Publications associées à Atlantic meridional overturning circulation

A seasonal snowpack model forced with dynamically downscaled forcing data resolves hydrologically relevant accumulation patterns

Michael Lehning, Dylan Stewart Reynolds, Tobias Jonas

The Mountain snowpack stores months of winter precipitation at high elevations, supplying snowmelt to lowland areas in drier seasons for agriculture and human consumption worldwide. Accurate seasonal predictions of the snowpack are thus of great importance ...

Frontiers Media Sa2024

Lake surface cooling drives littoral-pelagic exchange of dissolved gases

Alfred Johny Wüest, Damien Bouffard, Tomy Doda, Hugo Nicolás Ulloa Sánchez, Cintia Luz Ramon Casanas

The extent of littoral influence on lake gas dynamics remains debated in the aquatic science community due to the lack of direct quantification of lateral gas transport. The prevalent assumption of diffusive horizontal transport in gas budgets fails to exp ...

Amer Assoc Advancement Science2024

Good enough: Intermediate complexity atmospheric models improve the representation of processes affecting seasonal snow

Dylan Stewart Reynolds

Snow plays a crucial role in processes regulating ecosystems, the climate, and human development. Mountain snowpack in particular has great relevance for downstream communities. Knowledge about the distribution and properties of the snowpack thus help in p ...

EPFL2024

A 2000-year temperature reconstruction on the East Antarctic plateau from argon-nitrogen and water stable isotopes in the Aurora Basin North ice core

Jérôme Chappellaz

The temperature of the Earth is one of the most important climate parameters. Proxy records of past climate changes, in particular temperature, represent a fundamental tool for exploring internal climate processes and natural climate forcings. Despite the ...

COPERNICUS GESELLSCHAFT MBH2023

Density currents driven by differential cooling in lakes: occurrence, dynamics and implications for littoral-pelagic exchange

Tomy Doda

Cross-shore flows exchange water laterally in lakes, with ecological implications for the ecosystem. One example is the convective circulation induced by differential cooling, also known as the thermal siphon. This lateral flow forms when the sloping sides ...

EPFL2022

Wind‐Induced Hypolimnetic Upwelling Between the Multi‐Depth Basins of Lake Geneva During Winter: An Overlooked Deepwater Renewal Mechanism?

David Andrew Barry, Ulrich Lemmin, Rafael Sebastian Reiss

Combining field observations, 3D hydrodynamic modeling, and particle tracking, we investigated wind-induced interbasin exchange between the Petit Lac (PL) (depth 75 m) and Grand Lac (GL) (depth 309 m) basins of Lake Geneva in early winter. Following a stro ...

2022

Basin-scale gyres and mesoscale eddies in large lakes: A novel procedure for their detection and characterization, assessed in Lake Geneva

David Andrew Barry, Ulrich Lemmin, Seyed Mahmood Hamze Ziabari, Frédéric Charles Soulignac, Mehrshad Foroughan

In large lakes subject to the Coriolis force, basin-scale gyres and mesoscale eddies, i.e. rotating coherent water masses, play a key role in spreading biochemical materials and energy throughout the lake. In order to assess the spatial and temporal extent ...

2022

Dynamics of wind-induced coastal upwelling and interbasin exchange in Lake Geneva during winter: Implications for deepwater renewal

Rafael Sebastian Reiss

Water quality in lakes is closely linked to hydrodynamics and often dominated by stratification, limiting the exchange between the epi- and hypolimnion. Thus, the vertical redistribution of biogeochemical tracers such as dissolved oxygen and nutrients by c ...

EPFL2021

Moored observations of turbulent mixing events in deep Lake Garda, Italy

Sebastiano Piccolroaz, Marco Toffolon

Deep water circulation and mixing processes are responsible for the transport of matter, nutrients and pollutants in deep lakes. Nevertheless, detailed continuous observations are rarely available. To overcome some of these deficiencies and with the aim of ...

2021

The role of air-sea fluxes for the water vapour isotope signals in the cold and warm sectors of extratropical cyclones over the Southern Ocean

Josué Etienne Gehring, Irina Gorodetskaya

Meridional atmospheric transport is an important process in the climate system and has implications for the availability of heat and moisture at high latitudes. Near-surface cold and warm temperature advection over the ocean in the context of extratropical ...

Copernicus Gesellschaft Mbh2021

Snapshots of mean ocean temperature over the last 700,000 yr using noble gases in the EPICA Dome C ice core

Adrien Michel

Together with the latent heat stored in glacial ice sheets the ocean heat uptake carries the lion’s share of glacial/interglacial changes in the planetary heat content but little direct information on the global mean ocean temperature (MOT) is available to ...

2021

Microphysics and dynamics of snowfall associated with a warm conveyor belt over Korea

Alexis Berne, Josué Etienne Gehring, Nikola Besic, Etienne Gabriel Henri Vignon, Nicolas Jean François Jullien

On 28 February 2018, 57mm of precipitation associated with a warm conveyor belt (WCB) fell within 21 h over South Korea. To investigate how the large-scale circulation influenced the microphysics of this intense precipitation event, we used radar measureme ...

Copernicus Publications2020

Dissolved Organic Nitrogen Production and Export by Meridional Overturning in the Eastern Subpolar North Atlantic

Bieito Fernandez Castro

Dissolved organic matter (DOM) is produced in the surface and exported towards the deep ocean, adding similar to 2 PgC/year to the global carbon export. Due to its central role in the Meridional Overturning Circulation, the eastern subpolar North Atlantic ...

2019

Characterisation of the melting layer variability in an Alpine valley based on polarimetric X-band radar scans

Alexis Berne, Floortje Elisabeth Maria Van den Heuvel, Marco Gabella, Urs Martin Germann

The melting layer designates the transition region from solid to liquid precipitation, and is a typical feature of the vertical structure of stratiform precipitation. As it is characterised by a well-known signature in polarimetric radar variables, it can ...

COPERNICUS GESELLSCHAFT MBH2018

Evaluation of the CloudSat surface snowfall product over Antarctica using ground-based precipitation radars

Alexis Berne, Jacopo Grazioli

In situ observations of snowfall over the Antarctic Ice Sheet are scarce. Currently, continent-wide assessments of snowfall are limited to information from the Cloud Profiling Radar on board the CloudSat satellite, which has not been evaluated up to now. I ...

COPERNICUS GESELLSCHAFT MBH2018

Attenuation of wind-induced pressure perturbations in alpine snow

Wolf Hendrik Huwald, Marc Parlange, Chad Higgins

Windpumping has been identified as a process that could potentially enhance sublimation of surface snow at high forcing frequency and spawn air movement deeper in firn at lower frequencies. We performed an experiment to examine the relationship between hig ...

International Glaciological Society2016

Simulating ice layer formation under the presence of preferential flow in layered snowpacks

Michael Lehning, Nander Wever, Sebastian Würzer, Charles Fierz

For physics-based snow cover models, simulating the formation of dense ice layers inside the snowpack has been a long-time challenge. Their formation is considered to be tightly coupled to the presence of preferential flow, which is assumed to happen throu ...

Copernicus GmbH2016