Publications associées à Global Environmental Multiscale Model

Nowcasting of High-Intensity Rainfall for Urban Applications in the Netherlands

Radar rainfall nowcasting has mostly been applied to relatively large (often rural) domains (e.g., river basins), although rainfall nowcasting in small urban areas is expected to be more challenging. Here, we selected 80 events with high rainfall intensiti ...

Amer Meteorological Soc2024

An Elliptic Local Problem With Exponential Decay Of The Resonance Error For Numerical Homogenization

Assyr Abdulle, Doghonay Arjmand, Edoardo Paganoni

Numerical multiscale methods usually rely on some coupling between a macroscopic and a microscopic model. The macroscopic model is incomplete as effective quantities, such as the homogenized material coefficients or fluxes, are missing in the model. These ...

SIAM PUBLICATIONS2023

Improved extended-range prediction of persistent stratospheric perturbations using machine learning

Guillaume Romain Obozinski, Raphaël Gérard Théodore Michel Marie de Deloÿe et Fourcade de Fondeville

On average every 2 years, the stratospheric polar vortex exhibits extreme perturbations known as sudden stratospheric warmings (SSWs). The impact of these events is not limited to the stratosphere: but they can also influence the weather at the surface of ...

Copernicus Gesellschaft Mbh2023

The role of secondary ice production in mixed-phase clouds

Paraskevi Georgakaki

Clouds are omnipresent in the Earth's atmosphere. Their phase composition significantly modulates their interaction with solar and terrestrial radiation, as well as precipitation formation. Particularly for clouds containing both phases, known as mixed-pha ...

EPFL2023

Reinforcement Learning for the occupant-centric operation of building energy systems: Theoretical and experimental investigations

Amirreza Heidari

Occupant behavior, defined as the presence and energy-related actions of occupants, is today known as a key driver of building energy use. Closing the gap between what is provided by building energy systems and what is actually needed by occupants requires ...

EPFL2022

From coating flow patterns to porous body wake dynamics via multiscale models

Pier Giuseppe Ledda

Multiscale phenomena are involved in countless problems in fluid mechanics. Coating flows are known to exhibit a broad variety of patterns, such as wine tears in a glass and dripping of fresh paint applied on a wall. Coating flows are typically modeled und ...

EPFL2022

Augmenting the performance of impoverished sensor networks using machine learning and time reversal: Application to lightning nowcasting and location

Amirhossein Mostajabi

Lightning is formed in the atmosphere through the combination of intricate dynamic and microphysical processes. Mainly due to this complexity, attempts to solve the important problem of lightning prediction have generally failed to yield accurate results. ...

EPFL2021

Intercomparison of Large-Eddy Simulations of the Antarctic Boundary Layer for Very Stable Stratification

Etienne Gabriel Henri Vignon, Jing Huang

In polar regions, where the boundary layer is often stably stratified, atmospheric models produce large biases depending on the boundary-layer parametrizations and the parametrization of the exchange of energy at the surface. This model intercomparison foc ...

2020

LMDZ6A: The Atmospheric Component of the IPSL Climate Model With Improved and Better Tuned Physics

Etienne Gabriel Henri Vignon

This study presents the version of the LMDZ global atmospheric model used as the atmospheric component of the Institut Pierre Simon Laplace coupled model (IPSL-CM6A-LR) to contribute to the 6th phase of the international Coupled Model Intercomparison Proje ...

2020

Meteolakes: An operational online three-dimensional forecasting platform for lake hydrodynamics

Alfred Johny Wüest, Damien Bouffard, Theo Baracchini

Environmental management depends on high-quality monitoring and its meaningful interpretation. The combination of local weather dynamics, regional anthropogenic stresses and global environmental changes make the evaluation of monitoring information in dyna ...

PERGAMON-ELSEVIER SCIENCE LTD2020

Structural Screening and Design of Platinum Nanosamples for Oxygen Reduction

Kevin Rossi

Nanocatalyst-by-design promises to empower the next generation of electrodes for energy devices. However, current numerical methods consider individual and often geometrical closed-shell nanoparticles, neglecting how the coexistence of several and structur ...

AMER CHEMICAL SOC2020

Multiscale simulation of erosive wear in a prototype-scale Pelton runner

François Avellan, Ebrahim Jahanbakhsh, Sebastián Camilo Leguizamón Sarmiento, Siamak Alimirzazadeh

The technical capacity to predict the erosion process is instrumental for the optimization of the runner designs and operation strategies of hydroelectric plants. A multiscale model of erosion recently formulated by the authors and validated on a laborator ...

Pergamon-Elsevier Science Ltd2020

Penalization and Bayesian numerical methods for multiscale inverse problems

Andrea Di Blasio

In this thesis we consider inverse problems involving multiscale elliptic partial differential equations. The name multiscale indicates that these models are characterized by the presence of parameters which vary on different spatial scales (macroscopic, m ...

EPFL2019

Multiscale Modeling and Simulation of Erosive Wear in Pelton Turbines

Sebastián Camilo Leguizamón Sarmiento

Hydropower has been identified as a key technology to mitigate climate change due to its very low lifecycle greenhouse gas emission intensity and its capacity to integrate intermittent renewable energy sources such as wind and solar into the electrical gri ...

EPFL2019

Multi-scale modeling of the urban meteorology: Integration of a new canopy model in the WRF model

Dasaraden Mauree, Alain Clappier

Urban parametrizations have been recently developed and integrated in mesoscale meteorological models for a better reproduction of urban heat islands and to compute building energy consumption. The objective of the present study is to evaluate the value of ...

2018

Reviews and syntheses: the GESAMP atmospheric iron deposition model intercomparison study

Athanasios Nenes

This work reports on the current status of the global modeling of iron (Fe) deposition fluxes and atmospheric concentrations and the analyses of the differences between models, as well as between models and observations. A total of four global 3-D chemistr ...

2018

Numerical methods for hydraulic fracture propagation: a review of recent trends

Brice Tanguy Alphonse Lecampion, Xi Zhang

Development of numerical methods for hydraulic fracture simulation has accelerated in the past two decades. Recent advances in hydraulic fracture modeling and simulation are driven by increased industry and research activity in oil and gas, a drive toward ...

2018

A systematic approach for thermal stability predictions of chemicals and their risk assessment: Pattern recognition and compounds classification based on thermal decomposition curves

Thierry Meyer, Nadia Baati, Annik Nanchen, Laetitia Mage

In the context of process and product design, predictive models are increasingly employed. Decomposition properties of chemicals may be experimentally determined through calorimetric measurements, and a few molecular structure-based models- which correlate ...

Institution of Chemical Engineers2017

Multiscale methods for Stokes flow in heterogeneous media

Ondrej Budác

Fluid flow in porous media is a multiscale process where the effective dynamics, which is often the goal of a computation, depends strongly on the porous micro structure. Resolving the micro structure in the whole porous medium can, however, be prohibitive ...

EPFL2016

Concepts of Information Content and Likelihood in Parameter Calibration for Hydrological Simulation Models

There remains a great deal of uncertainty about uncertainty estimation in hydrological modeling. Given that hydrology is still a subject limited by the available measurement techniques, it does not appear that the issue of epistemic error in hydrological d ...

Asce-Amer Soc Civil Engineers2015