205 citations · 407 across the 21 of their papers we have counts for
22 papers
Intermittency-induced transitions in fast-slow dynamical systems
Alessandro Barone, Alberto Carrassi, Jonathan Demaeyer +1
Intermittent dynamics are ubiquitous in the Earth system and often arise from the interaction of processes evolving on different time scales. In this work, we investigate how inter…
Emergence of Chaos in the Tropical Atmosphere: Study of the Weak Temperature Gradient System
Stéphane Vannitsem, Jonathan Demaeyer
The atmospheric tropical belt is believed to be more predictable than the extratropics. This question is revisited here by exploring the emergence of chaos in reduced-order model v…
Revisiting the Dynamical Properties of Pedlosky's Two-Layer Model for Finite Amplitude Baroclinic Waves
Nicolas De Ro, Jonathan Demaeyer, Stéphane Vannitsem
Baroclinic instability is a fundamental mechanism driving atmospheric dynamics. In this work, we revisit Pedlosky's two-layer model for finite amplitude baroclinic waves - a semina…
Structural Origins and Real-Time Drivers of Intermittency
Alessandro Barone, Alberto Carrassi, Thomas Savary +2
In general terms, intermittency is the property for which time evolving systems alternate among two or more different regimes. Predicting the instance when the regime switch will o…
Using Unstable Periodic Orbits to Understand Blocking Behaviour in a Low Order Land-Atmosphere Model
Oisín Hamilton, Jonathan Demaeyer, Michel Crucifix +1
Unstable Periodic Orbits (UPOs) were used to identify regimes, and transitions between regimes, in a reduced-order coupled atmosphere-land spectral model. In this paper we describe…
Self-attentive Transformer for Fast and Accurate Postprocessing of Temperature and Wind Speed Forecasts
Aaron Van Poecke, Tobias Sebastian Finn, Ruoke Meng +6
Current postprocessing techniques often require separate models for each lead time and disregard possible inter-ensemble relationships by either correcting each member separately o…
Variability and Predictability of a reduced-order land atmosphere coupled model
Anupama K Xavier, Jonathan Demaeyer, Stéphane Vannitsem
This study delves into the predictability of atmospheric blocking, zonal, and transition patterns utilizing a simplified coupled model. Initially, we comprehensively scrutinize the…
Extremes of summer Arctic sea ice reduction investigated with a rare event algorithm
Jerome Sauer, Jonathan Demaeyer, Giuseppe Zappa +2
Various studies identified possible drivers of extremes of Arctic sea ice reduction, such as observed in the summers of 2007 and 2012, including preconditioning, local feedback mec…
Multistability in a Coupled Ocean-Atmosphere Reduced Order Model: Non-linear Temperature Equations
Oisín Hamilton, Jonathan Demaeyer, Stéphane Vannitsem +1
Multistabilities were found in the ocean-atmosphere flow, in a reduced order ocean-atmosphere coupled model, when the non-linear temperature equations were solved numerically. In t…
Identifying efficient ensemble perturbations for initializing subseasonal-to-seasonal prediction
Jonathan Demaeyer, Stephen G. Penny, Stéphane Vannitsem
The prediction of the weather at subseasonal-to-seasonal (S2S) timescales is dependent on both initial and boundary conditions. An open question is how to best initialize a relativ…
Extratropical low-frequency variability with ENSO forcing: A reduced-order coupled model study
Stéphane Vannitsem, Jonathan Demaeyer, Michael Ghil
The impact of the El Niño-Southern Oscillation (ENSO) on the extratropics is investigated in an idealized, reduced-order model that has a tropical and an extratropical module. Unid…
Data assimilation for chaotic dynamics
Alberto Carrassi, Marc Bocquet, Jonathan Demaeyer +3
Chaos is ubiquitous in physical systems. The associated sensitivity to initial conditions is a significant obstacle in forecasting the weather and other geophysical fluid flows. Da…
Statistical Postprocessing for Weather Forecasts -- Review, Challenges and Avenues in a Big Data World
Stéphane Vannitsem, John Bjørnar Bremnes, Jonathan Demaeyer +21
Statistical postprocessing techniques are nowadays key components of the forecasting suites in many National Meteorological Services (NMS), with for most of them, the objective of…
Correcting for Model Changes in Statistical Postprocessing -- An approach based on Response Theory
Jonathan Demaeyer, Stéphane Vannitsem
For most statistical postprocessing schemes used to correct weather forecasts, changes to the forecast model induce a considerable reforecasting effort. We present a new approach b…
Comparison of stochastic parameterizations in the framework of a coupled ocean-atmosphere model
Jonathan Demaeyer, Stéphane Vannitsem
A new framework is proposed for the evaluation of stochastic subgrid-scale parameterizations in the context of MAOOAM, a coupled ocean-atmosphere model of intermediate complexity.…
Exploring the Lyapunov instability properties of high-dimensional atmospheric and climate models
Lesley De Cruz, Sebastian Schubert, Jonathan Demaeyer +2
The stability properties of intermediate-order climate models are investigated by computing their Lyapunov exponents (LEs). The two models considered are PUMA (Portable University…
Stochastic parameterization of subgrid-scale processes: A review of recent physically-based approaches
Jonathan Demaeyer, Stéphane Vannitsem
We review some recent methods of subgrid-scale parameterization used in the context of climate modeling. These methods are developed to take into account (subgrid) processes playin…
Stochastic parameterization of subgrid-scale processes in coupled ocean-atmosphere systems: Benefits and limitations of response theory
Jonathan Demaeyer, Stéphane Vannitsem
A stochastic subgrid-scale parameterization based on the Ruelle's response theory and proposed in Wouters and Lucarini [2012] is tested in the context of a low-order coupled ocean-…
The Modular Arbitrary-Order Ocean-Atmosphere Model: MAOOAM v1.0
Lesley De Cruz, Jonathan Demaeyer, Stéphane Vannitsem
This paper describes a reduced-order quasi-geostrophic coupled ocean-atmosphere model that allows for an arbitrary number of atmospheric and oceanic modes to be retained in the spe…
Low-frequency variability and heat transport in a low-order nonlinear coupled ocean-atmosphere model
Stéphane Vannitsem, Jonathan Demaeyer, Lesley De Cruz +1
We formulate and study a low-order nonlinear coupled ocean-atmosphere model with an emphasis on the impact of radiative and heat fluxes and of the frictional coupling between the t…
Trace formula for activated escape in noisy maps
J. Demaeyer, P. Gaspard
Using path-integral methods, a formula is deduced for the noise-induced escape rate from an attracting fixed point across an unstable fixed point in one-dimensional maps. The calcu…
Noise-induced escape from bifurcating attractors: Symplectic approach in the weak-noise limit
Jonathan Demaeyer, Pierre Gaspard
The effect of noise is studied in one-dimensional maps undergoing transcritical, tangent, and pitchfork bifurcations. The attractors of the noiseless map become metastable states i…