Laurent Orgogozo

• Ph.D
• Professor (Associate) at Université Toulouse III - Paul Sabatier

The Northern regions has warmed at an average rate 3.8 times higher than the global average since 1979. This Arctic Temperature Amplification causes the Arctic and sub-Arctic areas to be therefore subject to radical changes: snow cover disturbances, widespread greening & browning, diversification of plant & microbial communities and permafrost thaw...

Quantitative simulation of permafrost dynamics, both under current climatic conditions and future climate change scenarios, presents significant challenges. These include, but are not limited to, long computation times, the construction of accurate surface boundary conditions, and the estimation of transfer properties for soil, organic matter, and...

Carbon cycling in permafrost peatlands is strongly influenced by both hydrology and temperature and is closely linked to microtopography. In this study, we assessed soil temperature regimes in the sporadic permafrost zone of Western Siberia, one of the most climate-sensitive regions currently undergoing dramatic changes. Based on topographic mappin...

Permafrost thawing as a result of climate change has major consequences locally and globally, both for the biosphere and for human activities. The quantification of its extent and dynamics under different climate scenarios is needed to design local adaptation and mitigation measures and to better understand permafrost climate feedbacks. To this end...

Arctic environments are covered by millions of km² of permafrost-affected wetlands. The lowlands of Western Siberia are one of the largest of such areas. The low vegetation cover of these wetlands consists of Sphagnum moss, lichen, and peat. The spatial distribution of this vegetation layer is mainly driven by microtopography (Loiko et al., 2019)....

Permafrost dynamic involves non-linear processes and strong coupling between This work presents numerical simulations of permafrost dynamics under climate change in a forested watershed of the continuous permafrost zone of Central Siberia (Xavier et al., submitted). Projections until 2100 have been made for different scenarios of climate change wit...

This presentation aims at giving an overview of the porous media related activities of the HiPerBorea project, an ANR-funded project in its 5th and last year. The objective of this project is to enable quantitative and predictive modeling of the evolution under climate change cold regions hydrosystems. Arctic and sub-arctic areas, which are highly...

Permafrost thawing as a result of climate change has major consequences locally and globally for the biosphere as well as for human activities. The quantification of its extent and dynamics under different climate scenarios is needed to design local adaptation and mitigation measures and to better understand permafrost climate feedbacks. To this en...

A land cover map of two arctic catchments near the Abisko Scientific Research Station was obtained based on a classification from a Sentinel-2 satellite image and a ground survey performed in July 2022. The two contiguous catchments, Miellajokka and Stordalen, are covered by various ecotypes, from boreal forest to alpine tundra and peatland. Two cl...

A land cover map of two arctic catchments, nearby the Abisko Scientific Research Station, was obtained from a classification of a Sentinel-2 satellite image and a ground survey performed in July 2022. The two contiguous catchments, Miellajokka and Stordalen, are covered by various ecotypes, from boreal forest to alpine tundra and peatland. Two clas...

A land cover map of two arctic catchments, nearby the Abisko Scientific Research Station, was obtained from a classification of a Sentinel-2 satellite image and a ground survey performed in July 2022. The two contiguous catchments, Miellajokka and Stordalen, are covered by various ecotypes, from boreal forest to alpine tundra and peatland. The rand...

West Siberian wetlands act as important indicator and regulator of climate change on a global scale. The northern taiga of the sporadic permafrost is one of the most warming-sensitive regions undergoing dramatic changes. Carbon cycling in wetlands is strongly affected by hydrology, in addition to temperature and associated with microtopography. Tak...

In arctic regions, a complex patchwork of low vegetation layer consisting of Sphagnum moss, lichen, and peat covers the permafrost active layer on millions of km2, for instance in the lowlands of Western Siberia. Assessing the properties of this layer is crucial for modeling of soil thermal regimes, since this vegetation layer is the main interface...

Permafrost dynamic involves non-linear processes and strong coupling between thermal and hydrological transfers. A mechanistic approach to solve this stiff problem requires the use of High Performance Computing resources and adapted methodologies. For these reason the free, open-source solver permaFoam dedicated to permafrost simulation has been de...

Keywords: degree day model, data assimilation, transfer function model, soil surface temperature,climate change The Kulingdakan watershed is located in East Siberian region and has been studied and monitored for about two decades. It is located 5 km away from Tura city (64°17’ N, 100°13’E), where daily meteorological data (temperatures, snow heigh...

Thermal regimes of arctic soils are strongly correlated to the presence of perennially frozen soil layers (permafrost). These soils undergo a cyclic annual freeze-thaw phenomenon with the formation of an active layer during summer. A complex patchwork of low vegetation layer consisting of Sphagnum moss, lichen, and peat covers this active layer. Su...

A land cover map of two arctic catchments, nearby the Abisko Scientific Research Station, was obtained from a classification of a Sentinel-2 satellite image and a ground survey performed in July 2022. The two contiguous catchments, Miellajokka and Stordalen, are covered by various ecotypes, from boreal forest to alpine tundra and peatland. The Rand...

Permafrost covers a quarter of northern hemisphere lands and is highly sensitive to climate warming. The role of hydrological drains and thermal insulators of the moss and lichen layers, which are the most widespread vegetation covers on tundra and taïga ecosystems, is largely acknowledged to be of primary importance for permafrost dynamics but is...

Due to its insulating and draining role, assessing ground vegetation cover properties is important for high-resolution hydrological modeling of permafrost regions. In this study, morphological and effective hydraulic properties of Western Siberian Lowland ground vegetation samples (lichens, Sphagnum mosses, peat) are numerically studied based on to...

Permafrost, i.e., soil that is year-round frozen in depth, is covering a quarter of the continents of the northern hemisphere. It currently experiences fast changes due to climate change at global scale and technogenic perturbations at local scale, and the assessment and anticipation of these changes are of primary importance for many environmental...

Permafrost, i.e., soil that is year-round frozen in depth, is covering a quarter of the northern hemisphere lands, and most of it is located in Asia (Siberia, Himalaya). It currently experiences fast changes due to climate change at global scale and technogenic perturbations at local scale, and the assessment and anticipation of these changes are o...

Permafrost dynamics simulation - Code permaFoam - Open-source - High Performance Computing - Climate Change - ANR HiPerBorea - SLURM - Scalability Conference JCAD2022 : https://jcad2022.sciencesconf.org/resource/page/id/7 ANR HiPerBorea : https://hiperborea.omp.eu Code repository : https://develop.openfoam.com/Community/hydrology

In this paper, the platform CALLISTO (CALmip Launches an Interface for a Semantic Toolbox Online, https://callisto.calmip.univ-toulouse.fr/) is presented, aiming at open science construction around semantic description of scientific data, software and papers. This work aims tackling the needs for a fine-grained description of multidisciplinary scie...

Program Title: permaFoam CPC Library link to program files: https://doi .org /10 .17632 /swp88cvpwb .1 Developer’s repository link: https://develop .openfoam .com /Community /hydrology/ Licensing provisions: GPLv3 Programming language: C++ Nature of problem: This software solves the coupled equations that govern water flow and heat transfer in variab...

Boreal regions dynamics are strongly driven by perennially frozen soil (permafrost) physical properties. Sphagnum moss, lichen, and peat are widely present in these regions, forming a complex biological patchwork covering millions of km². In such regions, energy and mass transfers mainly occur via evapotranspiration, involving both vegetation hydra...

Permafrost, i.e., soil that is year-round frozen in depth, is covering a quarter of the continents of the northern hemisphere. It currently experiences fast changes due to climate change at global scale and technogenic perturbations at local scale, and the assessment and anticipation of these changes are of primary importance for many environmental...

To better understand freezing - thawing cycles operating in peat soils of permafrost landscapes, we experimentally modelled bi-directional freezing and thawing of peat collected from a discontinuous permafrost zone in western Siberia. We measured translocation of microorganisms and changes in porewater chemistry (pH, UV absorbance, dissolved organi...

The hydraulic properties of ground vegetation cover are important for high resolution hydrological modeling of permafrost regions, due to its insulating and draining role. In this study, the morphological and effective hydraulic properties of Western Siberian Lowland ground vegetation samples (lichens, Sphagnum mosses, peat) are numerically assesse...

Permafrost dynamics simulation - Code permaFoam - Open-source - High Performance Computing - Climate Change - ANR HiPerBorea Conference CMWR2022 : https://cmwrconference.org/ ANR HiPerBorea : https://hiperborea.omp.eu Code repository : https://develop.openfoam.com/Community/hydrology

The hydraulic properties of ground vegetation cover are important for high resolution hydrological modeling of permafrost regions, due to its insulating and draining role. In this study, the morphological and effective hydraulic properties of Western Siberian Lowland ground vegetation samples (lichens, Sphagnum mosses, peat) are numerically assesse...

The hydraulic properties of ground vegetation cover are important for high resolution hydrological modeling of permafrost regions, due to its insulating and draining role. In this study, the morphological and effective hydraulic properties of Western Siberian Lowland ground vegetation samples (lichens, Sphagnum mosses, peat) are numerically assesse...

Sphagnum moss, lichen and peat are widely present in arctic regions, covering millions of km² in permafrost-dominated regions. This multi-component low vegetation strata plays a key role in surfaces fluxes in these areas, as they are the most widespread interface between the atmosphere and the geosphere. Therefore, characterizing their transfer pro...

PermaFoam is the OpenFOAM solver for permafrost dynamics simulation. It has first been published in 2019 (Orgogozo et al., PPP 2019), and a new version is in revision for publication (Orgogozo et al., in revision). The new features of permaFoam are presented, with new parallele performances assessments and examples of applications.

Le pergélisol couvre de vastes surfaces des régions polaires, et a des conséquences majeures sur les hydrosystèmes, les écosystèmes et les activités humaines. Le réchauffement climatique, si intense aux hautes latitudes, conduit à une réduction de son extension et à un épaississement de sa couche active. Anticiper ces impacts est donc un enjeu cruc...

To better understand freezing - thawing cycles operating in peat soils of permafrost landscapes, we experimentally modelled bi-directional freezing and thawing of the three sections of 90-cm long peat core collected from a discontinuous permafrost zone in western Siberia. We measured translocation of microorganisms and changes in porewater chemistr...

RichardsFoam3 is an updated version of the OpenFOAM solver RichardsFoam, previously presented in ”An open source massively parallel solver for Richards equation: Mechanistic modelling of water fluxes at the watershed scale” by L. Orgogozo et al (2014, Computer Physics Communications 185 : 3358-3371. DOI: 10.1016/j.cpc.2014.08.004), and in the new v...

Boreal peatlands are one of the most important stocks of active carbon on continental surfaces (Helbig et al., 2020). The Western Siberia Lowlands are the largest boreal peatlands on earth, with about 2 milllions of km2, and almost half of this vast area is constituted of frozen peats highly sensitive to climate warming (Pokrovsky et al., 2018). Be...

Western Siberia lowlands vegetation cover consists of a complex patchwork of bryophytes (mosses s.l.), lichens (symbiotic association of heterotrophic Fungus and autotrophic Algae) and underlying peat (Volkova et al., 2018). This vegetation cover is the main interface between permafrost driven soil dynamics and the atmosphere. The energetic transfe...

Permafrost is year round frozen soil, which covers 25% of the land of the northern hemisphere. The presence of permafrost affects tremendously both the natural processes (e.g.: water cycle) and the human activities (e.g.: building) in the affected areas. Its dynamics is governed by strongly coupled heat and mass (mainly water) transport, with coupl...

PermaFoam, the OpenFOAM® solver for permafrost modeling, has recently been used to characterize the thermo-hydrological dynamics of the Kulingdakan catchment, an experimental watershed in Central Siberia that is monitored since more than a decade (Orgogozo et al., 2019). Following this study of water and energy fluxes in a permafrost-dominated, for...

Permafrost is a peculiar soil type of cold areas that is year-round frozen in-depth. Permafrost dynamics (e.g.: seasonal freeze/thaw cycles close to the surface, extension/retreat under climate changes) as strong impacts on both natural processes and engineering activities in cold regions (e.g.: Walvoord and Kurylyk, 2016). The involved physics are...

Le permafrost (pergélisol) est un type de sol spécifique des régions froides, qui est gelé toute l'année en profondeur. La dynamique du permafrost (e.g.: cycle saisonniers de gel/dégel près de la surface, extension/retrait latéral sous changement climatique) a des impacts importants aussi bien sur les processus naturels que sur les activités humain...

(english version below) Эвапотранспирация растений – важнейший параметр, контролирующий динамику гидрологического и теплового режима почв на водосборных бассейнах зоны бореальных лесов. В частности в криолитозоне, эвапотранспирационные потоки оказывают существенное воздействие на мощность сезонно-талого слоя, главным образом из-за их влияния на со...

(english version below) Эвапотранспирация растений – важнейший параметр, контролирующий динамику гидрологического и теплового режима почв на водосборных бассейнах зоны бореальных лесов. В частности в криолитозоне, эвапотранспирационные потоки оказывают существенное воздействие на мощность сезонно-талого слоя, главным образом из-за их влияния на с...

The biogeochemical transfers in the catchment of the Kulingdakan stream, which is a small tributary of the Kochechum river in the Yenisei basin, have been studied for more than a decade. Measurements of the chemical composition of the waters in the stream and in the other compartments of the watershed, such as mineral soil or litter horizons for in...

This file contains a presentation that gives some information about the validation of the solver permaFoam (Orgogozo et al., 2019)* in the framework of the Interfrost international benchmark (Grenier et al., 2018)**. * L. Orgogozo, A.S. Prokushkin, O.S. Pokrovsky, C. Grenier, M. Quintard, J. Viers, D. Labat, S. Audry, 2019. Water and energy transf...

this file contains the three appendixes listed hereafter: Appendix S1: Full set of governing equations and parameterizations considered for the description of the water and thermal transfer in variably saturated porous media with freeze/thaw of the pore water. Appendix S2: Used data set for the thermo-hydrological properties of the soils. Appendi...

This is the preprint of the paper "Water and energy transfer modeling in a permafrost‐ dominated, forested catchment of Central Siberia: The key role of rooting depth" by L. Orgogozo , A.S. Prokushkin, O.S. Pokrovsky, C. Grenier, M. Quintard, J. Viers and S. Audry, published in Permafrost and Periglacial Processes in 2019.

PermaFoam is an OpenFOAM (openfoam.com) solver for cryohydrogeology. It solves coupled water and heat transfers in variably saturated porous media, considering freeze/thaw of the pore water. The main field of application is the modeling of permafrost thermo-hydrological dynamics. A first example of application may be found in the paper "Water and e...

To quantify the impact of evapotranspiration phenomena on active layer dynamics in a permafrost‐dominated forested watershed in Central Siberia, we performed a numerical cryohydrological study of water and energy transfer using a new open source cryohydrogeology simulator, with two innovative features: spatially distributed, mechanistic handling of...

Evapotranspiration has a major control on continental surfaces dynamics in forested boreal environments. For example, it has strong impacts on active layer thickness, mainly because of its effect on water content within the upper layers of the soil column. These are complex processes, depending not only on climate forcings (atmospheric water demand...

In this paper we present a massively parallel open source solver for Richards equation, named the RichardsFOAM solver. This solver has been developed in the framework of the open source generalist computational fluid dynamics tool box OpenFOAM (R) and is capable to deal with large scale problems in both space and time. The source code for RichardsF...

This package contains an updated version of RichardsFoam2 that is compatible with OpenFOAM-v1712. In RichardsFoam2 (Orgogozo, 2015), new features were implemented compared to RichardsFoam (Orgogozo et al., 2014). This software solves the non-linear three-dimensional transient Richards equation, which is a very popular model for water transfer in va...

Oral presentation given at the 5th EUropean Conference On Permafrost (EUCOP 5) held in Chamonix, France (25th-29th june 2018).

In high-elevation, boreal and arctic regions, hydrological processes and associated water bodies can be strongly influenced by the distribution of permafrost. Recent field and modeling studies indicate that a fully-coupled multidimensional thermo-hydraulic approach is required to accurately model the evolution of these permafrost-impacted landscape...

Copper (Cu) based pesticides are widely used in viticulture and are permitted in organic viticulture. Due to its extensive long term use, Cu accumulates in vineyard soils and ecotoxicological implications are growing. In this study, the cycling of Cu based pesticides was investigated in vineyard environments using copper mass balance, electron para...

This work presents a numerical solver for the multiphysics problem of hydric and thermal transfers in variably water saturated porous media with freeze/thaw of the poral water. The application that we aim to deal with is the study of the dynamics of permafrosts, which are constituted of soils and geological bodies frozen in depth all year round, wi...

Copper (Cu) based fungicides have been applied in European vineyards from the appearance of mildew in the late 19th century to the present day, particularly in organic viticulture. Even though its application is foliar, most of the Cu reaches the soil after being washed off or following leaf fall. As Cu accumulates in soils, the use of Cu based fun...

This work presents a numerical study of water and energy transfers within a permafrost dominated experimental watershed of Central Siberia, the Kulingdakan catchment (e.g.: Viers et al., 2015). This watershed has been studied for years in order to characterize and quantify the elementary transfers from the slopes to the stream along the seasonal cy...

PermaFoam est un solveur OpenFOAM® dédié au problème de transferts couplés hydriques et thermiques dans un sol avec gel/dégel de la phase aqueuse. Il a été développé pour l'étude de la dynamique thermo-hydrique des pergélisols dans un contexte de changement climatique, l’objectif étant de contribuer à la quantification des flux élémentaires des sur...

RichardsFoam2 is an updated version of the OpenFOAM solver RichardsFoam, presented in Orgogozo et al., Comput. Phys. Commun. 2014. The new features are the following: (i) the direct handling of fully heterogeneous porous media, with all the van Genuchten parameters defined as spatially varying scalar fields. (ii) the computation of the density of...

RichardsFoam2 is an updated version of the OpenFOAM® solver RichardsFoam, presented in Orgogozo et al., Comput. Phys. Commun. 2014. The new features are the following: (i) The direct handling of fully heterogeneous porous media, with all the van Genuchten parameters defined as spatially varying scalar fields. (ii) The computation of the density of...

Keywords : Transfers in soils, richards equation, parallel computation. The infiltration of rain waters through soils are determinant for numerous engineering applications (water ressources, environment, geotechnics, …) as well as in various natural phenomena, such as for instance weathering of continental surfaces (e.g.: Goddéris et al., 2012), w...

Understanding the influence of soil composition in wine taste is of great economic and environmental interest in France and around the world. Nevertheless the impact of soil composition on wine taste is still controversially discussed. Since inorganic soil components do not have a proper taste and do not enter the plant anyway, their influence need...

The impacts of climate change in boreal regions has received considerable attention recently due to the warming trends that have been experienced in recent decades and are expected to intensify in the future. Large portions of these regions, corresponding to permafrost areas, are covered by water bodies (lakes, rivers) that interact with the surrou...

In this paper we present a massively parallel open source solver for Richards equation, named the RichardsFOAM solver. This solver has been developed in the framework of the open source generalist computational fluid dynamics tool box OpenFOAM® and is capable to deal with large scale problems in both space and time. The source code for RichardsFOAM...

In subsurface systems, biofilm may degrade organic or organometallic pollutants contributing to natural attenuation and soil bioremediation techniques. This increase of microbial activity leads to change the hydrodynamic properties of aquifers. The purpose of this work was to investigate the influence of biofilm‐induced heterogeneities on solute tr...

RichardsFOAM: résolution de l’équation de Richards en calcul à haute performance Laurent Orgogozo∗1, N. Renon2, C. Soulaine3, F. Hénon3, S.K. Tomer4, D. Labat1, O.S. Pokrovsky1,5, M. Sekhar6, R. Ababou3, M. Quintard3,7 1 GET (Géosciences Environnement Toulouse), Observatoire Midi-Pyrénées, Université Paul Sabatier, Université de Toulouse; 14 avenue...

In this paper we present a massively parallel open source solver for Richards equation, which will be design as RichardsFOAM solver. This solver has been developed in the framework of the open source computational fluid dynamics tool box OpenFOAM®. It exhibits good parallel performances (up to ~90% of parallel efficiency with 1024 processors both i...

This chapter deals with the thermo-hydrological determinants of weathering fluxes in boreal watersheds, and with the insights on this matter that may be expected from a mechanistic modeling approach. Focus will be placed on the weathering fluxes in the permafrost dominated watersheds of the basaltic region of the Putorana Plateau in Central Siberia...

An OpenFOAM massively parallel solver for Richards Equation : towards mechanistical modelling of transfers at the watershed scale L. Orgogozoa, D. Labata, N. Renonb, S.K. Tomerc, C. Soulained, F. Hénond, R. Ababoud, M. Quintardd,e aGET (Géosciences Environnement Toulouse), Observatoire Midi-Pyrénées, Université Paul Sabatier, University of Toulous...

Application of high performance computation methods to the study of transfers in porous media hosting biofilms L. Orgogozoa, R. Martina, R. Guibertb, F. Golfierc, C. Noiriela, G. Debenestb, M. Quintardb,d aGET (Géosciences Environnement Toulouse), Observatoire Midi-Pyrénées, Université Paul Sabatier, University of Toulouse, 14 avenue Edouard Belin...

In subsurface systems, biofilm may degrade organic or organo-metallic pollutants contributing to natural attenuation and soil bioremediation techniques. Biofilm accumulation, however, decreases free pore space thereby decreasing media porosity and permeability while increasing hydrodynamic dispersion (e.g., [1]). This mechanism commonly referred to...

In subsurface systems, biofilm may degrade organic or organo-metallic pollutants contributing to natural attenuation and soil bioremediation techniques. Mathematical modeling plays a crucial role in understanding biofilm dynamics and predicting efficiency of these decontamination methods. First, we investigate the capability of single- and double-p...

In this paper we show the potentiality of application of transport models by upscaling to the study of the biofilms dynamics in potable water system. The development of bacterial population under the form of biofilms in potable water system is the source of many serious issues, such as the decreasing of the bacteriologic quality of the water, of it...

In this work, we derive two different Darcy-scale models for the transport of biodegradable solutes in porous media containing a microbial biomass that developed under the form of a biofilm. Biofilms are composed of bacterial populations and extra cellular polymeric substances, and grow attached to a solid–fluid interface, e.g. the pore walls of a...

Transport of biologically reactive dissolved solutes in a porous medium including a biofilm phase is a complex process involving a wide variety of scales (from the bacteria scale to the aquifer heterogeneity scale) and processes (hydrodynamic, physicochemical and biochemical). The objectives of this work are 1) to derive a two-equation macroscopic...

Modeling transport in porous media of organic chemical solute in presence of a bacterial population growing as biofilms is an important area of research for environmental applications, for example for remediation of groundwater contaminated by organic pollutants (biosparging, bio-barriers ...). Biofilms, which are composed of bacteria and extracell...

Transport of biologically reactive dissolved solutes in a saturated porous medium including a biofilm-phase occurs in various technological applications such as in biochemical or environmental engineering. It is a complex process involving a wide variety of scales (from the bacteria-scale to the aquifer-heterogeneities-scale in the case of groundwa...

In this work, we upscale a pore-scale description of mass transport in a porous medium containing biofilm to develop the relevant Darcy-scale equations. We begin with the pore-scale descriptions of mass transport, interphase mass transfer, and biologically-mediated reactions; these processes are then upscaled using the method of volume averaging to...

Transport of biologically reactive dissolved solutes in a porous medium including a biofilm phase is a complex process involving a wide variety of scales (from the bacteria scale to the aquifer heterogeneity scale) and processes (hydrodynamic, physicochemical and biochemical). The objectives of this work are 1) to present one-equation macroscopic m...

Modeling transport in porous media of organic chemical species in the presence of a bacterial population growing in the form of biofilms is an important area of research for environmental applications, including groundwater remediation. Biofilms, which are composed of bacteria and extracellular organic substances, grow on the grains of a porous med...

EUROMECH 499, Nonlinear Mechanics of Multiphase Flow in Porous Media, Nancy, 9-12 June.

In a porous medium, biofilms, which are composed of bacteria and extracellular organic substances, grow on the pore walls. Bacterial metabolism converts organic solutes into biomass. The governing system of equations of bio-reactive transport at the Darcy scale in a porous media including a biofilm phase has been derived from the data available at...

Dans un milieu poreux, les biofilms, composés de bactéries entourées de substances organiques extracellulaires, se développent généralement sur les parois des pores. Le métabolisme bactérien convertit les solutés organiques en biomasse. Le système d'équations régissant à l'échelle de Darcy le transport bio-actif d'un soluté organique dans un milieu...