A site selection methodology for CO2 underground storage in deep saline aquifers: case of the Paris Basin

International audienceSite selection is a fundamental step, which can condition the success of a CO2 geological storage. A CO2 storage has to gather several targets, which can be expressed through a list of criteria. In the proposed site selection methodology, these criteria can be classified into “killer criteria” and “site-qualification criteria”, whose combinations allow identifying potential sites and the most appropriate one(s). This multicriteria methodology is applied on the PICOREF study area, located in the Paris Basin, on which potential site(s) in deep saline aquifers are investigated

Narisome muhoko, a citizen science project to monitor the mangroves of Mayotte Island (France) at the time of the initial stages of institutional management

International audienceResearchers in geography and ecology together with an environmentalist association of Mayotte have recently conceived the citizen science project ‘Narisome muhoko’, meaning ‘We study the mangrove’. This project emerged at the end of an interdisciplinary research project on the resilience of two mangrove social-ecological systems (2018-2021) and at the time of the first Mangrove Management Plan (2019-2028) of the island. For each mangrove of Mayotte, the Plan is expected to be enforced by local authorities and/or associations. These stakeholders are particularly struggling with one of the tasks asking to “monitor the evolution of the ecological state and threats” in the absence of any instruction.The ‘Narisome muhoko’ project has two aims: 1. To operationalize this monitoring action by proposing relevant but easy to implement indicators that could be applied by citizens and/or technical agents; 2. To engage Mahore citizens in the management of the mangrove neighbouring their village using these indicators. It is planned to develop a set of indicators aimed at monitoring the evolution of the mangroves health state in response to different environmental pressures. Our experience allowed us to design a project based on the local ecological knowledge of inhabitants (Longépée et al., 2021) in a context where not all citizens have access to recent technologies or is a French speaker. The project first focuses on two mangroves of Mayotte, already studied by the team. In 2022, a team of trained citizens has started monitoring indicators of the phenology of mangrove trees and the regeneration of trees in several areas of the mangrove. At the same time, other indicators will be devised to assess the influence of waste and/or waste water on the mangrove ecosystem and to follow the practise of mangrove tree cutting. This project is in line with the complex systems thinking, aiming to encourage an adaptive management in the spirit of learning-by-doing (Berkes et al., 2003)

Narisome muhoko, a citizen science project to monitor the mangroves of Mayotte Island (France) at the time of the initial stages of institutional management

International audienceResearchers in geography and ecology together with an environmentalist association of Mayotte have recently conceived the citizen science project ‘Narisome muhoko’, meaning ‘We study the mangrove’. This project emerged at the end of an interdisciplinary research project on the resilience of two mangrove social-ecological systems (2018-2021) and at the time of the first Mangrove Management Plan (2019-2028) of the island. For each mangrove of Mayotte, the Plan is expected to be enforced by local authorities and/or associations. These stakeholders are particularly struggling with one of the tasks asking to “monitor the evolution of the ecological state and threats” in the absence of any instruction.The ‘Narisome muhoko’ project has two aims: 1. To operationalize this monitoring action by proposing relevant but easy to implement indicators that could be applied by citizens and/or technical agents; 2. To engage Mahore citizens in the management of the mangrove neighbouring their village using these indicators. It is planned to develop a set of indicators aimed at monitoring the evolution of the mangroves health state in response to different environmental pressures. Our experience allowed us to design a project based on the local ecological knowledge of inhabitants (Longépée et al., 2021) in a context where not all citizens have access to recent technologies or is a French speaker. The project first focuses on two mangroves of Mayotte, already studied by the team. In 2022, a team of trained citizens has started monitoring indicators of the phenology of mangrove trees and the regeneration of trees in several areas of the mangrove. At the same time, other indicators will be devised to assess the influence of waste and/or waste water on the mangrove ecosystem and to follow the practise of mangrove tree cutting. This project is in line with the complex systems thinking, aiming to encourage an adaptive management in the spirit of learning-by-doing (Berkes et al., 2003)

Narisome muhoko, a citizen science project to monitor the mangroves of Mayotte Island (France) at the time of the initial stages of institutional management

International audienceResearchers in geography and ecology together with an environmentalist association of Mayotte have recently conceived the citizen science project ‘Narisome muhoko’, meaning ‘We study the mangrove’. This project emerged at the end of an interdisciplinary research project on the resilience of two mangrove social-ecological systems (2018-2021) and at the time of the first Mangrove Management Plan (2019-2028) of the island. For each mangrove of Mayotte, the Plan is expected to be enforced by local authorities and/or associations. These stakeholders are particularly struggling with one of the tasks asking to “monitor the evolution of the ecological state and threats” in the absence of any instruction.The ‘Narisome muhoko’ project has two aims: 1. To operationalize this monitoring action by proposing relevant but easy to implement indicators that could be applied by citizens and/or technical agents; 2. To engage Mahore citizens in the management of the mangrove neighbouring their village using these indicators. It is planned to develop a set of indicators aimed at monitoring the evolution of the mangroves health state in response to different environmental pressures. Our experience allowed us to design a project based on the local ecological knowledge of inhabitants (Longépée et al., 2021) in a context where not all citizens have access to recent technologies or is a French speaker. The project first focuses on two mangroves of Mayotte, already studied by the team. In 2022, a team of trained citizens has started monitoring indicators of the phenology of mangrove trees and the regeneration of trees in several areas of the mangrove. At the same time, other indicators will be devised to assess the influence of waste and/or waste water on the mangrove ecosystem and to follow the practise of mangrove tree cutting. This project is in line with the complex systems thinking, aiming to encourage an adaptive management in the spirit of learning-by-doing (Berkes et al., 2003)

Gestion des garrigues à chêne kermès sur coupures de combustible

National audienc

Interrelations of the petrophysical, sedimentological and microstructural properties of the Oolithe Blanche Formation (Bathonian, saline aquifer of the Paris Basin)

International audienceThe Paris Basin seems a suitable location for CO2 capture and storage given both the amount of CO2 produced and the availability of depleted fields and deep saline aquifers. This study investigates the petrophysical properties in relation to the sedimentary and diagenetic environment of the Oolithe Blanche Formation (Middle Jurassic), a deep saline aquifer considered a potential candidate for CO2 storage. Because of the scarcity of core data in the Paris Basin, our investigation was based on the study of field analogues in the south-east part of the Paris Basin. The Oolithe Blanche Formation (Bathonian) is 70-80 m thick. Eighteen oriented blocks were collected from three outcrops selected for the different sedimentological facies identified in the formation. Their petrophysical properties were measured: porosity, pore size distribution derived from mercury injection tests, permeability and capillary imbibition parameters. The sedimentary and diagenetic facies were defined by using optical microscopy coupled with image analysis on thin sections and SEM. The Oolithe Blanche Formation is composed of oolitic and bioclastic limestones, deposited in a shallow marine setting. Three main sedimentological facies were defined: the oolitic shoal facies, the tide dominated facies and the prograding oolitic facies. They exhibit subtle variations in composition and in the distribution of carbonate textures. Porosity, measured using the water saturation triple weight method, ranges from 6% to 34%. Permeability values are low, between 0.1 mD and 9 mD. The data from mercury intrusion porosimetry show that the distribution of the pore throat diameter is either unimodal (microporosity only) or bimodal (macro- and microporosity). Microporosity is intraparticle (intraooid) and macroporosity is interparticle and is related to dolo-dedolomitization. Variations of petrophysical parameters can be explained by the microstructure. Now, these latter results calibrated by studying field analogues must be extended to borehole data and core data to optimize our knowledge of the deep saline aquifer of the Oolithe Blanche Formation. Without such investigations, it will be impossible to estimate the suitability of this deep saline aquifer for CO2 storage

LORVER project: production chain of biomass for industrial purposes from former sites and materials

International audienc

A meteorological and chemical overview of the DACCIWA field campaign in West Africa in June–July 2016

International audienceIn June and July 2016 the Dynamics–Aerosol–Chemistry–Cloud Interactions in West Africa (DACCIWA) project organised a major international field campaign in southern West Africa (SWA) including measurements from three inland ground supersites, urban sites in Cotonou and Abidjan, radiosondes and three research aircraft. A significant range of different weather situations was encountered during this period, including the monsoon onset. The purpose of this paper is to characterise the large-scale setting for the campaign as well as synoptic and mesoscale weather systems affecting the study region in the light of existing conceptual ideas, mainly using objective and subjective identification algorithms based on (re-) analysis and satellite products. In addition, it is shown how the described synoptic variations influence the atmospheric composition over SWA through advection of mineral-dust, biomass-burning and urban-pollution plumes. The boreal summer of 2016 was characterised by Pacific La Niña, Atlantic El Niño and warm eastern Mediterranean conditions, whose competing influences on precipitation led to an overall average rainy season. During the relatively dusty pre-onset Phase 1 (1–21 June 2016), three westward propagating coherent cyclonic vortices between 4 and 13° N modulated winds and rainfall in the Guinea coastal area. The monsoon onset occurred in connection with a marked extratropical trough and cold surge over northern Africa, leading to a breakdown of the Saharan heat low and African easterly jet and a suppression of rainfall. During this period, quasi-stationary low-level vortices associated with the trough transformed into more tropical, propagating disturbances resembling an African easterly wave (AEW). To the east of this system, moist southerlies penetrated deep into the continent. The post-onset Phase 2 (22 June–20 July 2016) was characterised by a significant increase of low-level cloudiness, unusually dry conditions and strong northeastward dispersion of urban pollution plumes in SWA as well as rainfall modulation by westward propagating AEWs in the Sahel. Around 12–14 July 2016 an interesting and so-far undocumented cyclonic-anticyclonic vortex couplet crossed SWA. The anticyclonic centre had its origin in the southern hemisphere and transported unusually dry air filled with aged aerosol into the region. During Phase 3 (21–26 July 2016), a similar vortex couplet slightly farther north created enhanced westerly moisture transports into SWA and extraordinarily wet conditions, accompanied by a deep penetration of the biomass-burning plume from central Africa. Finally, a return to more undisturbed monsoon conditions took place during Phase 4 (27–31 July 2016). The in-depth synoptic analysis reveals that several significant weather systems during the DACCIWA campaign cannot be attributed unequivocally to any of the tropical waves and disturbances described in the literature, and thus deserve further study