S.A.M. (Sacha) Sinet MSc

PhD Candidate
Physical Oceanography

My current research focuses on how climatic subsystems interact through cascading processes, especially when subject to stochastic noise and nonautonomous effects. A better understanding of such behaviours could, among other things, indicate early signs of future climatic bifurcations.

The interacting ocean circulation and polar ice sheets

I study the interacting Atlantic Meridional Overturning Circulation (AMOC), Greenland ice sheet and West Antarctica ice sheet, the most prominent example of climate components that are prone to cascading tipping events (see Figure). These are fundamental for the functioning of the present-day climate, and form a complex coupled system in which some interactions are poorly understood. In particular, I study mechanisms behind a possible stabilization of the AMOC originating from a collapse of the West Antarctica ice sheet.   

Simplified representation of the interacting system including the AMOC, Greenland ice sheet and West Antarctica ice sheet.  The tipping of some components may have stabilizing or destabilizing impact on some others (green and red arrows, respectively), but some of the impacts remain unclear (grey arrow).

Coupled dynamical systems

I study the complexity that arises from the coupling of two (or more) systems that are individually prone to tipping. On one hand, I am interested in how the bifurcation structure of such coupled systems can be understood from the intrinsic bifurcation structure of each individual component. On the other hand, I investigate how safe overshoot events may be observed as the tipping of a leading system destabilizes a following system, depending on the nature of the interaction and the involved timescales. 

This project is part of the EU-funded H2020 Innovative Training Network (ITN) "Multiscales and Critical Transitions in the Earth System" (CriticalEarth),