Hao Zuo

Visiting Scientist
Research Department, Earth System Assimilation Section, Coupled Assimilation Group

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Hao Zuo is responsible for Ocean (Re)Analysis System at ECMWF. He implements and maintains the operational Ocean (Re)Analysis System-OCEAN5 and  is one of the main developer for NEMOVAR Ocean Data Assimilation System at ECMWF. Ocean analysis is used to initialize the ocean and sea-ice components of all ECMWF coupled forecasting systems, as well as the new seasonal forecasting system (S5). Hao is also in charge of integrating ocean observations (in-situ, SST, sea ice, SSH) into the ECMWF System for Earth System assimilation and carrying out Observing System Experiments for impact studies. This work is part of the AtlantOS project funded by EU Horizon 2020 and CCI Sea Level project funded by European Space Agency (ESA). He focuses on research topics like study of climate signals  using Ocean Reanalysis products and observations, including changes/trends in sea-level, sea ice cover and  ocean overturning circulations.

Professional interests: 

My research interests include

  • Ocean reanalysis for climate applications and for initialization of seasonal forecasting system
  • Observations and ensemble data assimilation
  • Climate change and signals derived from reanalysis and observations
  • Ocean overturning circulation and mixing process.
  • Heat content and freshwater budget in the ocean
Career background: 


  • Ph.D., 2005-2009, Physical Oceanography, National Oceanography Centre,  University of Southampton, U.K.
  • Visiting student, 2007, Woods Hole Oceanography Institution, U.S.
  • M.Sc., 2003-2005, Physical Oceanography, Nanjing University, China
  • Linnaeus-Palme visiting student, 2004, Department of Hydrography, Uppsala University, Sweden
  • Bachelor degree, 1999-2003, Physical Geography, Nanjing University, China

Professional Experience

  • Since 07/2012: Scientist, ECMWF Research Department, Marine Prediction Section and Earth System Assimilation Section
  • 11/2009-07/2012: IPY Arctic research Fellow, University of Reading,  Environmental Systems Science Centre.
External recognitions: 
  • 2008: Young Scientist Outstanding Poster Award in EGU General Assembling in Vienna.
  • 2016: GODAE OceanView Observing System Evaluation Task Team (OSEval_TT)

Peer-reviewed publications

  • Legeais, J.-F., Cazenave, A., Ablain, M., Zawadzki, L., Zuo, H., Johannessen, J.A., Scharffenberg, M. G., Fenoglio-Marc, L., Fernandes, M.J., Andersen, O., Rudenko, S., Cipollini, P., Quartly, G., Passaro, M., Benveniste, J., 2017. An Accurate and Homogeneous Altimeter Sea Level Record: the Reprocessed ESA Essential Climate Variable. Nature Scientific Data, in preparation.
  • Chevallier. M. Smith, G., Dupont, F., Lemieux, JF, Forget, G., Fujii. Y., Hernandez, F., Msadek, R., Peterson, KA., Storto, A., Toyoda, T., Valdivieso, M., Vernieres, G., Zuo, H. and et al., 2016. Intercomparison of the Arctic sea ice cover in global ocean-sea ice reanalyses from the ORA-IP project. Climate Dynamics, 10.1007/s00382-016-2985-y.
  • Zuo, H., Balmaseda, M. A. and Mogensen, K., 2015. The new eddy-permitting ORAP5 ocean reanalysis: description, evaluation and uncertainties in climate signals. Climate Dynamics, 49(3), 791-811, doi:10.1007/s00382-015-2675-1
  • Tietsche, S., Balmaseda, M. A., Zuo, H. and Mogensen, K., 2015. Arctic sea ice in the global eddy-permitting ocean reanalysis ORAP5. Climate Dynamics, 10.1007/s00382-015-2673-3 
  • Masina, S., Storto, A., Ferry, N., Valdivieso, M., Haines, K., Balmaseda, M., Zuo, H., Drevillon, M. and Parent, L., 2015. An ensemble of eddy-permitting global ocean reanalyses from the MyOcean project. Climate Dynamics, pp.1-29.
  • Toyoda, T, Fuj, ii, Y, Kuragano, T, Kosugi, N, Sasano, D, Kamachi, M, Ishikawa, Y, Masuda, S, Sato, K, Awaji, T, Hernandez, F, Ferry, N, Guinehut, S, Martin, MJ, Peterson, KA, Good, SA, Valdivieso, M, Haines, K, Storto, A, Masina, S, Köhl, A, Yin, Y, Shi, L, Alves, O, Smith, G, Change, Y-S, Verniers, G, Wang, XL, Forget, G, Heimbach, P, Wang, O, Fukumori, I, Lee, T, Zuo, H, Balmaseda, MA., 2015. Interannual-decadal variability of wintertime mixed layer depths in the North Pacific detected by an ensemble of ocean syntheses. Climate Dynamics, 1-17.
  • Toyoda, T, Fuj, ii, Y, Kuragano, T, Kamachi, M, Ishikawa, Y, Masuda, S, Sato, K, Awaji, T, Hernandez, F, Ferry, N, Guinehut, S, Martin, MJ, Peterson, KA, Good, SA, Valdivieso, M, Haines, K, Storto, A, Masina, S, Köhl, A, Zuo, H, Balmaseda, MA, Yin, Y, Shi, L, Alves, O, Smith, G, Change, Y-S, Verniers, G, Wang, XL, Forget, G, Heimbach, P, Wang, O, Fukumori, I, Lee, T, 2015.    Intercomparison and validation of the mixed layer depth fields of global ocean syntheses. Climate Dynamics, 10.1007/s00382-015-2637-7
  • Valdivieso, M., Haines, K., Zuo H., Lea, D., 2014, Freshwater and Heat transports from global ocean synthesis. Journal Geophys. Res., 119.
  • Roberts, C. D., Waters, J., Peterson, K. A., Palmer, M. D., McCarthy, G. D., Frajka-Williams, E., Haines, K., Lea, D. J., Martin, M. J., Storkey, D., Blockley, E. W. and Zuo H., 2013, Atmosphere drives recent interannual variability of the Atlantic meridional overturning circulation at 26.5 N. Geophys. Res. Lett., doi: 10.1002/grl.50930
  • Haines K., Stepanov V. N., Valdivieso M. and Zuo H., 2013, Atlantic meridional heat transports in two ocean reanalyses evaluated against the RAPID array, Geophys. Res. Lett., 40, 343–348, doi:10.1029/2012GL054581
  • Haines, K., Valdivieso, M., Zuo, H., and Stepanov, V. N., 2012, Transports and budgets in a 1/4° global ocean reanalysis 1989–2010, Ocean Sci. Discuss., 9, 333-344, doi:10.5194/os-8-333-2012
  • Zuo, H., Naveira Garabato, A., New, A., Oschlies, A., 2012, Mechanisms of Subantarctic Mode Water upwelling in a hybrid-coordinate global GCM, Ocean Modelling, Volumes 45–46, Pages 59-80, http://dx.doi.org/10.1016/j.ocemod.2011.12.006
  • Stepanov, V. N., Zuo, H., Haines, K., 2012, The link between the Barents Sea and ENSO events reproduced by NEMO model, Ocean Sci. Discuss., 9, 2121-2151, doi:10.5194/osd-9-2121-2012.
  • Zuo, H., Mugford, R. I., Haines, K., Smith, G. C., 2011, Assimilation impacts on Arctic Ocean circulation, heat and freshwater budgets, Ocean Modelling 40(2): 147-163, http://dx.doi.org/10.1016/j.ocemod.2011.08.008
  • Zuo, H. Shu, G., 2005, Simulation of Flooding Process in BOAO Harbor, Hainan Island, Marine Science Bulletin 24(1): 8-17.

Other publications

  • Le Traon, P. Y., et al., 2017. The Copernicus Marine Environmental Monitoring Service: main scientific achievements and future prospects. Mercator Ocean Newsletter - special Copernicus Marine Service Issue
  • Tietsche, S., Balmaseda, M. A., Zuo, H., 2017.  Monitoring thin sea ice in the Arctic. ECMWF Newsleter No. 152
  • Rosnay, P. de, Pappenberger, F., Zuo, H., Mallas, I., 2017. ECMWF-CMEMS agreement on sea-level anomaly data. ECMWF Newsletter No. 151
  • Tietsche, S., Balmaseda, M. A., Zuo, H., Rosnay,  P. de, 2017. Comparing Arctic winter sea-ice thickness from SMOS and ORAS5 ECMWF Tech Memo (803)
  • Zuo, H., Balmaseda, M. A., Boisseson, E., Hirahara, S., 2017.  A new ensemble generation scheme for ocean reanalysis. ECMWF Tech Memo (795)
  • Abdalla, S., Zuo, H., 2016. The use of radar altimeter products at ECMWF. ECMWF Newsletter No. 149
  • Zuo, H., Balmaseda, M. A., and Mogensen, K., 2014. The ECMWF-MyOcean2 eddy-permitting ocean and sea-ice reanalysis ORAP5. Part 1: Implementation. ECMWF Tech Memo (736)
  • Tietsche, S, Balmaseda, M. A, Zuo, H, Mogensen, K. 2014. Arctic sea ice in the ECMWF MyOcean2 ocean reanalysis ORAP5. ECMWF Tech Memo (737)
  • Valdivieso, M., Haines, K., Zuo, H., 2011, Scientific Validation Report (ScVR) for V2 Reprocessed Analysis and Reanalysis. GMES Marine Core Services Technical Report WP04-GLO-U-Reading.
  • Helene Hewitt, Jeff Ridley, Ann Keen, Alex West, Alison McLaren, Richard Wood and Drew Peterson, Seymour Laxon and Katharine Giles, Keith Haines and Hao Zuo, 2011 Does PIOMAS tell us anything to change the current MOHC view on Arctic sea ice extent decline? DECC Technical report.
  • Smith, G. C., Haines, K., Bretherton, D., Gemmell, A., Mugford, R., Stepanov, V., Valdivieso, M. and Zuo, H., 2010, Ocean Reanalysis studies in Reading: Reconstructing Water Mass variability and Transports. Mercator Newsletter 36, 39-49.


thumbnail photo of Hao Zuo
Contact Details:
hao . zuoecmwf . int