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Interfaces and Troposphere
Mineral dust modelled with WRF-CHIMERE online model
Mineral dust modelled with WRF-CHIMERE online model
Research topics
The team is coordinated by Laurent Menut. Members of the InTro group study the physical and chemical properties of the troposphere and its interfaces. Our scientific interests include:

Regional climate and water cycle

Study of the Water cycle in InTRo is focused on the Mediterranean region, in the framework of international initiatives HyMEx and MedCORDEX, but also in the basins of the major Chinese rivers. In the Mediterranean area, studies of the hydrological cycle and hydrological extremes (extreme precipitation, dry spells) has relied in part on the RegIPSL regional coupled modelisation platform, under development in the InTRo team in collaboration with other IPSL teams. Scientific focuses in the team include interactions between aerosols and precipitation, studying the runoff of major hydrologic basin including major Chinese rivers for which anthropogenic use of the water is critical. Study of the regional water cycle is one of the strong reasons why the InTRo team is currently strongly involved in the development of the RegIPSL regional coupled model.

Non permanent:
Julie André (Doc)
Laure Baratgin (Doc)
Julie Collignan (Post-doc)
Douglas Keller (Post-Doc)
Juan Pablo Sierra (Post-Doc)

C/EC permanent:
Philippe Drobinski (DR CNRS)
Thomas Dubos (Pr Polytechnique)
Patryk Kiepas (IR Polytechnique)
Sylvain Mailler (IPEF ENPC)
Romain Pennel (IR Polytechnique, TC)
Jan Polcher (DR CNRS, SC)

Impact of climate on renewable energies

The InTRo team also contributes to interdisciplinary work at the interface between atmospheric and climate sciences and energy economics and engineering. A first line of research of the team in this field deals with the potential, predictability and value of the Variable Renewable Energy (VRE, mainly wind and solar) ressource. It involves understanding the variability and trends of the VRE potential in association to dynamical and thermodynamical processes at scales ranging from the boundary layer to the planet; reexamining the statistical modelling of instant VRE value; improving sub-seasonal to seasonal prevision of VRE by combining dynamical and statistical models and estimating the economic value of such previsions. A second line of research is concerned with the long-term increase in the sensitivity of the energy system to meteorological conditions associated with increasing VRE penetration and with rising demand thermosensitivity due to electrification. These activities are underpinned by interdisciplinary collaborations within the Energy4Climate center.

Non permanent:
Laure Baratgin (Doc)
Samouro Dansokho (Doc)
Joan Delort (Doc)
Camille Le Coz (Post-Doc)
Lia Rapella (Doc)
Qiqi Tao (Doc)
Ganglin Tian (Doc)

C/EC permanent:
Philippe Drobinski (DR CNRS)
Jan Polcher (DR CNRS)
Alexis Tantet (MdC Polytechnique, SC)

Chemistry-transport from urban to hemispheric scales

The study of the atmospheric composition is an important research topic in the InTRo team. In particular, the team coordinates the development of the CHIMERE chemistry-transport model, which is largely used in France and abroad for research and operational air quality simulations, including the French and European forecast platforms Prev'Air and CAMS. The main topics of research in this field include wildfire emissions with the development of the emifiresCAMS code, mineral dust emissions from arid areas and their subsequent transport, the transport of volcanic plumes as well as the development of downscaling techniques to address urban scale atmospheric pollution and population exposure with the EXPLUME model.

Non permanent:
Léo Adenis (Post-Doc)
Sanhita Ghosh (Post-Doc)
Alexis Squarcioni (Doc)

C/EC permanent:
Arineh Cholakian (IE CNRS, TC)
Sylvain Mailler (IPEF ENPC)
Laurent Menut (DR CNRS, SC)
Romain Pennel (IR Polytechnique)
Myrto Valari (CNAP PA)

TC: Technical coordinator
TS: Scientific coordinator
Recents results
Regional climate and water cycle: Shallow and deep convection over the southern Amazon during the dry-to-wet transition season: An analysis from twin deforested/forested experiments
Juan Pablo Sierra, Jan Polcher, Sophie Bastin, Romain Pennel, Lluis Fita, Jhan Carlo Espinoza, Sly Wongchuig
  • Southern Amazon is the basin's most vulnerable region to anthropogenic activity (high deforestation/warming).
  • Reduced rainfall, more dry days during the dry-to-wet transition, and longer dry season/shorter wet season in last decades.
How can forest loss impact the development of convection and the onset of the rainy season?
Main results:
  • Shallow convection occurs over crop-to-forest transition zones while deep convection is favored over forested areas.
  • Deep convection is favored by specific regional flow.
  • Deforestation reduces shallow convection triggered by the roughness length effect.
Impact of climate on renewable energies: Can we study climate and socioeconomic changes separately?

Joan Delort Ylla, Alexis Tantet, Philippe Drobinski
  • We create socioeconomic scenarios of heating demand electrification and AC adoption (MOD),
  • We use CMIP5 climate change scenarios for wind and solar resource as well as temperature (+1.75oC, +2.35oC, +2.80oC, +3.28oC, +4.04oC),
  • We compute indicators representing the capacity of adaptation of the power system (NAC, PAC, CoU),
  • We show that these indicators need to be computed by accounting for the compound effect of climate and socioeconomic change: studying both phenomena separately is misleading.
Could we improve the forecasting skill of renewable energies?

Ganglin Tian, Camille Le Coz, Alexis Tantet
  • Methodology The study presents a non-linear statistical ensemble forecasting method to predict wind speeds from Z500 forecasts.It evaluates this non-linear model against ECMWF dynamic forecasts and a linear model, focusing on their skills to predict weekly-mean surface wind speeds from week 3 to week 6.
  • Results
    • Better probabilistic skills than ECMWF.
    • Improvements to wind speed ensembles are seen across Europe.
    • Perturbations improve ensemble reliability
    • Improvement in MSE and CRPS with nonlinear methods is regional, such as in the North Sea.
Atmospheric pollution: Hemispheric transport of radioactive gas and aerosols plumes

Leo Adenis, Sylvain Mailler, Laurent Menut
Comparison between Eulerian and Lagrangian transport modelling
  • Two models: FLEXPART and CHIMERE
  • Ruthenium 106 plume in the Northern Hemisphere
  • Update of transport numerical schemes
  • Better results with CHIMERE, compared to surface stations measurements
Adding radioactive evolution:
  • Measurements: Station in Canada (C17) from OTICE network (Organisation du Traite d'Interdiction Complete des Essais nucleaires)
  • Models: WRF-CHIMERE, simulation Fukushima 2011.
    • Non reative gaseous tracers (red)
    • adding nuclear dependancy (orange)
    • adding semi-volatility and radioactivity (green)
    • (Project LRC Yves Rocard, CEA-DAM et ENS/LMD)
Atmospheric pollution: Explicit formulae for the calculation of the settling speed of non-spherical aerosols

Mailler S., Cholakian A., Pennel R., Menut L.
We have developed new, explicit formulae that describe the settling speed of non-spherical particles in the atmosphere, including the necessary corrections for large particles. Corrections reach:
  • -10% for lambda=2
  • -20% for lambda=4
Future prospects:
  • Take into account the probability distribution of particle orientation
  • study differential advection/sedimentation in CHIMERE
  • Take into account the optical effects of non-sphericity
Atmospheric pollution: CHIMERE, towards an unstructured mesh

Pennel R., Mailler S., Dubos T., Cholakian A., Menut L. (projet Escalair)
  • IPSL dynamical core (global and icosahedral grid)
  • Development of the regional version with unstructured mesh
  • Parallel efficiency : scale up to 1e4 cores / GPU oriented
Combine CHIMERE and DYNAMICO to:
  • Improve performances
  • Locally refined mesh in areas of interest
  • Multi-scale simulations without need for nesting
  • Use of DYNAMICO low level coding structure
  • Time-loop
  • Management of parallel mesh (MPI, allocations)
  • Chemistry solved in CHIMERE and transported in DYNAMICO
Models developments


Ocean model
web site
The NEMO-Med model


Urban to hemispheric chemistry-transport model
web site
The CHIMERE model


Dynamical model
The DYNAMICO model
Post-doc CEA-ENS
    ANDRÉ Julie
PhD Student, ENS
    BARATGIN Laure
PhD Student, Polytechnique
Site:X, J
Engineer, CNRS
Site:X 51 54
Post-doc, Polytechnique
    DANSOKHO Samouro
PhD Student, Polytechnique
Site:X 51 57
PhD Student, Polytechnique
    DROBINSKI Philippe
Research scientist, DR CNRS
Site:X 51 42
    DUBOS Thomas
Assistant Prof. Polytechnique
Site:X 51 43
GHOSH Sanhita
Post-doc ADEME
Site: X
    KELLER Douglas
Post-doc, Polytechnique
Site:X 51 70
    KIEPAS Patryk
Research Engineer Polytechnique
Site:X 51 34
LE COZ Camille
Post-doc E4C
    MAILLER Sylvain
Research Scientist, ENPC
Site:X 51 91
    MENUT Laurent
Research scientist, DR CNRS
Site:X 51 75
Research Engineer Polytechnique
Site:X 52 33
    PEREZ SIERRA Juan-Pablo
Post-doc, Polytechnique
Research scientist, DR CNRS
Site:X 51 46
PhD Student, Polytechnique
Site:X, LSCE
PhD Student
    TANTET Alexis
Assistant Prof. Polytechnique
Site:X 51 42
TAO Qiqi
PhD Student, Polytechnique
    TIAN Ganglin
Post-doc, Polytechnique
    VALARI Myrto
Assistant Physicist, Sorbonne Univ.
Site:J 61 00

  1. March 2024
  2. February 2024
  3. January 2024