Isabelle Coll - Academia.edu (original) (raw)

Papers by Isabelle Coll

Atmospheric environment. X, Apr 1, 2024

Energy-What prospects? Energy transition • Global priority • Environmental policies to reduce GHG... more Energy-What prospects? Energy transition • Global priority • Environmental policies to reduce GHG and air pollutant emissions • Challenge of energy use in the future • Aging population • +10% in 2050 (median scenario) Sustainable Development Scenario • Integrated approach on climate change, air quality and universal access to modern energy. • The compact city New Policies Scenario • Existing energy policies • Announced policy intentions.

Atmospheric Environment

Abstract At a time when many cities are rethinking their development and urban planning policies ... more Abstract At a time when many cities are rethinking their development and urban planning policies in order to cope with new economic, societal and environmental paradigms, the question arises as to which public policies should be favored in order to achieve current and future air quality objectives. Decision support for urban air pollution control can no longer rely solely on improved technologies, but must propose new modelling approaches that integrate urban organization, the individual and energy consumption practices. In this paper, we present the operating principles of the OLYMPUS model and discuss the results obtained during its implementation in two distinct territories. OLYMPUS is an activity-based model that - for a given urban organization - simulates the gaseous and particulate emissions related to the energy consumption of individuals for their mobility, combustion from residential heating, domestic activities and commercial building heating. The very heart of the simulation is to define, prioritize and spatialize the daily mobility of individuals, as well as to define the energy demand per building. The results are presented here for Ile-de-France - a dense metropolis highly served by public transport, housing 12 million inhabitants - and the Pays de la Loire - a polycentric urban area organized around medium-sized towns within a highly rural space. By implementing OLYMPUS on these two different territories, we demonstrate the very good transposability of the tool. In parallel, we propose a discussion of the parameters that most constrain the emissions in the model, and the opportunities for innovative scenarios dedicated to decision support.

According to the WHO, in 2019, 23% of global mortality was attributable to environmental risk fac... more According to the WHO, in 2019, 23% of global mortality was attributable to environmental risk factors with significant gradients related to social factors, at the origin of significant health inequalities in the cities. Air pollution is one main environmental risk in urban spaces, and must therefore also be understood by taking into account the issue of socio-spatial inequalities.Realistic modelling of population exposure to air pollution in large cities requires taking into account air quality at the level of the individual, as well as individual spatial dynamics (mobility and realization of daily activities) that shape each person's risk of exposure. These requirements call for the development of interdisciplinary tools combining the representation of urban space, traffic simulation, emission calculation, advanced air quality models, and the consideration of behavioral and socio-economic dimensions in the modeling process.We present here a socially and spatially differentiated...

Background Mechanisms underlying the associations between changes in the urban environment and ch... more Background Mechanisms underlying the associations between changes in the urban environment and changes in health-related outcomes are complex and their study requires specific approaches. We describe the protocol of the interdisciplinary UrbASanté study, which aims to explore how urban interventions can modify environmental exposures (built, social, and food environments; air quality; noise), health-related behaviors, and self-reported health using a natural experiment approach. Methods The study is based on a natural experiment design using a before/after protocol with a control group to assess changes in environmental exposures, health-risk behaviors, and self-reported health outcomes of a resident adult population before and after the implementation of a time series of urban interventions in four contiguous neighborhoods in Paris (France). The changes in environmental exposures, health-related behaviors, and self-reported health outcomes of a resident adult population will be con...

EGU General Assembly Conference Abstracts, Apr 1, 2019

Organic aerosol (OA) still remains one of the most difficult components of the atmospheric aeroso... more Organic aerosol (OA) still remains one of the most difficult components of the atmospheric aerosols to simulate, given the multitude of its precursors, the uncertainty of its formation pathways and the lack of measurements of its detailed composition. The LANDEX project (The LANDes Experiment), during its intensive field campaign in summer 2017, gives us not only the opportunity to compare biogenic secondary OA (BSOA), but also its precursors and oxidants obtained within and above the Landes forest canopy, to simulations performed with CHIMERE, a state of the art regional Chemistry-Transport Model. The Landes forest is situated in the southwestern part of France, and is one of the largest anthropized forests in Europe (1 million ha), composed by a majority of maritime pine trees, strong terpenoid emitters, providing a large potential for biogenic SOA formation. In order to simulate OA build-up in this area, a specific model configuration setup , adapted to the local peculiarities was necessary. As the forest is inhomogeneous, with interstitial agricultural fields, high-resolution 1 km simulations over the forest area were performed. BV OC emissions were predicted by MEGAN, but specific land cover information needed to be used, chosen from the comparison of several high-resolution land cover databases. Moreover, the tree species distribution needed to be updated for the specific conditions of the Landes forest. In order to understand the canopy effect in the forest, canopy effects on vertical diffusivity, winds and radiation were implemented in the model in a simplified way. The refined simulations show a redistribution of BV OCs with a decrease in isoprene and an increase in terpenoid emissions with respect to the standard case, in line with observations. Corresponding changes on simulated BSOA sources are tracked. Very low night-time ozone, sometimes near zero, remains overestimated in all simulations. This has implications to the night-time oxidant budget, including NO 3. Despite careful treatment of physical conditions, simulated BSOA is overestimated in the most refined simulation. Simulations are also compared to air quality sites surrounding the Landes forest, reporting a more realistic simulation in these stations in the most refined test case. Finally the importance of the see breeze system which also impacts species concentrations inside the forest is made evident.

Atmospheric Chemistry and Physics, Apr 5, 2019

HAL (Le Centre pour la Communication Scientifique Directe), May 3, 2007

De nos jours, les phénomènes menant à la production photochimique d'ozone sont bien compris et co... more De nos jours, les phénomènes menant à la production photochimique d'ozone sont bien compris et correctement reproduits par les modèles eulériens de chimie-transport. Néanmoins, l'interaction des échelles de production et de transport d'ozone rend très complexe la maîtrise des concentrations d'ozone au-dessus des continents urbanisés, en particulier en été lors des périodes de forte chaleur et de vents faibles. Ce document présente les principaux volets de l'étude du comportement de l'ozone en fonction des émissions de ses précurseurs, ou comment concevoir les actions à mettre en oeuvre aux différentes échelles d'espace et de temps pour maîtriser la pollution photochimique.

HAL (Le Centre pour la Communication Scientifique Directe), May 24, 2006

Afin de réduire les concentrations d'ozone dans la troposphère, la communauté européenne a instau... more Afin de réduire les concentrations d'ozone dans la troposphère, la communauté européenne a instauré une politique environnementale basée sur le contrôle des émissions des précurseurs d'ozone. L'étude présentée ici est consacrée à évaluer l'efficacité des mesures engagées, à l'aide d'un outil devenu aujourd'hui incontournable pour l'analyse des épisodes de pollution photochimique : la modélisation.

The simulation of fine organic aerosols with CTMs (Chemistry Transport Models) in the western Med... more The simulation of fine organic aerosols with CTMs (Chemistry Transport Models) in the western Mediterranean basin has not been studied until recently. The ChArMEx (the Chemistry-Aerosol Mediterranean Experiment) SOP 2 (Special Observation Period 2) intensive field campaign in summer of 2013 gathered a large and comprehensive dataset of observations allowing the study of different aspects of the Mediterranean atmosphere including the formation of organic aerosols (OA) in 3D models. In this study, we used the CHIMERE CTM to perform simulations for the duration of the SAFMED (Secondary Aerosol Formation in the MEDiterranean) period (July to August 2013) of this campaign. In particular, we evaluated four schemes for the simulation of OA, including the CHIMERE standard scheme, the VBS (Volatility Basis Set) standard scheme with two parameterizations including aging of biogenic secondary OA, and a modified version of the VBS scheme which includes fragmentation and formation of non-volatile OA. The results for these four schemes are compared to observations at two stations in the western Mediterranean basin, located in Cap Corse (Corsica) and Cap Es Pinar (Mallorca). These observations include OA mass concentration, PMF (positive matrix factorization) results of different OA fractions, and 14 C observations showing the fossil or non-fossil origins of carbonaceous particles. It is concluded that the modified VBS scheme is close to observations in all three aspects mentioned above; the standard VBS scheme without BSOA (Biogenic Secondary Organic Aerosol) aging also has a satisfactory performance in simulating the mass concentration of OA, but not for the source origin analysis comparisons. In addition, the OA sources over the western Mediterranean basin are explored. OA shows a major biogenic origin,

The gaseous VOC precursors for organic aerosol (OA) formation in different chemical schemes used ... more The gaseous VOC precursors for organic aerosol (OA) formation in different chemical schemes used in this work are presented in table SI-1. Species with an L after their name are lumped species, meaning that they are surrogates for a group of species; in this case, a representative compound is given in the table. Note that the precursors for both the standard VBS schemes (with and without BSOA aging) and modified VBS scheme are the same.

Journal of Geophysical Research: Atmospheres, 2007

In the French Mediterranean basin the large city of Marseille and its industrialized suburbs (oil... more In the French Mediterranean basin the large city of Marseille and its industrialized suburbs (oil plants in the Fos‐Berre area) are major pollutant sources that cause frequent and hazardous pollution episodes, especially in summer when intense solar heating enhances the photochemical activity and when the sea breeze circulation redistributes pollutants farther north in the countryside. This paper summarizes the findings of 5 years of research on the sea breeze in southern France and related mesoscale transport and dilution of pollutants within the Field Experiment to Constraint Models of Atmospheric Pollution and Emissions Transport (ESCOMPTE) program held in June and July 2001. This paper provides an overview of the experimental and numerical challenges identified before the ESCOMPTE field experiment and summarizes the key findings made in observation, simulation, and theory. We specifically address the role of large‐scale atmospheric circulation to local ozone vertical distributio...

Advances in Science and Research, 2010

The EU FP7 Project MEGAPOLI: "Megacities: Emissions, urban, regional and Global Atmospheric POLlu... more The EU FP7 Project MEGAPOLI: "Megacities: Emissions, urban, regional and Global Atmospheric POLlution and climate effects, and Integrated tools for assessment and mitigation" (http://megapoli. info) brings together leading European research groups, state-of-the-art scientific tools and key players from non-European countries to investigate the interactions among megacities, air quality and climate. MEGAPOLI bridges the spatial and temporal scales that connect local emissions, air quality and weather with global atmospheric chemistry and climate. The suggested concept of multi-scale integrated modelling of megacity impact on air quality and climate and vice versa is discussed in the paper. It requires considering different spatial and temporal dimensions: time scales from seconds and hours (to understand the interaction mechanisms) up to years and decades (to consider the climate effects); spatial resolutions: with model down-and up-scaling from street-to global-scale; and two-way interactions between meteorological and chemical processes.

Figure SI1: Domains used in the study: 1: European coarse domain (25kmx25km horizontal resolution... more Figure SI1: Domains used in the study: 1: European coarse domain (25kmx25km horizontal resolution), 2: French intermediate domain (5kmx5km horizontal resolution) and 3: high-resolution domain (1kmx1km horizontal resolution. © OpenStreetMap contributors 2022. Distributed under the Open Data Commons Open Database License (ODbL) v1.0.