Researcher Spotlight - Meet Dr. Hugo Lévy, Enhancing Climate Models

With a background rooted in fundamental physics and applied mathematics, Dr. Hugo Lévy has transitioned into climate science to contribute to pressing societal challenges through improved climate models His research aims to improve the representation of ocean dynamics in numerical models, with the broader goal of producing more reliable projections of future ocean conditions and climate impacts.In particular, he investigates how to optimally adjust the parameterization schemes used to represent subgrid-scale processes (typically at horizontal scales below 10km) in models, and how to accurately map the ocean floor topography in regions with rugged underwater landscapes, such as steep slopes around Antarctica.

What motivates you to work in this field?

“After completing my PhD degree in gravitational physics, during which I explored so-called modified gravity theories through numerical simulations, I felt the need to move towards more down-to-earth research topics. With this in mind, I turned to climate science, as I believe it has a more direct link to pressing societal concerns. Contributing my modest share to the improvement of climate models is partly what fuels my motivation as a scientist overall. Besides, changing fields of study is an incredible opportunity to gain new knowledge and skills, which is a strong personal development motivation for me.”

How has your background shaped your approach to climate science?

“Before embarking on this postdoctoral position, my studies, both at Master’s and PhD level, mainly lay at the crossroads between fundamental physics and applied mathematics. In exploring theories of gravity beyond general relativity, I realized how essential it is to be able to place trust in the results of numerical simulations. Questions such as: Is the problem that I am trying to solve well-posed? How can I assess, in an objective way, the accuracy of my numerical solution? were definitely issues that I felt very strongly about. For these reasons, the overarching goals and approaches of the TRR181 immediately resonated with me when I first read about the project! Relying on mathematics to try and enforce such fundamental physical principles as the conservation of the total energy of an isolated system in a numerical model is something that speaks to me.”

What are your primary research interests?

“In plain words, my research focuses on improving how ocean circulation is represented in climate-scale numerical models. Since the latter usually operate on grids too coarse to fully resolve small-scale processes, like mesoscale eddies, their effects have to be parametrized. I use optimization methods based on adjoint modelling to tune these so-called parametrization schemes by systematically matching coarse-resolution simulations to high-resolution benchmark models in realistic Antarctic shelf and slope regions. In this framework, not only tuning parameters, but also aspects of the model geometry, such as how bottom topography is represented, are treated as controls. Ultimately, the goal is then to translate these results into practical guidance for how modellers should choose and configure these degrees of freedom in other regional and global ocean modelling applications.”

What are the most pressing challenges in climate science, and how does your work contribute?

“Very schematically speaking, I would say that over the past decades, climate science has progressively shifted its emphasis from the question (1)’Is the climate warming?’ to (2) ‘Are we, humans, the cause?’ and, most recently, to (3) ‘What projections, impacts, adaptation and risk management are relevant?’ In this regard, I think the most valuable role of climate science now is to improve our ability to anticipate future conditions and support adaptation. This is precisely why, in my opinion, improving numerical climate models remains crucial today.

I have probably not been in the field long enough to claim a comprehensive view of all the most urgent challenges, but I see my work as contributing to the third point above. Namely, by improving how key physical processes are represented in numerical models, my research supports more reliable projections of future ocean conditions, and, in turn, better-informed impact assessments and adaptation planning.”

How does interdisciplinary collaboration enhance your research?

“I think human interactions are highly valuable for conducting good science, but from my experience, it is not always obvious how to create the conditions for productive scientific discussions. In that sense, a collaborative project such as the TRR181 is really on point, as it brings together researchers with sufficiently close research interests while maintaining a diversity of backgrounds and perspectives. This framework allows me to maintain a good grasp of the big picture, while also being able to delve into the details of my own projects with researchers whose expertise and interests are more closely aligned with mine.”

Any advice for young researchers?

“I would perhaps give an advice from my own career path, namely that it is never too late for one to make the shift to climate science. ;-)"
 

What is the best way to connect with you for potential research collaboration?

“One can reach out to me via my institutional email address: hugo.levy[at]awi.de. “