Ocean Melancholia
Exploring the edge of multistable ocean currents
Hi, I'm Reyk!
I use maths and physics to better understand climate change.
My research interests lie at the intersection of complex systems, statistical physics and earth system science. As a postdoc at the Institute for Marine and Atmospheric Research Utrecht, I am studying the risk of climate tipping points, particularly concerning the Atlantic ocean circulation.
- since 2025: Postdoctoral researcher at Utrecht University, Netherlands
- 2021-2025: PhD candidate in Applied Mathematics, University of Reading, UK
- 2019-2021: M.Sc. in Physics, University of Copenhagen, Denmark
- 2015-2019: B.Sc. in Physics, Free University of Berlin, Germany
News
Comment
Balancing Earth science careers in an unequal world
What we can do about Global North-South inequalities.
11 Jan 2025
New publication
Saddle avoidance in multiscale systems
Click to read open-access in Physical Review Research.
2 Dec 2024
Call for papers
Focus Issue: Mathematics of Planet Earth
Theory, models, data - Submit your paper to Journal of Physics: Complexity by 31 May.
21 Nov 2024
Call for abstracts
The Climate Model Hierarchy
Join our session NP1.2 at EGU25! Submit by 15 January.
26 Oct 2024
Upcoming event
APS Climate Physics Tutorial
4 hours of climate theory at the APS Global Physics Summit, March 2025.
20 Oct 2024
Software release
CriticalTransitions.jl
v0.4.0 - Now using the brand new CoupledSDEs type of DynamicalSystems.jl.
Projects
Saddle avoidance
When noise kicks you where you wouldn't expect
Modeling diurnal warm layers
A more realistic sea surface for cloud modeling
Oscillator networks with delay
Stability conditions with application to power grids
Public science & outreach
Fairbrother Lecture 2024
I had the exciting opportunity to deliver the Fairbrother Lecture 2024 at the University of Reading, a public lecture given by a PhD student each year.
Breaking the walls of...
... climate predictability: Watch my 3-minute thesis pitch presented at the finals of the MSCA Falling Walls Lab 2022 competition.
Publications
Peer-reviewed
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Saddle avoidance of noise-induced transitions in multiscale systems
Reyk Börner, Ryan Deeley, Raphael Römer, Tobias Grafke, Valerio Lucarini & Ulrike Feudel
Physical Review Research 6, L042053 (2024) PDF -
Limits of predictability of the asymptotic state of the Atlantic Meridional Overturing Circulation in a conceptual climate model
Oliver Mehling, Reyk Börner & Valerio Lucarini
Physica D: Nonlinear Phenomena, 459, 134043 (2024) Link -
Delay master stability of inertial oscillator networks
Reyk Börner, Paul Schultz, Benjamin Ünzelmann, Deli Wang, Frank Hellmann & Jürgen Kurths
Physical Review Research 2, 023409 (2020) Link
Preprints
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Simulated millennial-scale climate variability driven by a convection-advection oscillator
Yvan Romé, Ruza Ivanovic, Lauren Gregoire, Didier Swingedouw, Sam Sherriff-Tadano & Reyk Börner
Preprint (2024) Link -
DiuSST: A conceptual model of the diurnal warm layer for idealized atmospheric simulations with interactive SST
Reyk Börner, Jan O. Haerter & Romain Fiévet
arXiv preprint arXiv:2205.07933 (2024) PDF
Theses
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Modeling diurnal sea surface warming in the tropical ocean
An interactive boundary condition for idealized atmospheric simulations
MSc thesis (2021) PDF -
Master stability of inertial oscillators with delay
An analytical approach applied to renewable power grids
BSc thesis (2019) PDF
Other works
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Balancing Earth science careers in an unequal world
Nadia Testani et al.
Communications Earth & Environment 6, 22 (2025) Link
See also on Google Scholar.
Software
CriticalTransitions.jl
A Julia package offering a toolbox for noise- and rate-induced transitions in dynamical systems. Based on DynamicalSystems.jl and DifferentialEquations.jl.
Edge tracking in Attractors.jl
Implementation of the edge tracking algorithm to find so-called edge states or Melancholia states (chaotic saddles) in multistable dynamical systems.
DiuSST - diurnal warm layer model
Python implementation of three models of diurnal sea surface warming: the DiuSST model, the Zeng-Beljaars model, and a simple slab ocean model.
See also on Github.