Publications associées à Silicon isotopes in Arctic and sub-Arctic glacial meltwaters: the role of subglacial weathering in the silicon cycle

The microbial genomics of glacier-fed streams: adaptations to an extreme ecosystem

Glacier-fed streams are the cold, ultra-oligotrophic, and unstable streams that are fed by glacial meltwater. Despite these extreme conditions, they harbour a diverse and abundant microbial diversity that develops into biofilms, covering the boulders and s ...

EPFL2024

Atmospheric isoprene measurements reveal larger-than-expected Southern Ocean emissions

Julia Schmale, Andrea Baccarini

Isoprene is a key trace component of the atmosphere emitted by vegetation and other organisms. It is highly reactive and can impact atmospheric composition and climate by affecting the greenhouse gases ozone and methane and secondary organic aerosol format ...

Nature Research2024

Global emergent responses of stream microbial metabolism to glacier shrinkage

Nicola Deluigi, Tom Ian Battin, Hannes Markus Peter, Michail Styllas, Tyler Joe Kohler, Massimo Bourquin

Most cryospheric ecosystems are energy limited. How their energetics will respond to climate change remains largely unknown. This is particularly true for glacier-fed streams, which interface with the cryosphere and initiate some of Earth's largest river s ...

Nature Portfolio2024

Diagenetic isotope exchange in biocalcites for paleoclimate reconstruction

Deyanira Graciela Cisneros Lazaro

The oxygen isotope compositions of fossil biocalcites, such as foraminifera, bivalves, brachiopods, and belemnites have allowed for reconstructions of sea surface and deep ocean temperatures throughout the Phanerozoic and constitute the most important reco ...

EPFL2024

The cost of adaptability: resource availability constrains functional stability under pulsed disturbances

Hannes Markus Peter

Global change exposes ecosystems to changes in the frequency, magnitude, and concomitancy of disturbances, which impact the composition and functioning of these systems. Here, we experimentally evaluate the effects of salinity disturbances and eutrophicati ...

Amer Soc Microbiology2024

Combined Earth observations reveal the sequence of conditions leading to a large algal bloom in Lake Geneva

Damien Bouffard, Abolfazl Irani Rahaghi, Marco Toffolon, Oscar Rodrigo Sepúlveda Steiner, Rafael Sebastian Reiss, Frédéric Charles Soulignac

Freshwater algae exhibit complex dynamics, particularly in meso-oligotrophic lakes with sudden and dramatic increases in algal biomass following long periods of low background concentration. While the fundamental prerequisites for algal blooms, namely ligh ...

Springernature2024

The biofilm ecology of proglacial floodplain streams

Jade Brandani

Glacial forelands figure among the most dynamic landscapes on Earth, and their formation is currently accelerating given glacier shrinkage. Draining these forelands are streams hosting unique microbial communities, which have the capacity to impact both th ...

EPFL2023

Ecosystem engineering by periphyton in Alpine proglacial streams

Matteo Roncoroni, Tom Ian Battin, Marc Aguet, Adrijan Selitaj, Davide Mancini

Stream periphytons are candidate ecosystem engineers in proglacial margins. Here, we quantify the extent to which they are engineers for the case of hillslope-fed tributaries in the terrace zones of proglacial margin alluvial plains. Candidate ecosystem en ...

WILEY2023

Near-bed stratification controls bottom hypoxia in ice-covered alpine lakes

Damien Bouffard, Pascal Perolo, Tomy Doda, Nicolas Thomas Georges Escoffier, Janine Rüegg, Hannah Elisa Chmiel, Hugo Nicolás Ulloa Sánchez, Camille Roland Marie Minaudo

In ice-covered lakes, near-bottom oxygen concentration decreases for most of the wintertime, sometimes down to the point that bottom waters become hypoxic. Studies insofar have reached divergent conclusions on whether climate change limits or reinforces th ...

American Society of Limnology and Oceanography2023

Polar oceans and sea ice in a changing climate

Jenny Thomas, Julia Schmale, Hélène Paule Angot

Polar oceans and sea ice cover 15% of the Earth’s ocean surface, and the environment is changing rapidly at both poles. Improving knowledge on the interactions between the atmospheric and oceanic realms in the polar regions, a Surface Ocean–Lower Atmospher ...

2023

A Case Study on Drivers of the Isotopic Composition of Water Vapor at the Coast of East Antarctica

Michael Lehning, Armin Sigmund, Riqo Chaar

Stable water isotopes (SWIs) contain valuable information on the past climate and phase changes in the hydrologic cycle. Recently, vapor measurements in the polar regions have provided new insights into the effects of snow-related and atmospheric processes ...

AMER GEOPHYSICAL UNION2023

Excess labile carbon promotes diazotroph abundance in heat-stressed octocorals

Claudia Isabella Pogoreutz

Nitrogen limitation is the foundation of stable coral-algal symbioses. Diazotrophs, prokaryotes capable of fixing N-2 into ammonia, support the productivity of corals in oligotrophic waters, but could contribute to the destabilization of holobiont function ...

ROYAL SOC2023

Southern Hemisphere atmospheric history of carbon monoxide over the late Holocene reconstructed from multiple Antarctic ice archives

Jérôme Chappellaz

Carbon monoxide (CO) is a naturally occurring atmospheric trace gas, a regulated pollutant, and one of the main components determining the oxidative capacity of the atmosphere. Evaluating climate–chemistry models under different conditions than today and c ...

2023

Untangling the influence of Antarctic and Southern Ocean life on clouds

Jenny Thomas, Julia Schmale, Hélène Paule Angot, Markus Frey

Polar environments are among the fastest changing regions on the planet. It is a crucial time to make significant improvements in our understanding of how ocean and ice biogeochemical processes are linked with the atmosphere. This is especially true over A ...

2023

Snow-Atmosphere Humidity Exchange at the Ice Sheet Surface Alters Annual Mean Climate Signals in Ice Core Records

Sonja Wahl

Surface processes alter the water stable isotope signal of the surface snow after deposition. However, it remains an open question to which extent surface post-depositional processes should be considered when inferring past climate information from ice cor ...

Amer Geophysical Union2023

What happens to biomass burning-emitted particles in the ocean? A laboratory experimental approach based on their tracers

Christos Panagiotopoulos

Wildfires, controlled burns, and biofuel combustion (biomass burning or BB) are major contributors to particulate matter in the atmosphere and thus have an impact on climate, human health, and ecosystems. Once emitted, the particulate matter derived from B ...

Elsevier2023

Metabolism of the symbiotic jellyfish Cassiopea in a changing environment

Gaëlle Delphine Toullec

Ocean warming and other anthropogenic impacts have led to a global decline in many photosymbiotic cnidarians, most notably reef-building corals. But some species of the symbiotic and (sub-)tropical upside-down jellyfish Cassiopea are increasingly reported ...

EPFL2023

Multi-campaign ship and aircraft observations of marine cloud condensation nuclei and droplet concentrations

Jian Wang, Athanasios Nenes

In-situ marine cloud droplet number concentrations (CDNCs), cloud condensation nuclei (CCN), and CCN proxies, based on particle sizes and optical properties, are accumulated from seven field campaigns: ACTIVATE; NAAMES; CAMP(2)EX; ORACLES; SOCRATES; MARCUS ...

NATURE PORTFOLIO2023

River ecosystem metabolism and carbon biogeochemistry in a changing world

Enrico Bertuzzo, Tom Ian Battin, Luis Gómez Gener

River networks represent the largest biogeochemical nexus between the continents, ocean and atmosphere. Our current understanding of the role of rivers in the global carbon cycle remains limited, which makes it difficult to predict how global change may al ...

NATURE PORTFOLIO2023

Coupled carbon and nitrogen cycling regulates the cnidarian–algal symbiosis

Anders Meibom, Stéphane Laurent Escrig, Nils Rädecker

Efficient nutrient recycling underpins the ecological success of cnidarian-algal symbioses in oligotrophic waters. In these symbioses, nitrogen limitation restricts the growth of algal endosymbionts in hospite and stimulates their release of photosynthates ...

Nature Research2023