Philippe PEYLIN

Research interests

I’m a global an environmental scientist studying the interactions between terrestrial ecosystem dynamic and environmental changes (climate, land use,..) more specifically the dynamic impacts on carbon, water and energy cycles at scales ranging from the ecosystem to the globe. I primarily develop and subsequently use process-based land surface models in combination with site-scale and satellite observations to unravel  the physical and biogeochemical responses to anthropogenic perturbations.  A wide array of data assimilation techniques enables me to make the best use of both models and data.  My research is aimed towards understanding : (i)  the fate of the terrestrial carbon sink and its main drivers , (ii) the coupling of, and the interaction between, the water and carbon cycles in the soil-plant-atmosphere continuum, and (iii) the sensitivity of future climate model projections to ultimately enhance our ability to mitigate and/or adapt to global change including all  feedbacks between  terrestrial ecosystems and the climate. Over the years, I have focussed on a multitude of topics which required me to invest time and resources in developing numerical methods and models across spatial and temporal scales. My most satisfying main contributions, often going beyond the –at that time- state of the art  are  :

•  A numerical model for atmospheric inversion of CO₂ concentrations and others tracers such as the isotopomeres of CO₂, COS, CH₄, to deduce surface CO₂ sources and sinks. This model contributed to a  comprehensive synthesis/review of all state of the art atmospheric inversions (Peylin et al. 2014);
• A skilful data assimilation system (DA) that can handle multi data streams and multi-scale in a single run. This DA was fully integrated in the global land surface model ORCHIDEE. A dedicated web-site summarizes the main results (ORCHIDEE data assimilation system), including the first study combining satellite vegetation indexes, eddy-covariance measurements of carbon and water fluxes,  and atmospheric CO₂ concentrations into a single DA framework (Peylin et al. 2016);
• The co-development of specific processes and components of the land surface model ORCHIDEE, for example,a novel numerical solution for a multi-layer energy budget for vegetation canopies including its implicit coupling to the atmosphere (Ryder et al. 2016);
• The co-development of a numerical model for the transfer of isotopes in the soil-plant-atmosphere continuum (¹⁸0 in water and CO₂; ¹³C).

Prospective students

Over the years I have enjoyed supervising tens of Master, PhD and postdocs of which several got competitive positions in academia, governmental bodies and industry.  If you have a Master or PhD degree in mathematics, physics, computer science, meteorology, plant physiology, or related topics, and find my research exciting, please, send me your cv and a motivation letter. If I share your vision, I may contact you to discuss your next research position at the LSCE. I believe the LSCE provides an intellectually stimulating environment for high-level research and is a lively science hub bringing together over 200 climate modelers and experimentalists from over 30 nationalities.

Institutional responsibilities

I am currently the Team leader of the “Modeling the continental surfaces and interfaces” team (around 30 researchers) and the Project Manager of a project dedicated to the development of the global land surface model, ORCHIDEE (the land surface component on the French IPSL Earth System Model), that gathers more than 100 Research scientists, post-docs and PhDs at several French institutes and universtities outside of France (Europe and China).

Current Grants / Projects

Project Title	Funding source	Amount (€)	Period	My role
VERIFY	H2020	10 M€ total (2 M€ for LSCE)	2017-2021	Coordinator ; Observation-based system for monitoring and verification of greenhouse gases
MULTIPLY	H2020	100 k€ (for me)	2016-2019	WP contributor: Assessment of the potential of high resolution satellite data to constrain land surface models
CRESCENDO	H2020	250 k€ (my activity)	2015-2019	Responsible for the french contribution to land developments
CAMS41	Copernicus	400 k€ (my activity)	2016-2019	Responsible of the project; contribution to the GhG modeling system of the ECMWF Integrated Forcasting System.
CCI-HRLandCover	ESA	120 k€ (my activity)	2012-2017	Co-Responsible for the French contribution on the use of the ESA-CCI Land cover products
BIOMASS	CNES french space agency	60 k€ / year (my activity)	2015-2019	Evaluation of the potential of forest biomass data from the ESA BIOMASS mission

Curriculum Vitae

Current & Past Positions

2010 – Present : Permanent research scientist at Laboratoire des Sciences du Climat et de l’Environnement (LSCE), in Gif-sur-Yvette, France for the National Center for Scientific Research (CNRS).

2001-2012: Permanent research scientist at Laboratoire de Biogéochimie et écologie des milieux continentaux (BIOEMCO), in Grignon, France for the National Center for Scientific Research (Le Centre national de la recherche scientifique; CNRS).

1999-2000: Post-doc at Laboratoire des Sciences du Climat et de l’Environnement (LSCE), in France.

1993-1995: Civil service at the National Center for Atmospheric Research (NCAR, Boulder, USA) where I studied the effect of the land surface processes on the atmosphere with a general circulation model.

Education

1995 – 1998: PhD studies at the Laboratoire des Sciences du Climat et de l’Environnement (LSCE). Translated title: “Using 18O concentration of atmospheric CO₂ to quantify the role of vegetation in the uptake of CO₂ emissions from industrial activities. Supervisor: Philippe Ciais. PhD obtained at the Université Pierre et Marie Curie, Paris VI, France.

1995 – 1998: PhD studies at the Laboratoire des Sciences du Climat et de l’Environnement (LSCE). Translated title: “Using 18O concentration of atmospheric CO₂ to quantify the role of vegetation in the uptake of CO₂ emissions from industrial activities. Supervisor: Philippe Ciais. PhD obtained at the Université Pierre et Marie Curie, Paris VI, France.

1991 – 1992: Postgraduate degree in Oceanography, Meteorology and Environment (D.E.A. “océanologie, Météorologie et Environnement ”, Université Pierre et Marie Curie (Paris VI), France).

1990 – 1992: Degree in Land, Water and Forest Engineering. (Diplôme d’Ingénieur de l’Ecole Nationale du Génie Rural des Eaux et des Forets (ENGREF), Paris, France).

1988 – 1991: Degree in Agricultural Engineering (Diplôme d’Ingénieur Agronome de l’Institut National Agronomique de Paris-Grignon, France).

Scientific Publications

I have been involved in a wide range of environmental studies, focussed on various aspects of the carbon, water and energy cycles and including many collaborators across the world. I published over 110 papers in peer reviewed journals, including high profile journals (h-index of 40). As I still very much enjoy working on the nuts and bolts of models and numerical methods, I like to contribute to the technical aspects of the papers published by my students, post-docs and collaborators.

Full list of publications: Publication_list.docx

Selected list of publications:

• Peylin, P., Bacour, C., MacBean, N., Leonard, S., Rayner, P. J., Kuppel, S., Koffi, E. N., Kane, A., Maignan, F., Chevallier, F., Ciais, P., and Prunet, P. 2016. A new stepwise carbon cycle data assimilation system using multiple data streams to constrain the simulated land surface carbon cycle, Geoscientific Model Development, 9, 3321-3346.
• Barichivich, J., E. Gloor, P. Peylin, R. J. W. Brienen, J. Schöngart, J. C. Espinoza, K. C. Pattnayak, Recent intensification of Amazon flooding extremes driven by strengthened Walker circulation. Science Advances 4, eaat8785, 2018.
• Bacour, C., Peylin, P., MacBean, N., Rayner, P. J., Delage, F., Chevallier, F., Weiss, M., Demarty, J., Santaren, D., Baret, F., Berveiller, D., Dufrene, E., and Prunet, P. 2015. Joint assimilation of eddy covariance flux measurements and FAPAR products over temperate forests within a process-oriented biosphere model, Journal of Geophysical Research-Biogeosciences, 120, 1839-1857.
• Launois, T., Peylin, P., Belviso, S., and Poulter, B. 2015. A new model of the global biogeochemical cycle of carbonyl sulfide – Part 2: Use of carbonyl sulfide to constrain gross primary productivity in current vegetation models, Atmospheric Chemistry and Physics, 15, 9285-9312.
• Naudts, K., Ryder, J., McGrath, M. J., Otto, J., Chen, Y., Valade, A., Bellasen, V., Berhongaray, G., Boenisch, G., Campioli, M., Ghattas, J., De Groote, T., Haverd, V., Kattge, J., MacBean, N., Maignan, F., Merila, P., Penuelas, J., Peylin, P., Pinty, B., Pretzsch, H., Schulze, E. D., Solyga, D., Vuichard, N., Yan, Y., and Luyssaert, S. 2015. A vertically discretized canopy description for ORCHIDEE (SVN r2290) and the modifications to the energy, water and carbon fluxes, Geoscientific Model Development, 8, 2035-2065.
• Kuppel, S., Peylin, P., Maignan, F., Chevallier, F., Kiely, G., Montagnani, L., and Cescatti, A. 2014. Model-data fusion across ecosystems: from multisite optimizations to global simulations, Geoscientific Model Development, 7, 2581-2597.
• MacBean, N., and Peylin, P. 2014. Agriculture and the global carbon cycle, Nature, 515, 351-352, 2014.
• Santaren, D., Peylin, P., Bacour, C., Ciais, P., and Longdoz, B.: Ecosystem model optimization using in situ flux observations: benefit of Monte Carlo versus variational schemes and analyses of the year-to-year model performances, Biogeosciences, 11, 7137-7158, 10.5194/bg-11-7137-2014, 2014.
• Peylin, P., Law, RM., Gurney, K.R., Chevallier, F., Jacobson, A.R., Maki, T., Niwa, Y., Patra, P.K., Peters, W., Rayner, P.J., Rodenbeck, C., van der Laan-Luijkx, I.T., Zhang, X. 2013. Global atmospheric carbon budget: results from an ensemble of atmospheric CO₂ inversions, Biogeosciences, 10, 6699-6720.
• Cadule, P., Friedlingstein, P., Bopp, L., Sitch, S., Jones, C.D., Ciais, P., Piao, S.L., Peylin, P. 2010 Benchmarking coupled climate-carbon models against long-term atmospheric CO₂ measurements, Global Biogeochemical Cycles, 24, GB2016.
• Piao, SL; Fang, JY; Ciais, P; Peylin, P; Huang, Y; Sitch, S; Wang, T, The carbon balance of terrestrial ecosystems in China, NATURE, 458, 2009
• P. Peylin, P. Bousquet, S. Sitch, C. Lequere, P. Friedlingstein, P.Ciais, et P.Tans, Multiple constraints on regional CO2 flux variations over land and oceans, Global Bio. Cycle, 19, GB1011 FEB 10, 2005.
• P. Bousquet, P. Peylin, P. Ciais, C. Lequere, P. Friedlingstein, et P.Tans, Regional changes in carbon dioxide fluxes of land and oceans since 1980, Science, 290, 1342-1346, 2000.
• Peylin P., Ciais P., Denning A.S., Tans P.T., Berry J.A. and White J.W.C., A three-dimensional study of ¹⁸O in atmospheric CO₂ : contibution of different land ecosystem, Tellus, 51B, 642-667, 1999

Ongoing publications:

• Peylin, P., et al. The new ORCHIDEE land surface model version V2.0 as used for the CMIP6 climate simulation intercomparison exercice.
• Bastrikov et al., Land surface model parameter optimisation using in-situ flux data: comparison of gradient-based versus random search algorithms (a case study using ORCHIDEE v1.9.5.2)
• Bacour, C. et al., Differences between OCO2 and GOME2 SIF products from a model-data assimilation perspective.
• Druel et al., Modelling the dynamic of boreal shrubs and mosses in the ORCHIDEE land surface model: challenges and opportunities.
• Raoult et al., Confronting Soil Moisture Dynamics from the ORCHIDEE Land Surface ModelWith the ESA-CCI Product: Perspectives for Data Assimilation.
• Vuichard et al., Accounting for Carbon and Nitrogen interactions in the Global Terrestrial Ecosystem Model ORCHIDEE (rev 4999): multi-scale evaluation of gross primary production.