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MODEST Challenge

Environment and Security Modelling

The impact of human activities on the environment and security is an important social issue. CERFACS teams have developed in recent years recognized expertise in the field of natural and industrial risks through their contributions to the projects related to the monitoring of the environment and natural resources, natural and industrial sites at risk. This work was undertaken in synergy with CERFACS partners.  The main  activities are:

  • the impact of transportation modes on climate and atmospheric composition;
  • the air quality at regional and global scales;
  • the simulation of forest fire;
  • the simulation and flood forecasting;
  • the study of industrial sites and explosion risks.

The diversity of the studied risks  results in a diversity of objectives (monitoring, alerting, re-analysis, scenario …), spatio-temporal scales (from a few hundred meters to several hundred kilometers), simulation tools (CFD, hydrodynamics, front propagation, aerodynamics) and algorithms to estimate the risk (direct numerical simulation, optimization and assimilation methods, methods for quantifying uncertainties, multi-dimensional code coupling and / or multi-physics ).

The MODEST challenge integrates a strong digital component and mobilizes all CERFACS teams.  The MODEST Challenge is related to the transverse lines of research “Data Assimilation and Optimization“, “Uncertainties” and the application axis “Environment“, “Combustion“, “Aerodynamics” and “Climate“.

Objectives

The MODEST Challenge aims to develop:

  • innovative methodological tools (modeling at different scales, coupling between physical and chemical processes, code coupling and data assimilation) applied to concrete problems encountered by the CERFACS associate members;
  • applications to the decision aspiring for operational, particularly for air quality, the spread of forest fires and hydrology / hydraulics.

Projects

Started in late 2014, the MODEST Challenge enabled the initiation of works in the fields of air quality and hydrology, notably through  European projects (MACC, EoCoE) and national projects (LEFE, SCHAPI, TOSCA) .

Flood forecasting and flood

hydro

Multi-dimensionnal 1D/2D hydraulics coupling en hydraulique, with data      assimilation on the Adour.

 

 

Modeling and flood forecasting answer a major challenge: managing water resources and natural hazards. At CERFACS, data assimilation methods are implemented to improve the predictive capacity of hydraulic numerical models limited by uncertainties on knowledge of watersheds, meteorological, hydrological and geographical. The DAMP platform enables real-time forecasting of floods from a river hydraulics code. Works multi-dimensional coupling for 1D / 2D hydraulics allow to model complex flows by limiting the cost calculations in order  to meet the operational and industrial constraints.

 

 

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Wildland fire spread and emissions

front_fire

Corrections of simulated fire front (blue) by the assimilation of aribone observations (gray) to obtain an analyzed front position.

 

The improvement of real-time forecasting systems for the spread of forest fires and associated emissions paves the way for direct applications on emergency fire risk management and quality management of the regional air and climate scale. The FIREFLY platform, co-developed by CERFACS and the University of Maryland (Dept. of Fire Protection Engineering, USA) is based on a comprehensive set-data assimilation algorithm type Kalman filter, implemented on a model semi-empirical spread of fire front. This system combines parameter estimation (surface wind, humidity and plant fuel properties) and state estimation (the position of the fire front) to improve the prediction of the position of the fire front in real time.

 

 

 

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Aviation and environment

Evaluation de l'impact des émissions anthropiques

 

CERFACS assesses the impact of anthropogenic emissions that affect atmospheric chemistry and radiation balance by complex and indirect mechanisms (streaks of water vapor condensation on aerosols, soot particles responsible for the formation of cirrus clouds, emissions ‘nitrogen oxides …) that disrupt the natural cycles, including that of ozonne, which, combined with other chemical cycles, have an impact on the anthropogenic greenhouse effect

 

 

NEWS

NextSim General Assembly and TC meeting

CERFACS |  16 September 2021

The General Assembly and TC Meeting took place on 15-16 September 2021. CERFACS is involved in the NextSim project (). The primary objective is to increase the capabilities of Computational Fluid Dynamics tools on extreme-scale parallel computing platforms for aeronautical design. This project has received funding from the European High-Performance Computing Joint Undertaking (JU) under grant agreement N° 956104. The JU receives support from the European Union’s Horizon 2020 research and innovation programme and Spain, France, Germany. This project has received funding from the Agence Nationale de la Recherche (ANR) under grant agreement N° ANR-20-EHPC-0002-02. For more information, please visit Read more


Sophie Valcke from Cerfacs co-authored a new book on atmosphere-ocean modelling

CERFACS |  18 August 2021

new book "Atmosphere-Ocean Modelling - Couling and Couplers” by Prof. Carlos R Mechoso, Prof. Soon-Il An and Dr Sophie Valcke has just been published by World Scientific. The present book fills a void in the current literature by presenting a basic and yet rigorous treatment of how the models of the atmosphere and the ocean are put together into a coupled system. Details are available at  Abstract: Coupled atmosphere-ocean models are at the core of numerical climate models. There is an extraordinarily broad class of coupled atmosphere-ocean models ranging from sets of equations that can be solved analytically to highly detailed representations of Nature requiring the most advanced computers for execution. The models are applied to subjects including the conceptual understanding of Earth’s climate, predictions that support human activities in a variable climate, and projections aimed to prepare society for climate change. The present book fills a void in the current literature by presenting a basic and yet rigorous treatment of how the models of the atmosphere and the ocean are put together into a coupled system. The text of the book is divided into chapters organized according to complexity of the components that are coupled. Two full chapters are dedicated to current efforts on the development of generalist couplers and coupling methodologies all over the worldRead more

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