A5087772152- Climate change and permafrost
- Cryospheric studies and observations
- Geology and Paleoclimatology Research
- Methane Hydrates and Related Phenomena
- Arctic and Antarctic ice dynamics
- Indigenous Studies and Ecology
- Geological Studies and Exploration
- Polar Research and Ecology
- Peatlands and Wetlands Ecology
- Arctic and Russian Policy Studies
- Congenital heart defects research
- Groundwater and Isotope Geochemistry
- Mercury impact and mitigation studies
- Geological formations and processes
- Tissue Engineering and Regenerative Medicine
- Aeolian processes and effects
- Case Reports on Hematomas
- Geography Education and Pedagogy
- Diatoms and Algae Research
- Pluripotent Stem Cells Research
- Trauma and Emergency Care Studies
- Congenital Heart Disease Studies
- Inflammatory Biomarkers in Disease Prognosis
- Oil Spill Detection and Mitigation
- Climate Change Communication and Perception
Center for Northern Studies
2014-2024
Université Paris-Saclay
2018-2024
Geosciences Paris-Saclay
2019-2024
Université de Sherbrooke
2021-2024
Centre National de la Recherche Scientifique
2020-2024
Université Laval
2012-2023
Université de Montréal
2015-2023
Alfred-Wegener-Institut Helmholtz-Zentrum für Polar- und Meeresforschung
2023
Institut National de la Recherche Scientifique
2010-2021
Université du Québec à Montréal
2008-2013
Widespread across northern permafrost landscapes, thermokarst ponds and lakes provide vital wildlife habitat play a key role in biogeochemical processes. Stored the sediments of these typically shallow dynamic waterbodies are rich sources paleoenvironmental information whose potential has not yet been fully exploited, likely because concerns over stratigraphic preservation challenges to develop reliable sediment core chronologies. Here, we present an overview recently derived informative...
Abstract Snowmelt is a crucial source of water for many shallow subarctic lakes, but climate models predict that snowfall will decrease in some regions, with profound ecological consequences. Here we use lake isotope data across gradients terrestrial vegetation cover (open tundra to closed forest) and topographic relief identify lakes are vulnerable desiccation under conditions low snowmelt runoff two landscapes—Old Crow Flats, Yukon, Hudson Bay Lowlands, Manitoba (Canada). Lakes located...
Abstract. Ponds and lakes are abundant in Arctic permafrost lowlands. They play an important role wetland ecosystems by regulating carbon, water, energy fluxes providing freshwater habitats. However, ponds, i.e., waterbodies with surface areas smaller than 1. 0 × 104 m2, have not been inventoried on global regional scales. The Permafrost Region Pond Lake (PeRL) database presents the results of a circum-Arctic effort to map ponds from modern (2002–2013) high-resolution aerial satellite...
Abstract The sedimentological and geochemical properties of a 7·47 m long laminated sequence from hypersaline Lake Yoa in northern Chad have been investigated, representing unique, continuous 6100 year continental record climate environmental change the eastern Central Sahara. These data were used to reconstruct Mid Late Holocene history this currently hyper‐arid region, order address question whether transition humid dry Sahara was progressive or abrupt. This study involved suite analyses,...
Although widely distributed throughout Arctic and subarctic regions, thermokarst ponds lakes remain relatively unexplored regarding geomorphological changes in their catchments internal properties relation to climate change over the past decades. This study synthesizes recent landscape evolution modern sedimentology of limnologically diverse near southeastern Hudson Bay, Canada. Spatio-temporal analysis permafrost mounds, ponds, vegetation surface areas five decades revealed that...
Abstract. Ponds and lakes are widespread across the rapidly changing permafrost environments. Aquatic systems play an important role in global biogeochemical cycles, especially greenhouse gas (GHG) exchanges between terrestrial atmosphere. The source, speciation emission rate of carbon released from landscapes strongly influenced by local conditions, hindering pan-Arctic generalizations. This study reports on GHG ages rates aquatic located Bylot Island, continuous zone Eastern Canadian...
Abstract In the ice‐rich permafrost area of Central Yakutia (Eastern Siberia, Russia), climate warming and other natural anthropogenic disturbances have caused degradation soil subsidence, resulting in formation numerous thermokarst (thaw) lakes. These lakes are hotspots greenhouse gas emissions, but with substantial spatial temporal heterogeneity across Arctic. We measured dissolved CO 2 CH 4 concentrations their seasonal patterns over a yearly cycle. Lakes formed Holocene (alas lakes)...
Abstract Lakes and ponds can be hotspots for CO 2 CH 4 emissions, but Arctic studies remain scarce. Here we present diffusive ebullition fluxes collected over several years from 30 lakes formed on an organic‐rich polygonal tundra landscape. Water body morphology strongly affects the mixing regime—and thus seasonal patterns in gas emissions—with ice‐out autumnal turnover periods identified as hot moments most cases. The studied thermokarst lake maintained relatively high rates of...
While the sentinel nature of freshwater systems is now well recognized, widespread integration processes and patterns into our understanding broader climate-driven Arctic terrestrial ecosystem change has been slow. We review current across key responses to climate, which are attributes these with demonstrated sensitive climate forcing. These include ice regimes, temperature thermal structure, river baseflow, lake area water level, permafrost-derived dissolved ions nutrients, carbon...
The hypophosphatemic (Hyp) mouse is a model for human X-linked hypophosphatemia (XLH). To test the hypothesis of an abnormal osteoblast function in XLH, periostea and osteoblasts isolated from normal Hyp mice were transplanted im into mutant mice. thickness osteoid seams at periphery bone nodules volume measured transplants as index formation. Impaired mineralization was evidenced cells by excessive compared with When mice, markedly increased, demonstrating that extracellular environment...
Isolated mouse osteoblasts that retain their osteogenic activity in culture were incubated with [35S] sulfate. Two radiolabeled proteins, addition to proteoglycans, extracted from the calcified matrix of osteoblast cultures. All sulfate label both proteins was form tyrosine as assessed by amino acid analysis and thin layer chromatography following alkaline hydrolysis. The elution behavior on DEAE-Sephacel major sulfated protein apparent Mr sodium dodecyl gels characteristic bone sialoprotein...
[1] Thermokarst (thaw) ponds and lakes are distributed throughout arctic subarctic regions; however their natural variability temporal evolution recorded in the bottom sediments poorly understood. This paper presents a multiproxy study conducted site with many thermokarst near Kuujjuarapik-Whapmagoostui, on eastern shore of Hudson Bay. Sedimentological, geochemical chronological analyses have been performed short sediment cores (10–20 cm) retrieved from limnologically contrasted ponds....
Numerous studies utilizing remote sensing imagery and other methods have documented that thermokarst lakes are undergoing varied hydrological transitions in response to recent climate changes, from surface area expansion drainage evaporative desiccation. Here, we provide a synthesis of conditions for 376 mainly origin across high-latitude North America. We assemble water isotope compositions measured during the past decade at five lake-rich landscapes including Arctic Coastal Plain (Alaska),...
The Hudson Bay Lowlands peatland complex in Canada, the world’s second-largest complex, is experiencing impacts of climate change, potentially threatening its carbon sink capacity; however, direction and magnitude recent changes are uncertain, particularly response to ongoing permafrost thaw, isostatic rebound. In this project, we aim document vegetation (C) storage dynamics, both long- (millennial) short-term (decadal centennial), polygonal peatlands Wapusk National Park (WNP),...
Shallow lakes are common across the Arctic landscape and their ecosystem productivity is often dominated by benthic, cyanobacterial biofilms. Many of these water bodies freeze to bottom biologically inactive during winter, but full freeze-up becoming less with warming. Here we analyzed microbiome structure newly discovered biofilms at deepest site a perennially ice-covered High lake as model polar microbial communities that remain unfrozen throughout year. Biofilms were also sampled from...
Abstract An increased interest in Arctic environments, mainly due to climate change, has changed the conditions for permafrost research recent years. This change been accompanied by a global increase scientific publications, as well trend towards open access publications. We have analyzed abstracts, titles and keywords publications on from 1998 2017 identify developments (topics, impact collaboration) field of light these changes. Furthermore, understand how scientists build are inspired...
Abstract In the ice‐rich permafrost of Arctic regions, thermokarst erosion on slopes induces formation large‐scale retrogressive thaw slumps (RTS). They have significant geomorphological, hydrological, and biogeochemical impacts landscape. Further research is thus needed to better understand respective effect ice content heterogeneities dynamics these erosional features. Here, we present results a full‐scale physical modeling RTS development in cold room. The experimental setup was designed...
The current rate and magnitude of temperature rise in the Arctic are disproportionately high compared to global averages. Along with other natural anthropogenic disturbances, this warming has caused widespread permafrost degradation soil subsidence, resulting formation thermokarst (thaw) lakes areas ice-rich permafrost. These hotspots greenhouse gas emissions (CO2 CH4), but substantial spatial temporal heterogeneity across sub-Arctic regions. In Central Yakutia (Eastern Siberia, Russia),...
Abstract. Accelerating climate change and increased economic environmental interests in permafrost-affected regions have resulted an acute need for more directed permafrost research. In June 2014, 88 early career researchers convened to identify future priorities This multidisciplinary forum concluded that five research topics deserve greatest attention: landscape dynamics, thermal modeling, integration of traditional knowledge, spatial distribution ground ice, engineering issues. These...
A multi-proxy paleolimnological analysis of a sediment core sequence from Lake Malaya Chabyda in Central Yakutia (Eastern Siberia, Russia) was conducted to investigate changes lake processes, including development, and organic carbon accumulation, primary productivity, within the context Late Pleistocene Holocene climate change. Age-depth modeling with 14 C indicates that maximum age is ∼14 cal kBP. Three distinct sedimentary units were identified core. Sedimentological biogeochemical...
Thermokarst ponds are widespread in arctic and subarctic regions, but little is known about their temporal evolution prior to human observations. This paper presents a pioneer biostratigraphic study conducted at site with limnologically contrasted located on the eastern shore of H udson B ay, C anada. Fossil diatom visible near infrared ( VNIR ) derivative spectral analyses were performed short sediment cores, confirming occurrence three distinct stratigraphic facies as already inferred from...
Abstract. Thermokarst lakes are widespread and diverse across permafrost regions, they considered significant contributors to global greenhouse gas emissions. Paleoenvironmental reconstructions documenting the inception development of these ecologically important water bodies generally limited Pleistocene-age deposits Siberia, Alaska, western Canadian Arctic. Here we present gradual transition from syngenetic ice-wedge polygon terrain a thermokarst lake in Holocene sediments eastern We...