Publications associées à Carbon monoxide as a tracer of gas transport in snow and other natural porous media

On the importance of the humidity flux for the surface mass balance in the accumulation zone of the Greenland Ice Sheet

It is highly uncertain how the humidity flux between the snow surface and the atmosphere contributes to the surface mass balance (SMB) of the interior Greenland Ice Sheet (GrIS). Due to sparse observations, evaluations of the simulated humidity flux are li ...

Copernicus Gesellschaft Mbh2024

Spatiotemporal Dynamics of Flow and Hydrochemistry in Drainage Networks

Izabela Bujak-Ozga

Despite their high ecological value, non-perennial streams have received less attention than their perennial counterparts. This doctoral thesis addresses this disparity by advancing knowledge on the dynamics of the drainage density and hydrologic processes ...

EPFL2024

Technical note: Two-component electrical-conductivity-based hydrograph separation employing an exponential mixing model (EXPECT) provides reliable high-temporal-resolution young water fraction estimates in three small Swiss catchments

Davide Canone, Jana Freiin von Freyberg

The young water fraction represents the portion of water molecules in a stream that have entered the catchment relatively recently, typically within 2-3 months. It can be reliably estimated in spatially heterogeneous and nonstationary catchments from the a ...

Copernicus Gesellschaft Mbh2024

Assessing sublimation during snow transport and sublimation effects on the isotopic composition of water vapor

Armin Sigmund

Sublimation influences the water storage in snow covers and glaciers, which is important for water use and projections of the sea level rise. Yet, it is challenging to quantify sublimation for large areas or in conditions of snow transport. In-situ measure ...

EPFL2023

Snow Loss Into Leads in Arctic Sea Ice: Minimal in Typical Wintertime Conditions, but High During a Warm and Windy Snowfall Event

Marc Schneebeli Zeugin, Julia Schmale, Markus Frey

The amount of snow on Arctic sea ice impacts the ice mass budget. Wind redistribution of snow into open water in leads is hypothesized to cause significant wintertime snow loss. However, there are no direct measurements of snow loss into Arctic leads. We m ...

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

Spatio-Temporal Dynamics of Snow on Central Arctic Sea Ice and its Implications

David Nicholas Wagner

This thesis presents a comprehensive investigation of the interaction between precipitation and wind-induced erosion and deposition of snow on Arctic sea ice. The study uses observations from the 2019-2020 MOSAiC expedition and makes use of the 3D snow cov ...

EPFL2023

Burst Vision Using Single-Photon Cameras

Edoardo Charbon, Paul Mos, Mohit Gupta

Single-photon avalanche diodes (SPADs) are novel image sensors that record the arrival of individual photons at extremely high temporal resolution. In the past, they were only available as single pixels or small-format arrays, for various active imaging ap ...

IEEE COMPUTER SOC2023

Water vapor transport in snowpacks

Mahdi Jafari

This thesis is an in-depth treatment of water vapor transport in snowpacks and its impacts on snow structure. The aim is to better understand this transport process and to lay the basis for a model representation in physics-based multi-layer snow models. O ...

EPFL2022

Precipitation fate and transport in a Mediterranean catchment through models calibrated on plant and stream water isotope data

Paolo Benettin

To predict hydrologic responses to inputs and perturbations, it is important to understand how precipitation is stored in catchments, released back to the atmosphere via evapotranspiration (ET), or transported to aquifers and streams. We investigated this ...

COPERNICUS GESELLSCHAFT MBH2022

Electron diffraction of deeply supercooled water in no man’s land

Marcel Drabbels, Ulrich Lorenz, Constantin Richard Krüger, Gabriele Bongiovanni, Nathan Junior Mowry

A generally accepted understanding of the anomalous properties of water will only emerge if it becomes possible to systematically characterize water in the deeply supercooled regime, from where the anomalies appear to emanate. This has largely remained elu ...

Nature Research2023

The microbiome of cryospheric ecosystems

Leïla Ezzat, Tom Ian Battin, Hannes Markus Peter, Tyler Joe Kohler, Stylianos Fodelianakis, Massimo Bourquin, Susheel Bhanu Busi, Grégoire Marie Octave Edouard Michoud

The cryosphere includes those parts of Earth where water or soil is frozen, such as snow, ice, glaciers and permafrost soils. Here, the authors present a global inventory of cryospheric microbial communities and their genetic repertoires. ...

Nature Portfolio2022

Rapid Gas Transport from Block-Copolymer Templated Nanoporous Carbon Films

Kumar Varoon Agrawal, Mostapha Dakhchoune, Jing Zhao, Luis Francisco Villalobos Vazquez de la Parra, Kuang-Jung Hsu, Marina Micari, Xuekui Duan

Porous carbon films, attributed to their superior thermal and chemical robustness, are attractive for a number of applications. In the context of molecular separation, a major focus has been on films where the effective pore diameter is lower than 1 nm, e. ...

AMER CHEMICAL SOC2021

Quantitative electronic structure and work-function changes of liquid water induced by solute

Bruno Credidio

Recent advancement in quantitative liquid-jet photoelectron spectroscopy enables the accurate determination of the absolute-scale electronic energetics of liquids and species in solution. The major objective of the present work is the determination of the ...

ROYAL SOC CHEMISTRY2022

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

The Impact of Diffusive Water Vapor Transport on Snow Profiles in Deep and Shallow Snow Covers and on Sea Ice

Michael Lehning, Margaux Caroline Patricia Couttet, Varun Sharma, Nander Wever, Isabelle Amandine Gouttevin, Adrien Michel, Mahdi Jafari

Water vapor transport has been highlighted as a critical process in Arctic snowpacks, shaping the snow cover structure in terms of density, thermal conductivity, and temperature profile among others. Here, we present an attempt to describe the thermally-in ...

2020

Changes in Climatology, Snow Cover, and Ground Temperatures at High Alpine Locations

Michael Lehning

Knowledge about changes in ground temperatures under a changing climate is important for many environmental, economic, and infrastructure applications and can be estimated by transient numerical simulations. However, a full annual cycle of precipitation da ...

2020

Synoptic conditions and atmospheric moisture pathways associated with virga and precipitation over coastal Adelie Land in Antarctica

Alexis Berne, Nicolas Jean François Jullien, Etienne Gabriel Henri Vignon

Precipitation falling over the coastal regions of Antarctica often experiences low-level sublimation within the dry katabatic layer. The amount of water that reaches the ground surface is thereby considerably reduced. This paper investigates the synoptic c ...

2020

Quanta burst photography

Claudio Bruschini, Edoardo Charbon, Arin Can Ülkü, Shantanu Gupta, Mohit Gupta

Single-photon avalanche diodes (SPADs) are an emerging sensor technology capable of detecting individual incident photons, and capturing their time-of-arrival with high timing precision. While these sensors were limited to singlepixel or low-resolution dev ...

2020

Transport and Water Age Dynamics in Soils: A Comparative Study of Spatially Integrated and Spatially Explicit Models

Andrea Rinaldo, Paolo Benettin, Mitra Asadollahi

We address transport by transit times (i.e., the age of water parcels leaving a storage as discharge, deep loss, or evapotranspiration) in subvertical soil systems, key to our understanding of water quality in catchments and streams. While the use of field ...

2020