Julien Boucharel

Researcher IRD

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LITTORAL

MOANA : Océan Atmosphère multi-échelles

Address :

LEGOS-OMP, bureau D102
14 avenue Edouard Belin, 31400, TOULOUSE

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CV / functions

2022 – : Research scientist at the French National Research Institute for Sustainable Development (IRD), LEGOS, Toulouse, France.

2018 – 2023: Laureate of the French government’s fellowship “Make Our Planet Great Again”. LEGOS, Toulouse, France.

2016 – 2018: Research assistant at the department of Atmospheric Sciences at the University of Hawaii at Manoa, USA.

2014 – 2016: Research assistant at the Climate Change Research Center at the University of New South Wales at Sydney, Australia.

2011 – 2014: Postdoctoral fellow at the department of Atmospheric Sciences at the University of Hawaii at Manoa, USA.

2008 – 2011: PhD at LEGOS (Laboratoire d’Etudes en Géophysique et Océanographie Spatiales, University of Toulouse, France.) Reward grant from the French government (Department of Education and Research).

2006 – 2007: M.S. degree with honors at LEGOS, University of Toulouse, France. Reward grant from Midi-Pyrenees regional council (board of region).

2005 – 2006: Research experience in Peru

Involved in the creation and curriculum of a M.S. degree in numerical fluid dynamic at the University of San Marcos, Lima in collaboration with the college of engineering at the University of Toulouse(ENSEEIHT) and IMFT (Institute of Fluid Mechanics, Toulouse).

2004 – 2007: Graduate studies at ENSEEIHT, University of Toulouse, France. Major in fluid mechanics and hydraulic.

Research

My research focuses on three central scientific themes: the study of ENSO dynamical processes and teleconnections, tropical cyclone activity, and storm-induced coastal impacts, with the following key scientific objective:

UNDERSTANDING THE CONNECTIONS BETWEEN LARGE-SCALE CLIMATE VARIABILITY, STORM ACTIVITY AND COASTAL VULNERABILITY IN THE TROPICS

Specific research interests:

El Niño/Southern Oscillation (ENSO)
Tropical oceanography and meteorology
Climate change – global and regional impacts
Regional and coastal modeling
Statistical and mathematical tools for climate data analysis
Nonlinear dynamics – time scales interactions
Tropical Cyclones, climate control, dynamics and forecasting
Morphodynamics, Coastal erosion and flooding
Oceanic surface waves and storm activity
Biogeochemestry, Dynamics of the Oxygen Minimum Zone

Responsibilities

Active reviewers for various journals in the field: Journal of Climate, Tellus, Climate Dynamics, Ocean Modelling, Geophysical Research Letters, Science, Nature Communications, Scientific Report, Atmospheric Science Letters, Journal of Climate, International J. of Climatology…
Chair of the session “Atmospheric teleconnection processes” at the CSHOR ENSO science symposium held in Hobart in January 2019.
Main organizer of an international workshop on “the complexity and diversity of ENSO and its global impacts” held in Toulouse in September 2019 and October 2024.
Member of the scientific and steering committees of the MOPGA panel and international conferences held in Strasbourg (November 2021) and in Berlin (December 2022).
Convener of the session “New Challenges for Earth System Modeling” at the MOPGA conference in Berlin (December 2022).

Publications

Graffin, M., R. Almar, E. Bergsma, J. Boucharel, S. Vitousek, M. Taherkhani, and P. Ruggiero, Waterline responses to climate forcing along the North American West coast. In review in Communications Earth & Environment (2025).

Boucharel, J., R. Almar, F-F Jin, S. Zhao, M. Stuecker and B. Dewitte, Skillful seasonal predictions of coastal risks from climate modes interactions. In review in Nature Geoscience (2025).

Arias, A., R. Almar, J.Boucharel and V. Regard, Multifaceted ENSO impact on coastal risks across the Pacific. In review in Environmental Research Letters (2025).

Wongchuig S., F. Papa, A. S. Fleischmann, J.P Sierra, J. Boucharel, J.C. Espinoza, B. Kitambo, R.M. Tshimanga, R. Jucá Oliveira, A. Paris, R. Paiva and. P. Casas, Recent significant drying in the Central Congo Basin linked to the weakening of the Walker circulation in a warmer Atlantic. In review in npj Climate and Atmospheric Science (2025).

Xue, A., S. Stevenson, J. Boucharel, F-F. Jin, W. Zhang, M. Wang, Tropical Instability Wave-Induced Feedbacks Modulate the Tropical Pacific Response to Greenhouse Warming. Revised for Nature Communications (2025).

Richards, C., et al, Addressing global environmental challenges requires interdisciplinary science programs: Lessons learned from the Franco-German « Make Your Planet Great Again » (MOPGA) initiative. Revised for Proc. Natl. Acad. Sci. USA, (2025).

Almar, R., J. Boucharel, A. Murray, E. Anthony, G. Abessolo, G. Thoumyre, E. Bergsma, M. Graffin, P. Marchesiello, Detection of self-evolving regional propagating shoreline features worldwide, In revision in Nature Geoscience, (2025).

Almar, R., Boucharel J., R. G. Abessolo, M. Graffin, G. Thoumyre, F. Papa, E. Bergsma, E. Anthony, A. Melet and V. Regard, Global patterns of climate-driven coastal shoreline variability reveal the importance of total water level, Revised for J. Geophys. Res. Oceans, (2025).

Escobar Franco, M. G., J. Boucharel, and B. Dewitte, Interaction between intraseasonal equatorial Kelvin waves and tropical instability waves in a tropical Pacific model simulation, In revision in J. Phys. Oceanogr., (2025).

Jiang, F., Zhang, W., Boucharel, J., Jin, F.‐F., McPhaden, M. J., & Stuecker, M. F., Multi‐season lead prediction of Atlantic Niño facilitated by Pacific Ocean precursors. Geophysical Research Letters, 52, e2024GL111494. https://doi.org/10.1029/2024GL111494, (2025)

Holmes, R. M., L. Renault, L. Maillard, and J. Boucharel, Air-sea coupling feedbacks over Tropical Instability Waves. J. Phys. Oceanogr., https://doi.org/10.1175/JPO-D-24-0010.1, (2024).

Almar, R., Boucharel J., R. G. Abessolo, G. Thoumyre, F. Papa, E. Bergsma, Reply to: Coastal shoreline change assessments at global scale. Nature Communications, https://doi.org/10.1038/s41467-024-46609-w, (2024).

Boucharel J., R. Almar, and B. Dewitte, Seasonal forecasts of the world’s coastal waterline: what to expect from the coming El Niño? npj Climate and Atmospheric Science, 7:37 ; https://doi.org/10.1038/s41612-024-00570-z, (2024).

Jiang F., W, Zhang, J. Boucharel, F-F Jin, Tropical origins of the Pacific Meridional Mode associated with the nonlinear interaction of ENSO with the annual cycle, https://doi.org/10.1029/2023GL106225, Geophysical Research Letters, 50 (24), e2023GL106225, (2023).

Wongchuig S., B. Kitambo, F. Papa, A. Paris, A. Santos Fleischmann, L. Gal, J. Boucharel, R. Paiva, R. Jucá Oliveira, R.M. Tshimanga, S. Calmant, Improved modeling of Congo’s hydrology for floods and droughts analysis and ENSO teleconnections. J. Hydrology, 50, https://doi.org/10.1016/j.ejrh.2023.101563, (2023).

Liu, F., W. Zhang, F.-F. Jin, F. Jiang, J. Boucharel, and S. Hu, New insight into multi-year La Niña dynamics from the perspective of a near-annual ocean process. J. Climate, https://doi.org/10.1175/JCLI-D-22-0505.1, (2023).

Jiang F., W, Zhang, F-F Jin, M.F. Stuecker, A. Timmermann, M.J. McPhaden, J. Boucharel, and A. Wittenberg, Resolving the tropical Pacific/Atlantic interaction conundrum. Geophysical Research Letters, 50, e2023GL103777, https://doi.org/10.1029/2023GL103777, (2023).

Almar R., J. Boucharel, M. Graffin, R. G. Abessolo, G. Thoumyre, F. Papa, R. Ranasinghe, E. Bergsma, M. Baba and F.-F Jin, Influence of El Niño on the variability of global shoreline position. Nature Communications 14, 3133, https://doi.org/10.1038/s41467-023-38742-9, (2023).

Boucharel J, M. David, R. Almar and A. Melet, Contrasted influence of climate modes teleconnections to the interannual variability of sea level components – Implications for statistical forecasts. Climate Dynamics, https://doi.org/10.1007/s00382-023-06771-1, (2023)

Xue, A., F.-F. Jin, W. Zhang, J. Boucharel, and J.-S. Kug, Parameterizing the nonlinear feedback on ENSO from Tropical Instability Waves (TIWs) by Nonlinear Eddy Thermal Diffusivity. Climate Dynamics, https://doi.org/10.1007/s00382-023-06744-4, (2023).

Maillard, L., J. Boucharel, M.F. Stuecker, F.-F. Jin, and L. Renault, Modulation of the eastern equatorial Pacific seasonal cycle by tropical instability waves. Geophysical Research Letters, 49, e2022GL100991, https://doi.org/10.1029/2022GL100991, (2022).

Maillard, L., J. Boucharel, and L. Renault, Direct and rectified Tropical Instability Waves effect onto the Eastern tropical Pacific mean state in a regional ocean model. J. Phys. Oceanogr., DOI:https://doi.org/10.1175/JPO-D-21-0300.1, (2022).

Escobar Franco, M. G., J. Boucharel, and B. Dewitte, On the relationship between Tropical Instability Waves and the intraseasonal Kelvin waves in the Pacific from satellite observations (1993-2018). Front. Mar. Sci., 9, https://doi.org/10.3389/fmars.2022.788908, (2022).

Boucharel J, L. Santiago, and R. Almar, Coastal wave extremes around the Pacific and their remote connection to climate modes, Climate, 9, 168, https://doi.org/10.3390/cli9120168, (2021).

Boucharel, J., R. Almar, E. Kestenare, and F.-F. Jin, On the influence of ENSO complexity on Pan-Pacific coastal wave extremes. Proc. Natl. Acad. Sci. USA, 118, e2115599118, https://doi.org/10.1073/pnas.2115599118, (2021).

Xue, A., W. Zhang, J. Boucharel, and F.-F. Jin, Anomalous Tropical Instability Wave activity hindered the development of the 2016/2017 La Niña. J. Climate, 34(13), 5583-5600, https://doi.org/10.1175/JCLI-D-20-0399.1, (2021).

Marchesiello, P., E. Kestenare, R. Almar, J. Boucharel, N.M. Nguyen, Longshore drift produced by climate-modulated monsoons and typhoons in the South China Sea. J. Mar Sys., 111, 103399, https://doi.org/10.1016/j.jmarsys.2020.103399, (2020).

Xue, A., F.-F. Jin, W. Zhang, J. Boucharel, S. Zhao, and X. Yuan, Delineating the seasonally modulated feedback onto ENSO from the Tropical Instability Wave activity. Geophys. Res. Lett.,47, e2019GL085863.https://doi.org/10.1029/2019GL085863, (2020).

Boucharel, J. and F.-F Jin, A simple theory for the modulation of Tropical Instability Waves by ENSO and the annual cycle. Tellus A, 72(1), 1-14, https://doi.org/10.1080/16000870.2019.1700087, (2020).

Almar, R., E. Kestenare and J. Boucharel, On the key influence of the remote climate variability from Tropical Cyclones, North and South Atlantic mid-latitude storms on the Senegalese coast (West Africa). Env. Res. Comm., 1-7, https://doi.org/10.1088/2515-7620/ab2ec6, (2019).

Huang, S.-C., J. Boucharel, I-I. Lin, I.F. Pun, and F.-F. Jin, Air-sea fluxes for Hurricane Patricia (2015): Comparison with supertyphoon Haiyan (2013) and under different ENSO conditions . J. Geophys. Res. Oceans, 122, 6076-6089, https://doi.org/10.1002/2017JC012741, (2017).

Boucharel, J., F.-F. Jin, M.E. England, and I.-I. Lin, Modes of hurricane activity variability in the Eastern Pacific: implications for the 2016 season. Geophys. Res. Lett., 43, https://doi.org/10.1002/2016GL070847, (2016)

Boucharel, J., F.-F. Jin, M.E. England, B. Dewitte, I.-I. Lin, S.-C. Huang, and M. A. Balmaseda, Influence of intraseasonal oceanic Kelvin waves on the Eastern Pacific hurricane activity. J. Climate, https://doi.org/10.1175/JCLI-D-16-0112.1, (2016).

Boucharel, J., F.-F. Jin, I.-I. Lin, S.-C. Huang, and M. H. England, Oceanic versus Atmospheric Control of Tropical Cyclone Activity in the Eastern Pacific for two types of El Niño. Geophys. Res. Lett., 43, https://doi.org/10.1002/2016GL067728, (2016)

Jin, F.-F., J. Boucharel, and I.I. Lin, Reply to Moon, I. J., Kim, S. H. & Wang, C. Nature 526, http://dx.doi.org/10.1038/nature15547, (2015).

Boucharel, J., A. Timmermann, A. Santoso, M. H. England, F.-F. Jin, and M. A. Balmaseda, A surface layer variance heat budget for ENSO. Geophys. Res. Lett., 42, https://doi.org/10.1002/2015GL063843, (2015).

Jin, F.-F., J. Boucharel, and I. I. Lin, Eastern Pacific Tropical Cyclones intensified by El Niño delivery of subsurface ocean heat, Nature, 516, 82–85, https://doi.org/10.1038/nature13958, (2014).

Illig, S., B. Dewitte, K. Goubanova, G. Cambon, J. Boucharel, F. Monetti, C. Romero, S. Purca, and R. Flores, Forcing mechanisms of intraseasonal SST variability off central Peru in 2000-2008. J. Geophys. Res. Oceans, 119, 3548–3573, https://doi.org/10.1002/2013JC009779, (2014).

Boucharel, J., A. Timmermann, and F.-F. Jin, Zonal phase propagation of ENSO SST anomalies – revisited. Geophys. Res. Lett. https://doi.org/10.1002/grl.50685, (2013).

Boucharel, J., Dewitte, B., du Penhoat, Y., Yeh, S.-W., Kug, J.-S., and B. Garel, ENSO nonlinearity in a warming climate. Clim. Dynam., 37, 2045-2065, https://doi.org/10.1007/s00382-011-1119-9, (2011).

Boucharel, J., Dewitte, B., Garel, B., and Y. du Penhoat, ENSO’s nonstationary and non-Gaussian character: the role of climate shifts. Nonlin. Proc. Geophys. 16, 453-473, https://doi.org/10.5194/npg-16-453-2009, (2009).

Book chapters:

Lin, I-I, S. Camargo, C. Patricola, J. Boucharel, S. Chand, P. Klotzbach, J. Chan, B. Wang, P. Chang, T. Li, Chapter “ENSO and Tropical Cyclones”. In El Niño Southern Oscillation in a Changing Climate (eds M. McPhaden, A. Santoso, W. Cai). American Geophysical Union. 253, 377 pp., https://doi.org/10.1002/9781119548164.ch17, (2020).

Du Penhoat, Y., and J. Boucharel, Nonlinearity as a key player for ENSO modulation: What do the climate models tell us? “Climate variability in the Tropical Pacific: Mechanisms, modelling and observations”, Edited by Y. du Penhoat and A.V. Kislov, Moscow, Maks-Press(2010).

Others (in French or Spanish):

Boucharel, J., 2018: Influencia de la dinámica oceánica relacionada al ENSO en la modulación de la actividad de los Ciclones Tropicales en el Pacífico Oriental. Boletín Técnico del Instituto Geofísico del Perú, Vol. 5, 2018.

Boucharel, J., 2010: Modes de variabilité climatique dans l’océan Pacifique tropical: quantification des non-linéarités et rôle sur les changements de régimes climatiques. PhD dissertation. Université Paul Sabatier, Toulouse III; 305pp, (https://theses.hal.science/tel-00720706/document).

CNRS-INSU newsletter: “Vers une quantification du comportement chaotique d’ENSO” : http://www.insu.cnrs.fr/a3110,vers-quantificationcomportement-chaotique-el-nino.html

Projects

co-Investigator on «Quantifying and Understanding Marine Biogeochemistry-ENSO Interactions & Feedbacks in Earth System Models»

Source of Support: DoE, Award Requested: k$775; Requested Period: 2025 – 2027

Principal-Investigator on « ENSOMETRY: The high-resolution ENSO: dynamics and future projections »

Source of Support: ANR (French NSF), Award Requested: €642,000; Requested Period: 09/2025 – 08/2029

Coordinator of work package 1 on the « Climate Change flagship program » whose objective is « to develop a free and open data set of comprehensive climate change projections (oceanic and atmospheric) for all Pacific countries and territories ».

Source of Support: New Zealand Ministry of Foreign Affairs and Trade, delegated to IRD, €1,142,960; Award Period: 01/2024 – 12/2026

Co-Principal-Investigator. « Developing dynamically constrained projections of ENSO activity and associated coastal hazards – An application to the Hawaiian and US-affiliated Pacific Islands» 2023-2026

PI: Prof. Fei-Fei Jin. Source of Support: NOAA-MAPP: Climate Futures: Projections for Societally-Relevant Problems, Award Amount: $597,833; Award Period: Sep 2023 – Aug 2026

Co-Investigator and science team member « CFOSAT-LAGOON: Waves in barrier reef environments, from the deep ocean to the lagoon »

PI: Dr. Rafael Almar. Source of Support: French Space Agency (CNES), Award Amount: €117,100; Award Period: Feb 2023 – Jan 2026

Principal-Investigator on «MUSIC: MUlti Scale Interactions in the PacifiC – Development of Tropical Instability Waves parameterizations for Earth System Models »

Source of Support: Thomas Jefferson Fund & FACE Foundation, Award Amount: k$20; Award Period: 09/01/2021 – 08/31/2023

Co-Investigator on «VENUS: wave-atmosphere-ocean oVer wEsterN boundary CurrentS ».

PI: Dr. Lionel Renault. Source of Support: AO INSU LEFE, Award Amount: ~k€18; Award Period: 01/03/2021 – 02/29/2023

Co-Investigator on «CLAP: CLimate Action Planning».

PI: Dr. Boris Dewitte. Source of Support: ANID (Agencia Nacional de Investigación y Desarrollo, Chilean NSF), 2021-2025

Principal-Investigator on «TROCODYN: TROpical Cyclone activity and upper-Ocean DYNamics».

Source of Support: ANR (French NSF) Make Our Planet Great Again (MOPGA); Total Award Amount: €1,018,506; Award Period: 09/01/2018 – 08/31/2022

Co-Investigator on « Studies of Dynamics for ENSO Diversity and Complexity ». PI: Prof. Fei-Fei Jin; Source of Support: NSF; Total Award Amount: $599,778; Award Period: 08/15/2018 – 07/31/2021

Teaching

Mentoring:

Main supervisor:

Harold Diaz, PhD (2023-2026): Connection between offshore wave forcing and coastal water level: towards improved parameterizations of wave run-up and flooding warning systems (co-supervisor: Y. Soufflet)
Carlos Conejero, Post-doc (2023-2026): Influence of mesoscale oceanic activity and air-sea interactions on ENSO and its storm related impacts (co-supervisor: L. Renault)
Alexandre Barboni, Post-doc (2023-2026): Marine Heat Waves in French Polynesia (co-supervisor: L. Renault)
Lisa Maillard, PhD (2019-2022): Influence of the upper ocean stratification on Tropical Cyclone activity in the Eastern Pacific at sub-seasonal to seasonal timescales (co-supervisor: L. Renault)
Maria Gabriela Escobar Franco, PhD (2019-2022): Intraseasonal interactions in the equatorial Pacific Ocean (Co-supervisor: B. Dewitte)
Feng Jiang, PhD (2022): Multiscale interaction in the Eastern equatorial Pacific: the influence of ENSO complexity on the Tropical Instability Waves biological pump. (Chinese Research Council fellowship to visit LEGOS for one year)
Loïc Macé, MSc (2021): The influence of ENSO on tropical vs. extra-tropical storms contributions to coastal sea-level in the Eastern Pacific (co- supervisor: L. Renault)
Loane Santiago, MSc (2021): The influence of ENSO on global coastal wave (co-supervisor: R. Almar)
Juliette Deman, MSc (2021): Modeling study of Tropical cyclone NIRAN (co-supervisor: R. Benshila)

Co-supervisor:

Marjorie David, MSc (2021): Assessing sea-level contributions to over-topping conditions in the Pacific (main supervisor: A. Melet).

Marcan Graffin, MSc (2021): Connections between modes of climate variability and shoreline variability (main supervisor: R. Almar).

Scientific committee:

Aude Carreric, PhD (2015-2019): Main advisors: B. Dewitte, V. Guemas
Aoyun Xue, PhD (2018-2022): Main advisors: F.-F. Jin, W. Zhang
Hsiao-Ching Huang, PhD (2015-2018): Main advisor: I.I Lin
Amélie Arias, PhD (2023-2026): Main advisors: R. Almar, V. Regard
Marcan Graffin, PhD (2023-2026): Main advisors: R. Almar, E. Bergsma

Teaching:

University of San Marcos Lima, Peru: Teaching assistant for Undergraduate studies: mathematics, fluid mechanics, English, French (2005-2006) (~50 hours).

IMARPE, Lima, Peru: Training of the faculty staff members at the newly created local modeling center CIMOBP (regional ocean model ROMS) (2007-2008) (~25h).

University of Toulouse (ENSEEIHT), France: Teaching assistant for Graduate studies: Elaboration and teaching of free surface hydraulic lab class (2007-2008) (~15h) and “Statistics and Probability” class (2008-2009) (~20h).

Julien Boucharel

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