People

My research focuses on the sources and fate of toxic and climate-active chemicals (e.g., mercury, greenhouse gases, aerosol precursors) using both field observations and modelling tools. I currently investigate how rapid ecosystem changes in the Arctic affect biogeochemical cycles in that region.

Poor air quality is responsible for 7 million premature deaths worldwide, linked to exposure to "fine particles". Air quality regulations are based on particle mass, an incomplete metric for predicting health effects. Oxidizing potential" is seen as a promising metric, and the aim of the ROS-Online project is to develop a device for automated oxidizing potential measurement.

I’m in charge of the technical coordination of the GMOStral research project (instrumental maintenance and development, training and supervision of field staff, logistics, data processing and qualification, etc.). This project, supported by the French Polar Institute IPEV (program #1028, PIs : H. Angot and A. Dommergue) and integrated into the global OBS4CLIM project, has as its main objective the study and monitoring of atmospheric mercury in the French Southern and Antarctic Lands, and more specifically on Amsterdam Island.

I am an environmental engineer and currently PhD student on air pollution at the Institut des Géosciences de l’Environnement (IGE – Université Grenoble Alpes) and Laboratoire de Chimie de l’Environnement (LCE – Aix Marseille Université). I work on the oxidative potential, a proxy for the health impact of airborne particles currently under study in the scientific community. My project aims at investigating the link between oxidative potential and chemical composition of particles, through field analysis in various environments.

As a PhD student at the IGE, I am particularly fascinated by particulate matter sources and their impact on human health. My thesis focuses on the development of methodologies to identify the contributions of emission sources to the chemical composition of atmospheric components. The method developed will be applied to atmospheric particles, ice cores and oxidation potential measured in real time.

For the past 20 years, I have been working on the atmospheric mercury cycle in remote regions, especially in polar regions and high altitude sites. This work is based on long-term observations in exceptional sites like Amsterdam Island or Antarctic bases. I have coordinated several national programs and polar campaigns and participated in many international projects including FP7 GMOS, H2020 ERAPLANET, ITN GMOSTrain. Since 2020, I am director of the Institute of Environmental Geosciences.

My main research interests are associated with the characterisation of organic compounds, their emission sources and physico-chemical processing in the atmosphere. I have implemented various on-line and off-line measurement techniques deployed on the ground and on-board of research aircraft. These techniques allow elucidating the emission sources and the composition of the atmosphere in the gas, aerosol and cloud phases, and the interaction between them. Currently, my research focusses on the chemical characterisation of aerosols, their emission sources, and their potential impacts on atmospheric chemistry and health.

Most of my research work is devoted to analytical developments for chemical measurements in the environment. I first became interested in carbonyl compounds (a class of volatile organic compounds) and applied the methods I developed to understanding the exchange of these compounds between air, snow and cloud water. Today, I’m developing chemical methods designed to measure the capacity of airborne particles (PM) to generate oxidative stress in our bodies. These methods of measuring the "oxidative potential" (OP) of PM are therefore intended to help us better understand the health impact of PM. My teaching focuses mainly on organic/inorganic chemistry and chemistry and air pollution.

My research focuses on estimating people’s exposure to environmental factors such as heat waves, air pollution, and urban structure. The ultimate goal is to understand how those exposures affect health and how urban, suburban, and rural areas can adapt to improve wellbing in the context of climate change and global urbanization. My current project aims to use deep learning to estimate the oxidative potential of ambient particular matter based on satellite images.

I study the exchange of trace compounds between the atmosphere and snow and their influence on the properties and behavior of snow. I am interested in the influence of these trace compounds in snow on climatic, hydrological or biogeochemical processes, mainly in Arctic regions. I am also the PI for the LabEx OSUG entitled Habitability in changing worlds.

The general objectives of my research concern the understanding of the characteristics and sources of atmospheric particles. I develop chemical characterization tools (implementation of new tracers and new measurement methods), as well as appropriate data processing tools. These tools are then applied in numerous applied research projects to various environments.

Paolo Laj is an expert in atmospheric aerosols and specializes in leading European research infrastructures for the atmosphere. He has been involved in the establishment of ACTRIS for more than 20 years. His research focuses on atmospheric composition variability and trends. He currently serves in the GAW/WMO SSC and in the GCOS AOPC panel. Paolo is currently serving as the ACTRIS Scientific Chair and has participated in establishment of the Aerosol, Clouds, and Trace Gases Research Infrastructure (ACTRIS) as a European Research Infrastructure Consortium (ERIC).

The role of aerosols in the Earth’s climate is still poorly quantified, all the more so in the polar regions where observed data are scarce and localized. "Open questions such as "How do aerosols affect polar climate ?" and "What are the contributions of local sources and long-range transport ? Chemistry-transport modelling can provide answers to these questions, but also has shortcomings when it comes to representing certain processes, notably local aerosol emissions of natural origin. The aim of my work is to evaluate and improve the performance of these models in their representation of marine aerosols, in order to better constrain their role in cloud formation in the Arctic and Antarctic.

PhD student at the IGE and the Institute for Advanced Biosciences (IAB, Grenoble), I am particularily interested in the health effects of air pollution. My research focuses on the oxidative potential of particulate matter (PM), the lung function in children from the SEPAGES cohort (https://cohorte-sepages.fr/), and the chemical composition of indoor PM, compared to outdoor PM. This work is funded by ADEME (Climate change - ecological, energy transition) and ANSES (The French Agency for Food, Environmental and Occupational Health & Safety)

I am a communications officer for the CRiceS project, which aims to extend our understanding of climate change, in particular by improving model predictions of the role of polar processes (oceans, ice, snow cover, atmosphere). I participate in the implementation of the communication/dissemination/engagement plan of the project. It aims to increase the visibility of the project, explain it, and share its progress with the target audiences : scientific community, general public, political leaders, indigenous Arctic populations, etc.

My research focuses on using modeling to understand and describe atmospheric chemistry, air quality, and links to climate change. I develop and use 1D chemistry-transport models, 3D regional chemical transport models, meteorological models, and Lagrangian particle dispersion models, with a primary focus on understanding atmospheric chemistry in polar regions of the Earth.

My research domain focuses on atmospheric biogeochemistry, with a specialization in air pollution and its effects on health in urban areas. The core of my research program lies in identifying pollution sources and developing health exposure indicators to predict the harmfulness of aerosols. By examining the composition and properties of aerosols, I aim to understand their sources and mechanisms of formation, as well as their impact on air quality and human well-being. One of the key objectives of my research is to develop reliable indicators of health exposure to assess the potential harm caused by aerosols. These indicators, based on the oxidative potential of aerosols, provide valuable insights into the respiratory effects and associated diseases resulting from exposure to airborne particles. By quantifying and attributing the contribution of different pollution sources to oxidative stress-related health outcomes, we can prioritize mitigation strategies and inform policy decisions aimed at reducing the adverse effects of air pollution on public health. Overall, my research contributes to advancing our understanding of atmospheric biogeochemistry, air pollution, and their impacts on human health in urban settings. By elucidating the relationships between pollution sources, aerosol composition, and health outcomes, I aim to provide scientific evidence that can support effective measures to improve air quality and protect public health in urban areas.

My research has evolved over the years from studying the sources of secondary organic aerosol in the atmosphere, to evaluating the role of aerosol deposition on snow (photo-)chemistry, first in the arctic, and more recently in the Alps. In particular, I collaborate with colleagues from IGE and Meteo-France (CEN) on evaluating the impact of deposited atmospheric dust on snow albedo, and the timing of snow melt. Also deposited with the aerosol are species containing nitrogen, which is a critical nutriment for alpine ecosystems. I collaborate with colleagues from IGE, LECA, and EDyTEM on the Lautaret research platform to provide observational contraints on biogeochemical fluxes (Nitrogen and Carbon) in mountain watershed, focusing on aerosol deposition and surface-atmosphere exchanges. These activities are part of the ICOS-Ecosystem and eLTSER Research Infrastructure.

Most models used to predict Arctic scale or global ozone, largely ignore or include simplified descriptions of halogen chemistry. For example, the current distributed version of the regional Weather Research and Forecasting (WRF) model coupled with Chemistry (WRF-Chem, https://ruc.noaa.gov/wrf/wrf-chem/) does not include a description of halogen chemistry. WRF-Chem is frequently used to study Arctic atmospheric chemistry (e.g. Thomas et al., 2013 ; Thomas et al., 2017 ; Marelle et al., 2017). Inaccurate predictions of boundary layer ozone severely limits our ability to predict Arctic atmospheric chemistry. In addition, we currently do not know how atmospheric chemistry is influenced by the chemical recycling on ice and snow surfaces, which are rapidly changing in a warming Arctic. This PhD will focus on 1D and 3D regional modeling of halogen chemistry in the Arctic, with a focus on improving predictions of boundary layer ozone. This will include identifying the most likely initiating steps for halogen activation, improving the description of heterogeneous halogen recycling in models, and quantifying impacts using well defined model case studies. Work aims to answer the following science : •What are the emissions source regions that contribute to halogen activation and result in ozone depletion events ? •What combinations of bromine and chlorine emissions/recycling on surfaces (sea-ice, snow, aerosols) and atmospheric dynamics result in sustained bromine activation events and ozone depletion ? •What combination of emissions/surface recycling of halogens is needed in a 3D regional model to capture the nature of bromine activation events and their impacts on ozone in the Arctic ?

My research focuses on sources of particulate matter (PM) and oxidative potential (OP) with the aim of identifying precise measures to significantly reduce atmospheric pollution and its health impacts. I try to estimate source contributions through an integrated approach using various modelling techniques, including Positive Matrix Factorization for PM source apportionment, Multiple Linear Regression and Multilayer Perceptron Artificial Neural Network analysis for OP deconvolution. I apply these methods for different environments (indoor/outdoor/ambient) and typologies (urban, rural, traffic, etc.). Finally, I find the associations of exposure to PM and OP with various health endpoints.

My research focuses on mercury transport and transformations in the atmosphere, as well as mercury exchange processes between surfaces, both terrestrial and aquatic, and the atmosphere. To better understand these processes, I combine observations of atmospheric mercury with additional data (e.g. carbon monoxide as a tracer of biomass combustion), modeling techniques and statistical methods.

I am a Research Engineer working on engineering and development works of instrumental and methodological experiments dedicated to atmospheric chemical species studies (gas and particulate phases) from tropical to polar areas, including high altitude sectors. My main expertise is centered on atmospheric cycling of the global contaminant mercury (past, present, future), a related scientific interest in the frame of the Minamata Convention works, even if I am also deeply involved in atmospheric studies dedicated to chemical pollutants. The idea is a better understanding of emission (sources), distribution, deposition (sinks), i.e. behaviour of the different atmospheric compounds studied. To do so, I principally collect and treat in situ data observations collected in remote places. I’m also in charge of the data qualification and management.

The subject of my research are the measurements and source identification of atmospheric pollutants, specifically aerosol particles, based on their physical and chemical properties. My doctoral thesis at IGE ais to characterize the state of air quality in one of the highest metropolitan areas in the world, the conurbation of La Paz-El Alto (Bolivia). It also seeks to identify the main sources of particulate matter (PM) in the same region, using observational data and statistical tools, and to make a first estimate of the effects that these pollution levels have on the health of the inhabitants of these cities.