Current Team
Sebastiaan Swart – Professor

Sebastian Swart_autumn.jpg

Seb’s research interests are focused on understanding the circulation and dynamics in the open ocean, particularly in the Southern Ocean. As a Wallenberg Academy Fellow at the University of Gothenburg, Sweden, he is investigating the main physical processes of the upper ocean and how these impact both regional and global climate. He employs remotely sensed satellite data and in situ observations from gliders, ships and profiling floats in remote & harsh ocean environments to test novel hypotheses related to submesoscale features, upper ocean stratification and mixed layer processes. He was previously head of a national facility called the South African Marine Engineering & Robotics Centre and now directs the new Swedish Centre for Ocean Observing Technology (SCOOT). This position spurred his activities in pioneering cutting-edge technology, namely gliders, to obtain high-resolution ocean observations that continue to this day. He has Co-Chaired the international Southern Ocean Observing System (SOOS) and the Southern Ocean Air-Sea Flux (SOFLUX) working group and is currently Co-Chair of the UN Ocean Decade Program & SCOR WG ‘OASIS’ – Observing Air-Sea Interactions Strategy.

Louise Biddle – Researcher


Louise is a researcher in the group at the University of Gothenburg. She is interested in understanding how freshwater fluxes can affect the upper ocean through mixing or stratification on submesoscales, using a combination of observations and simple ocean process models. Her research at the moment focuses on the marginal ice zone around the Greenwich Meridian, using seal data to extract valuable measurements of temperature and salinity from under the sea ice during winter. Louise also has experience using Seagliders to collect ocean observations: during ship-board operations, piloting and later analysis of the data. She is passionate about developing our current abilities for under ice observations (whether that’s glacial or sea ice)!

See full CV

Marcel du Plessis – Marie Curie Research Fellow
IMG_5618 copy

Marcel is Marie Skłodowska Curie research fellow with the SPICE project (funded 2021-2023) in the group at the University of Gothenburg, with ongoing collaborations with CSIR, S Africa, Northern Ireland University of Galway and École Normale Supérieure in Paris. He is also working in the SO-CHIC Project.

He has a particular interest in combining ocean observations and modeling to understand how lower atmospheric processes, such as direct ocean heating/cooling and storms affect the surface ocean, eddies, currents, and mixing at the submesoscales.

He is currently investigating how storms impact the air-sea heat flux in the subpolar Southern Ocean to understand how this region, which is critial for absorbing anthropogenic heat and carbon, mitigates the effects of climate warming. He is primarly using observations from ocean gliders, but complements these with data from profiling floats, shipboard measurements, satellite observations, and model reanalyses. These provide information on the lower atmosphere, sea surface and ocean interior, which contains the link between coupled ocean and atmospheric exchanges. His future work will aim to investigate these processes using the PWP 1-D, NEMO 3-D and idealised PSOM (Mahadevan, WHOI) models. You can see more at his personal webpage.

Johan Edholm – Research Assistant


Johan is Polar Glider’s Research Assistant, managing among other things operational logistics, working conditions of the research assets, and general group coordination. He has previously completed both a B.Sc and a double M.Sc. under the supervision of Sebastiaan, Marcel, and Sarah Nicholson looking to quantify the role atmospheric rivers on the surface buoyancy in the Southern Ocean. In 2019 he joined the SCALE Spring Cruise to the Southern Ocean, deploying buoyancy gliders, Wave Gliders, buoys, both in water and on the ice! He spent his childhood in the archipelago just south of Gothenburg, fishing, tinkering with boat engines, and solving everyday problems around the house. This has led to an intense curiosity for the ocean, what makes it work, and an interest in building things, from decks and stairs, to concrete roads, or small boats from scraps. 


Martin Mohrmann – PhD student


Martin is a PhD student under the supervision of Seb Swart, Céline Heuzé and Helle Ploug. His main interests are upwelling processes in the ocean. Currently, he is researching the physical and biogeochemical processes and responses in the Weddell Sea Polynya.

He discovered his passion for geosciences with his Bachelor thesis about LIDAR measurements in the upper atmosphere. Specialising in oceanography and climate physics in his master studies at the University of Rostock, Martins master thesis is about the analytical modeling of upwelling systems and the response of the ecosystem. In his free time, he is either conquering the Swedish archipelago by kayak, or tinkering around with some software projects.

Isabelle Giddy – PhD student


Isabelle is an explorer of the natural world, with an unquenchable thirst for learning – from earth system science to anthropology. She has worked in education and marine conservation, speaks five languages, and is a co-founder of LIMPET South Africa, a rocky shore youth citizen science program. Isabelle is currently doing a PhD, under the supervision of Sebastiaan Swart at the University of Gothenberg, Sweden and the co-supervision of Sarah Nicholson and Isabelle Ansorge at the CSIR and the University of Cape Town, respectively. Her work is focused on understanding submesoscale processes in the Marginal Ice Zone of the Southern Ocean.


Hanna Rosenthal – PhD student


Hanna is doing a PhD to investigate surface heat fluxes over the Southern Ocean and its role in climate. She is supervised by Louise Biddle, Sebastiaan Swart and Marcel du Plessis. Her current research is closely linked to the Southern Ocean Carbon and Heat Impact on Climate (SO-CHIC) project. Observations from autonomous research platforms, such as Saildrone, and reanalysis data products, will be used to identify key scales and regions of heat flux variability. Hanna is currently working on Saildrone data from the first autonomous Antarctic Circumnavigation to understand how the various sizes (width) of oceanic fronts impact the heat exchange between the ocean and the atmosphere.

Theo Spira – PhD student

Theo is a PhD student under the supervision of Seb Swart and Marcel du Plessis. He is passionate about climate change, having graduated from the University of Exeter with a Master of Mathematics where he studied geophysical (and some astrophysical) fluid dynamics (thesis on overturning ocean circulation and Stommel’s box model under Prof. Geoffrey Vallis). 

Theo is investigating ocean ventilation across the Southern Ocean by considering how submesoscale processes in the mixed layer can enhance the possibility of transient ventilation events, which may result in changes to heat and carbon fluxes between the atmosphere and ocean. He is particularly interested in whether the seasonality of submesoscale activity causes an increase in likelihood of transient ventilation events or, in other words, an increase in ventilation potential. 


Estel Font – PhD student


Estel’s PhD study is opening up a new and different study region within the group –  investigating the processes governing the air-sea fluxes and submesoscale dynamics in the Gulf of Oman (Arabian Sea) using field missions by SeaExplorer gliders equipped with an ADCP. She is interested in relating these submesocale eddies, filaments and currents to the transport of oxygen to the most intense oxygen minimum zone worldwide found in the Arabian Sea. She is supervised by Bastien Queste and Sebastiaan Swart at the University of Gothenburg. Her bachelors is in Physics at Universitat Autonoma de Barcelona (Spain) and a MSc in Physical Oceanography at Göteborgs Universitet (Sweden) which she recently published


Stina Walhgren – Masters 2021-ongoing

Stina uses SWIFT buoys (ice-wave interactions buoys from Jim Thomson at APL) to study interactions between surface waves and sea ice in the Antarctic MIZ, with the main focus on attenuation of surface waves due to sea ice. These SWIFT buoys have been collecting data during austral winter and spring in the Weddell Sea MIZ in 2018-2019. 

Gianlucca Gerich – Masters 2021-ongoing

Gianlucca uses thermosalinograph data from cruises crossing the Drake passage to study the surface variability of submesoscale fronts, focusing on the distribution of surface gradients around the geostrophic frontal regions (ACC). The data has been obtained from SOCAT and is being studied in relation to the sea surface height distribution.

Johan Edholm – Masters 2019-2020 (with distinction)

Johan uses Seaglider and Wave Glider data to assess the impact of rainfall on upper ocean hydrography and circulation. He focuses on how large scale atmospheric rivers, transporting atmospheric moisture from as far as the Amazon rainforest, leads to large precipitation events over the Southern Ocean.

David Hagman – Masters 2020-2021 (with distinction)

Icebreakers collecting meteorology and radiation data are being used by David to calculate bulk air-sea heat fluxes over the Southern Ocean. He will estimate the time-space scale at which they vary as well as assess how the heat fluxes vary over different regions (ACC, MIZ, subtropics).


Most recent graduands
Yongqing Cai – PhD Visiting Fellow (China) 2021-2022 – MITgcm Submesoscale analysis in the S Ocean MIZ

Hanna Joy-Warren – Fullbright Scholar 2021-2022 – Saildrone Antarctic Circumnavigation Chl-a variability

Estel Font – Masters 2020-2021 (with distinction)  – Gulf of Oman mixed layer variability from glider data. 

Armand Ledanois – Masters 2020-2021 – EUREC4A/ATOMIC Saildrone data analysis with S Speich

Kevin Thielen – PhD student / Fullbright Scholar 2018-2019 – 1D PWP model mixing in the S Ocean

Johan Edholm – Bachelors 2019 (with distinction) – Atmospheric rivers in the S Ocean as detected using Wave Gliders

Hanna Rosethal – Masters 2019-2020 (with distinction) – Submesoscale fronts and air-sea heat fluxes from Saildrone data

Sun Jing – Bachelor 2019 (with distinction) – Reanalysis SST versus glider surface temperature comparisons with M. Krug

Jethan D’Hotman – Masters 2017-2019 – Gliders in the Agulhas Current with M Krug  

Chloe Blythe – Masters 2019 (with distinction) – Seal tag data and PWP model mixed layers


Isabelle Ansorge, University of Cape Town, South Africa

Alex Brearly, British Antarctic Survey, UK

Karen Heywood, UEA, UK

Celine Hueze, University of Gothenburg, Sweden

Marjolaine Krug, CSIR, South Africa

Craig Lee, University of Washington, USA

Amala Mahadevan, WHOI-MIT, USA

Mike Meredith, British Antarctic Survey, UK

Pedro Monteiro, CSIR, South Africa

Sarah Nicholson, CSIR, South Africa

Sabrina Speich, Ecole Normal, France

Laura de Steur, Norwegian Polar Institute, Norway

Sandy Thomalla, CSIR, South Africa

Andrew F. Thompson, CalTech, USA

Jim Thomson, University of Washington, USA

Anna Wahlin, University of Gothenburg, Sweden

%d bloggers like this: