Publications associées à Réanalyse météorologique

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

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

Assessing the simulation of snowfall at Dumont d'Urville, Antarctica, during the YOPP-SH special observing campaign

Alexis Berne, Etienne Gabriel Henri Vignon

The performance of a set of atmospheric models and meteorological reanalyses in the representation of precipitation days in Antarctica is assessed using ground-based observations such as a precipitation gauge and a Micro Rain Radar during the Year Of Polar ...

WILEY2023

Present and Future of Rainfall in Antarctica

Alexis Berne, Etienne Gabriel Henri Vignon

While most precipitation in Antarctica falls as snow, little is known about liquid precipitation, although it can have ecological and climatic impacts. This study combines meteorological reports at 10 stations with the ERA5 reanalysis to provide a climatol ...

AMER GEOPHYSICAL UNION2021

Stochastic Super-Resolution for Downscaling Time-Evolving Atmospheric Fields With a Generative Adversarial Network

Alexis Berne, Jussi Sakari Leinonen, Daniele Nerini

Generative adversarial networks (GANs) have been recently adopted for super-resolution, an application closely related to what is referred to as "downscaling'' in the atmospheric sciences: improving the spatial resolution of low-resolution images. The abil ...

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

Application of an Ensemble Kalman filter to a semi-distributed hydrological flood forecasting system in alpine catchments

Giovanni De Cesare, Javier García Hernández, Alain Tommy Foehn, Anne Schwob

One of the key success factor for hydrological forecasts is the establishment of initial conditions that represent well the conditions of the simulated basin at the beginning of the forecast. Real-time Data Assimilation (DA) has been shown to allow improvi ...

2019

A polarimetric radar operator to evaluate precipitation from the COSMO atmospheric model

Daniel Wolfensberger

Weather radars provide real-time measurements of precipitation at a high temporal and spatial resolution and over a large domain. A drawback, however, it that these measurements are indirect and require careful interpretation to yield relevant information ...

EPFL2018

Evaluation of modelled snow depth and snow water equivalent at three contrasting sites in Switzerland using SNOWPACK simulations driven by different meteorological data input

Michael Lehning, Charles Fierz

The knowledge of certain snow indices such as the number of snow days, maximum snow depth and snow water equivalent or the date of snow disappearance is important for many economical and ecological applications. However, snow data are frequently not availa ...

Elsevier2014

HYMEX-SOPI The Field Campaign Dedicated to Heavy Precipitation and Flash Flooding in the Northwestern Mediterranean

Alexis Berne

The Mediterranean region is frequently affected by heavy precipitation events associated with flash floods, landslides, and mudslides that cause hundreds of millions of euros in damages per year and, often, casualties. A major field campaign was devoted to ...

American Meteorological Society2014

Understanding Small Scale Variability of the Mountain Snow Cover

In mountains the snow cover is heterogeneously distributed in space and time. The spatial and temporal variability of the Alpine snow cover has a major influence on avalanche danger, snow hydrology, mountain ecology and winter tourism. In winter, already d ...

EPFL2011

Génération multi-sites de variables météorologiques horaires en zone alpine : application à la simulation de scénarios de crues du Rhône supérieur suisse

Abdelkader Mezghani

Water resources management and hydrological risks are based, to a large extent, on our competence to generate relevant hydrological scenarios under present and future climatic situations. In alpine areas, characterized by highly complex topography, the ava ...

EPFL2009

A combined downscaling-disaggregation weather generator for stochastic generation of multisite hourly weather variables over complex terrain: Development and multi-scale validation for the Upper Rhone River basin

Abdelkader Mezghani

This paper presents a combined downscaling and disaggregation weather generator developed for multisite generation of hourly precipitation and temperature time series over complex terrain. Daily regional weather variables are first generated from Generaliz ...

2009

Generation of meteorological scenarios from NCEP reanalyses. Application for the generation of flood scenarios for the Rhone upstream to Lake Leman

Abdelkader Mezghani

Optimal water resources management requires hydrological scenarios for the climate situation under consideration. These scenarios may be produced from meteorological scenarios thanks to an appropriate hydrological model. The Laboratory "Hydrology and Land ...

2007

Development of probability distributions for regional climate change from uncertain global mean warming and an uncertain scaling relationship

Abdelkader Mezghani

A method is presented to produce probability distributions for regional climate change in surface temperature and precipitation. The method combines a probability distribution for global mean temperature increase with the probability distributions for the ...

2007

Modeling the influence of intermittent rain events on long-term fate and transport of organic air pollutants

The deposition of particles and substances in air is under strong influence of the precipitation patterns of the atmosphere. Most multimedia models, like type III Mackay models, treat rain as a continuous phenomenon. This may cause severe overestimation of ...

2005