of difficulties to overcome.
Both e-fuels are very attractive in marine transportation, engines and gas turbines applications. Besides their physical chemistry restrictions (such as the low ignition temperature of NH3, or the low density for H2…), the question concerning their pollutant emissions (nitric oxides and N2O) requires still careful attention. To improve the knowledge, pilot laboratory experiments are needed. At the PC2A lab, we are performing species measurements in premixed stabilized flames. The species profiles obtained on a wide range of flame conditions provide an indispensable database for the development of chemical mechanisms representative of NOx formation in flames.
The work program of this Master internship will consist in measuring the species involved in the NH3/H2 blend oxidation in premixed flames. Species will be detected and quantified using spectroscopic laser-based diagnostics (Laser-Induced Fluorescence and absorption), and InfraRed spectroscopy (FTIR). Experimental results will be compared to simulated ones using kinetic modeling tools (ChemkinPro or CANTERA).
Laboratory:
PC2A pc2a.univ-lille.fr
Supervisors: Nathalie Lamoureux, Pascale Desgroux
Contact e-mail: nathalie.lamoureuxuniv-lille.fr, pascale.desgrouxuniv-lille.fr
Title: Atmospheric reactivity of anthracene
Summary:
Polycyclic aromatic hydrocarbons (PAHs) are generated during incomplete combustion processes and are strongly linked to human activities. Many of them are considered potential carcinogens and exhibit toxic as well as mutagenic effects. Their oxidation in the environment often leads to compounds that are more toxic and more water-soluble than the original molecules. Assessing the risks PAHs pose to environmental health therefore requires considering not only their concentrations but also the kinetics of their oxidation reactions. Photodegradation is an important oxidation pathway in the environmental gas phase.
The main goal of this internship is to investigate the atmospheric degradation processes using different theoretical approaches unravelling their most favorable pathways and their atmospheric fate. This work will be conducted in close collaboration with the experimental works performed in the group led by Professor Tara Kahan at the University of Saskatchewan (Canada). This project will be performed within the framework of a larger research program (CPER Ecrin and CDP AREA). The internship will take place at PC2A laboratory, Lille University.
Key words: Atmosphere; Anthracene; Reactivity; Molecular Simulations
* Send to yeny.tobon-correauniv-lille.fr before September 12, 2025