Physical oceanographer with a strong interest in satellite altimetry and research affinities at the intersection of oceanography, geophysics, geodesy, and instrumentation.
Yann-Treden Tranchant is a Research Associate with the Australian Antarctic Program Partnership at the Institute for Marine and Antarctic Studies at the University of Tasmania, Hobart. Yann-Tredent concluded a PhD in coastal oceanography and altimetry at La Rochelle University with the LIENSs laboratory and a Masters’ Degree in Physical Oceanography at Brest University/IUEM.
SWOT AdAC: What is your field of research and how did you choose it?
Yann-Treden Tranchant: I am a physical oceanographer with a strong interest in satellite altimetry. During my PhD, I enjoyed playing with marine drone acquisition and hydrodynamic models to improve our understanding of altimetry measurements in coastal regions and enhance their exploitation, in the perspective of the launch of SWOT satellite. I have developed research affinities at the intersection of oceanography, geophysics, geodesy, and instrumentation, that I am now applying in climate-related research in the Southern Ocean with my current position of Research Associate as part of the Australian Antarctic Program Partnership. Here, I take part in the SWOT-ACC SMST (aka FOCUS = Fine-scale Observations of Currents Under SWOT) campaign.
SWOT AdAC: How is your field of research related to SWOT?
YTT: My actual research is ‘focused’ on the influence of small-scale motions on large-scale ocean dynamics and poleward heat transport, particularly in an energetic meander of the Antarctic Circumpolar Current (ACC). With SWOT, we have a new (and amazing) view of the surface signature of fine-scale ocean dynamics, like filaments and small eddies, that are the ‘dirt under the carpet’ of present climate models, but impact greatly the heat transport across the Southern Ocean towards Antarctica. My interest is to assess how useful these SWOT observations are, when integrated with ancillary observing systems, satellite altimetry data, and ocean model outputs to quantify heat and carbon uptake and transfers in the Southern Ocean.
SWOT AdAC: What do you find exciting about SWOT and the SWOT-AdAC campaign in which you participated? How did you contribute to the campaign?
YTT: I’m feeling lucky, being an early-career researcher during a period of major technological and scientific advances in the field of satellite altimetry. In November-December 2023, I participated in the ambitious and intensive oceanographic FOCUS voyage on Australian CSIRO research vessel RV Investigator (part of the SWOT-AdAC campaign). Having starting my new position during the last months of preparation of the voyage, I have jumped into the deep end by being involved in the planning for the deployment of (semi-) lagrangian instruments, including drifters, EM-APEX, BGC-Argo (Argo float with biochemical sampling capabilities) and gliders. During the voyage, I was part of the team sampling the CTD rosette (a total of 111 CTD casts in one five-week voyage, what a baptism of fire !!). After (and before) years of processing remote-sensing and in-situ data, it is very exciting to ‘feel the physics’ of the ocean in a high-energy zone of the Antarctic Circumpolar Current. Experiencing how oceanographic data is collected will greatly help my understanding of in-situ data acquisition, their limitations and to realise their human-work (and financial) value. It is wonderful (and maybe indispensable) to have this and such memories in mind when one knows that the other part of the story also includes billions of hours sitting in front of a computer, struggling with coding or modeling frameworks.
SWOT AdAC: What are your plans after the SWOT-AdAC campaign (max 300 words)
YTT: A dollop of data processing, a sprinkle of scientific discussions, a dash of writing, and another voyage, I hope! We collected a comprehensive dataset in a very energetic meander of the ACC, that includes acquisition from a tall mooring, hundreds of CTD casts, Triaxus tows, shipborne underway sensors, gliders, profile floats and surface buoys, etc., all concurrently with SWOT observation: enough to fill the days of many researchers for a while!
I am with the Australian Antarctic Program Partnership as a Research Associate until 2026. In my new-found relationship with the Southern Ocean, I am discovering different types of physics, surrounded by brilliant researchers and technicians, and impressive technology. Against a background of dramatic change and exposed to constant data flow, I really feel that the new SWOT era will be cooperative and multi-disciplinary, thus I am also keen to start collaborative works with bio-geochemistry researchers as part of my position. By helping to fill some gaps in the complex story of the role of the Southern Ocean in the global climate system, I’ll try to make meaningful contributions to climate-related research into poleward heat transport to Antarctic ice shelves.
