We mostly study fluid dynamical processes in the context of the ocean, principally via computational methods. While the motivating context is on global/regional settings and we touch on climate/biogeochemistry/ecology/modelling applications, the focus is on the physical processes. On this site you can find information about our research projects (which also includes some non-ocean things we do), and the members making it happen.

Our research activities are funded by the RGC, QNLM through the CORE program, and Hong Kong Branch of SMSEGL (Guangzhou). Those interested in joining the group as a student/staff are generally welcome to contact Julian Mak, no guarantees we have openings though (we are essentially fully committed in terms of time and money at this present time). If you are looking for short projects (e.g. UG or MSc students, doesn't have to be within ocean science department itself), then please see blurb at this link.


Congratulations to Han Seul who has been awarded a Korean government scholarship to be an intern at the World Meteorological Organization, to be based in Geneva. See you in six months!

Julian gave an outreach talk at Sha Tin College on 6th December 2021 as part of the Ocean Week event at the school.

The group was funded by the HK RGC on probing South China Sea circulation via state estimates (grant number 16304021). Watch this space for outputs in due course.

Recent misc. outputs

On constraining the mesoscale eddy energy dissipation time-scale

J. Mak, A. Avdis, T. W. David, H. S. Lee, Y. Na, Y. Wang & F. E. Yan [preprint]
submitted to J. Adv. Model. Earth. Syst.

Acute sensitivity of global ocean circulation and heat content to eddy energy dissipation time-scale

J. Mak, D. P. Marshall, G. Madec & J. R. Maddison (2022) [doi]
Geophys. Res. Lett., 49(8), e2021GL097259

Zero absolute vorticity plane Couette flow as an hydrodynamic representation of quantum energy states under perpendicular magnetic fields

E. Heifetz, L. R. M. Maas & J. Mak (2021) [doi]
Phys. Fluids, 33(12), 127120

On a formal equivalence between electro-magnetic waves in cold unmagnetized plasma and shallow water inertio-gravity waves

E. Heifetz, L. R. M. Maas, J. Mak & I. Pomerantz (2021) [doi]
J. Phys. Commun., 5(12), 125006

Distinct interaction effects of warming and anthropogenic input on diatoms and dinoflagellates in an urbanized estuarine ecosystem

Y. Y. Cheung, S. Cheung, J. Mak, K. Liu, X. Xia, X. Zhang, Y. Yung & H. Liu (2021) [doi]
Glob. Change Biol., 27(15), 3463-3473

Research Areas


Eddy parameterisation

One of the focus of the group is on mesoscale eddy parameterisation arising from baroclinic turbulence, particularly on the energetically constrained parameterisation GEMOETRIC. Research activities include evaluating the impact on the modelled ocean circulation, on constraining the unknown parameters/processes associated with eddy energetics, and on maintaining/developing/implementing the relevant codes in global circulation models.

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Inverse methods / state estimates

We deploy and develop code/models for tackling optimisation, inference and/or data assimilation problems in the ocean context. Current activities including constraining uncertain parameters associated with eddy energy constrained parameterisations, inference of uncertain physical processes in the South China Sea, employing both the Firedrake and MITgcm ECCO framework. Outlooks include uncertainty quantification and biogeochemical applications.

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Chaotic / turbulent stirring

Stirring (to highlight the central role played by advection) of tracers is intimately linked to eddy parameterisations, as well as having implications for modelling biogeochemistry, ecology and pollutant dispersion. We are particularly interested in the Lagrangian point of view for dispersion, in quantifying dispersion via methods in dynamical systems and/or more recent Bayesian methods, and the associated computational methods.

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Theoretical fluid dynamics (mostly GFD, some MHD)

A focus we have is on baroclinic lifecycles, baroclinic turbulence, wave/eddy-mean interaction and shear flow instabilities to complement the modelling work on eddy parameterisation. Current work involves employing optimisation principles in relation to baroclinic equilibration, baroclinic instabilities under the GEOMETRIC framework, as well as symmetry breaking in waves and instabilities.

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Current team




Supervisor and spiritual leader.


Julian Mak

Assistant Professor + code monkey

The group's code-fixer. See personal website for proper content.

Favourite fish: Ducks

Han Seul

Han Seul Lee

PhD student (from Sep 2020)

Han Seul is currently researching the South China Sea circulation, using a finite element method that utilises Firedrake. Her fascination is with simple models, and the degree to which they do (and do not) reflect the real world. She received her MPhys degree from the University of Oxford, where she studied the Antarctic Circumpolar Current using an eddy-parameterizing model, looking at different parameterization schemes.


Ruan Xi (阮曦, Bobo)

MSc student (Jan - Jun 2020), PhD student (from Sep 2020; with Alex Wyatt)

here be tumbleweeds...


Yongsu Na

PhD student (from Sep 2020)

Yongsu's main interest is a clear understanding of the natural phenomena associated with the ocean. He received his BSc and MEng from Korea University. He worked with Prof. Sangyoung Son on storm surge prediction using Delft3D and tropical cyclone prediction using echo state networks. He is currently working on the ocean mesoscale eddy parameterization using inverse methods and MITgcm. Along with his research, he enjoys playing sports (football, swimming, gym training) and skateboarding.


Liu Yongqi (劉詠琪)

Doraemon + MPhil student (from Sep 2020; with Wang Yan)

Yongqi obtained her BSc Degree in Marine Science from Guangdong Ocean University in 2020. Her undergraduate study involved the study of mesoscale eddies, and she is interested in the area of the Southern Ocean. In the days to come, she will work on slope dynamics and energetics in the Southern Ocean.


Yan Feier (嚴菲兒)

PhD student (from Feb 2021)

Feier's research interest is on the applications of machine learning methods to understanding oceanic mesoscale eddies. Feier obtained a MSc degree in Environmental fluid mechanics from the University of Grenoble Alpes, and another in Physical oceanography from the University of Bretagne Occidentale, France. Hobbies include swimming and hiking, undertaking a long-distance trail at least once a year.


Gautam Kumar

Post-doctoral Research Assistant (from Mar 2021)

Gautam worked as a research associate (May 2020-Nov 2020) at IIT Hyderabad and (Dec 2020 - Feb 2021) at IIT Gandhinagar before joining HKUST as a Postdoctoral Fellow. He received a Ph.D. degree in applied mathematics from IIT Hyderabad in 2020. He concentrated on convection in porous media, carbon sequestration, and electrohydrodynamics during his Ph.D. He is now working on the problems related to "inertial gravity waves and their interaction.


Dan Bartley

Research Assistant (from Jan 2022)

Dan’s research interest lies in the physical interactions between natural environments and engineering interventions. He obtained a MEng degree in Civil Engineering from Imperial College London and has research experience in sediment transport, wetland management and artificial reefs. After work, Dan’s hobbies include hiking, video games and making music.

Dearly departed


Haruki Saegusa
(Jul 21 - Feb 22)
UG researcher
Student at HKUST


Floriane Océane Sudre
(Mar 20 - May 21)
RA + PhD
Position in Marseille


Chinmayee Mallick
(May 20 - Mar 21)
Research Assistant
Research Assistant at PolyU


Ellie Ong
(Oct 20 - Jan 21)
Visiting scholar


(Jun 18 - Jun 19)
Streetcat, stayed in Oxford


(Feb 18)
Honourary member