2021,
N. Perez, P. Delplace, A.
Venaille. Unidirectional modes
induced by nontraditional Coriolis force in
stratified fluids
Submitted .pdf
New trapped modes
supported by compressible rotating stratified
flows are found using tools from topology. This
shows a striking manifestion of nontraditional
Coriolis effects that are often neglected in
geophysical context.

2021,
A. Venaille, P. Delplace. Wave topology brought to
the coast Physical Review Research .pdf
Coastal Kelvin waves were
arguably the first unidirectional trapped modes
found in a physical system. We show the
topological origin of these modes, by highlighting
the central role of bottom topography variations.

2021,
N. Perez , P. Delplace, A. Venaille. Manifestation of Berry
curvature in geophysical ray tracing Proceedings
of the Royal Society A .pdf
Shows that Berry curvature
induces weak bending of shallow water wavepackets in
the presence of planetary vorticity gradients.
This leads to a systematic drift in equatorial ray
tracing, an effect analogous to anomalous Hall
effect.

2020,
P. Delplace, A. Venaille. From
the geometry of Foucault's pendulum to topological
planetary waves Comptes Rendus Physique (CRAS) .pdf
Featured
in Nature
Physics by M. Buchanan
Short review on
topological waves in astrophysical and geophysical
flows, with emphasis on the consequences of planet
rotation and sphericity that can be understood
with geometrical tools such as the Berry phase and
the Berry curvature.

2020,
A. Renaud, A. Venaille. On
HoltonLindzenPlumb model for mean flow reversals
in stratified fluids
Quaterly Journal of the Royal Meteorological
Society .pdf
Starting from Boussinesq
equations, we discuss the existence of a
distinguished limit for the derivation of a
celebrated 1D idealized model for Quasibiennial
oscillations of equatorial winds. 
2020, A. Venaille.
Quasigeostrophy
against the wall Journal of
Fluid Mechanics  Rapids .pdf
Coasts are obstructions to
the classical derivation of stratified
quasigeostrophic equations, due to the
propagation of Kelvin waves trapped along the
boundary. Revisits a coupled model proposed by
DerembleJohnsonDewar to describe cyclone
formation by Kelvin wave shocks.

2020, C. Tauber, P.
Delplace, A. Venaille. Anomalous
bulkedge correspondence in continuous media  Physical
Review Research,
.pdf
Editors'
suggestion
Shows that the number of
chiral edge states filling a frequency gap is
generally not topologically protected in
continuous systems with a sharp boundary, but that
a bulkedge correspondence
is recovered when ghost modes hidden in the
asymptotic part of the spectrum are taken into
account.

2019, C. Tauber, P.
Delplace, A. Venaille. A
bulkinterface correspondence for equatorial waves  Journal of
Fluid Mechanics  Rapids
.pdf
Shows that a topological
index can be assigned to a given hemisphere for
shallow water flows in the presence of odd viscous
terms, and discusses consequences for equatorial
waves. 
2019, M. Perrot, P.
Delplace, A. Venaille. Topological
transition in stratified fluids  Nature
Physics .pdf featured
as News
and Views by T. Dowling
Relates the existence of atmospheric Lamb waves to peculiar topological
properties carried by acoustic and internal
gravity waves when mirror symmetry in vertical
direction is broken by gravity and density
stratification. 
2019,
P. Delplace,
A. Venaille. De la topologie dans les
ondes équatorialesLa Gazette des
Mathématiques .pdf
Review on topological
waves in geophysical fluid dynamics, making a
connection with the longstanding problem of tides (in french).

2019, A. Renaud, L.P.
Nadeau, A. Venaille. Periodicity
disruption of a model quasibiennial oscillation
of equatorial winds  Physical
Review Letter .pdf
, featured in Physics
Shows the existence of a
quasiperiodic route to chaos in idealized models
of equatorial atmospheres, and investigates the
response to external perturbations, motivated by
an odd recent evolution of the QBO.

2018, A. Renaud, A.
Venaille. Boundary
streaming by internal waves  Journal of
Fluid Mechanics .pdf
Investigates meanflow
generation by damped internal gravity waves close
to an undulating boundary. 
2018, T. Dauxois, S.
Joubaud, P. Odier, A. Venaille. Instabilities
of
internal wave beams  Annual
Review of Fluid Mechanics 2018
.pdf
Reviews the peculiar
effects of nonlinearities on internal wave beams,
including streaming and triadic resonant
instability. 
2017, P. Delplace, J.B.
Marston, A. Venaille. Topological
origin
of equatorial waves  Science .pdf
featured in Physicsworld
by P. Bal, communiqué
CNRS
Shallow water waves present
topological singularities
as a consequence of Earth rotation breaking
timereversal symmetry. This can be related to the
emergence of two unidirectional trapped modes
along the equator, the celebrated Kelvin and Yanai
waves. 
2017, Y. Yasuda, F.
Bouchet, A. Venaille. A new
Interpretation of vortexsplit stratospheric
sudden warmings in terms of equilibrium
statistical mechanics  Journal of
the Atmospheric Science .pdf
Spontaneous splitting of
the polar vortex as an abrupt transition from a
quasistationary cyclonic state to an anticyclonic
equilibrium state when an effective topography is
varied.

2016, A. Venaille, L.
Gostiaux, J. Sommeria. A
statistical mechanics approach to mixing in
stratified fluids  Journal of
Fluid Mechanics .pdf
Uses statistical mechanics
to predict how much mixing occurs when a given
amount of energy is injected into a stratified
fluid.

2016, A. Renaud, A.
Venaille, F. Bouchet. Equilibrium
statistical mechanics and energy partition for
the shallow water model  Journal of
Statistical Physics
.pdf
Full computation of
statistical equilibrium states of the shallow
water model using large deviation theory. Predicts
the concommitant emergence of a large scale
vortical flow and energy loss towards small scales
on the form of inertiagravity
waves.

2015, A. Venaille, T.
Dauxois, S. Ruffo. Violent
relaxation in twodimensional flows with varying
interactions  Physical
Review E  Rapid Communication
.pdf
Shows that the range of
interaction between fluid particles plays a
crucial role in selecting the large scale flow
topology during the relaxation of an unstable
initial state towards equilibrium.

2014, A. Venaille,
L.P. Nadeau, G. K. Vallis. Ribbon
turbulence  Physics
of Fluids, .pdf
Research
Highlights
Ribbons are surface
intensified jets in the large bottom friction
limit of geostrophic turbulence. Their dynamics
results from a competition between baroclinic instability and
the relaxation toward an
equilibrium state.
Movies:
weak
friction
intermediate friction large
friction

2012, G. Bordes, A.
Venaille, S. Joubaud, P. Odier, T. Dauxois.
Experimental
observation of strong mean flows generated by
internal gravity waves  Physics of
Fluids .pdf
Shows that a monochromatic
wave beam propagating in a stratified viscous
fluid induces a robust and strong jet flowing
outward the wave generator. 
2012, A. Venaille.
Bottomtrapped
currents
as statistical equilibrium states above topography
anomalies  Journal of
Fluid Mechanics  Rapids .pdf
Shows that in presence of
a sufficiently large topographic bump, an initial
surfaceintensified random velocity field evolves
towards a bottomtrapped anticyclonic mean flow. 
2012, A. Venaille, G.
K. Vallis, S.M. Griffies. The
catalytic
role
of beta effect in barotropization processes  Journal of
Fluid Mechanics .pdf
Shows that the presence of
planetary vorticity gradients favors the tendency
to spread the energy on the vertical in stratified
quasigeostrophic turbulent flows, and that
statistical mechanics arguments account for this
phenomenon. 
2012, F. Bouchet, A.
Venaille. Statistical
mechanics
of twodimensional and geophysical flows  Physics
Reports .pdf
Review paper with
emphasis on RobertSommeriaMiller
equilibrium theory. Former statistical approaches
are also discussed, as well as current
developments in out of equilibrium context. 
2011, A.
Venaille, G.K. Vallis, K.S. Smith. Baroclinic
turbulence
in the ocean: analysis with primitive equation and
quasigeostrophic simulations  Journal of
Physical Oceanography .pdf
Tests the
hypothesis that oceanic eddies result from
local baroclinic instabilities, and examines the
factors determining their distribution, length
scale, magnitude and structure. 
2011, A. Venaille, J.
Le Sommer, J.M. Molines, B. Barnier. Stochastic
variability
of large scale oceanic flows above topography
anomalies  Geophysical
Research Letters .pdf ,
communiqué
CNRS
A stochastic mechanism is
proposed to interpret the dynamics of eddydriven
recirculations above closed contours of bottom
topography. This may account for the observed low
frequency variability of the Zapiola anticyclone. 
2011, A.
Venaille, F. Bouchet. Oceanic
rings
and jets as statistical equilibrium states  Journal of
Physical Oceanography .pdf
Using statistical
mechanics arguments, oceanic rings are
interpreted as "bubbles" of homogenized potential
vorticity. It may provide an explanation for their
ubiquity, their shape, and their drift. 
2011, A.
Venaille, F. Bouchet. Solvable
phase
diagrams and ensemble inequivalence for
twodimensional and geophysical turbulent flows
 Journal of
Statistical Physics .pdf
Companion paper of PRL09
below. Discusses symmetry breaking associated with
the generic occurrence of ensemble inequivalence,
and the surprising effect of the Rossby
radius of deformation (a screening length scale). 
2009, A.
Venaille, F. Bouchet. Statistical
Ensemble
Inequivalence and Bicritical Points for
TwoDimensional Flows and Geophysical Flows 
Physical
Review Letters .pdf
It is shown that
statistical ensemble inequivalence and negative
specific heat occur for a wide class of
models and parameters, including Fofonoff
flows, and are related to previously observed
phase transitions in the flow topology. 
2008, A.
Venaille, J. Sommeria. Is
mixing a selfconvolution process ? 
Physical
Review Letters .pdf
Experimental tests of the
selfconvolution model for mixing of a passive
tracer. It is shown that the model is doing
well at sufficiently late stage of
mixing. 
2007, A.
Venaille, J. Sommeria. A
dynamical equation for the distribution of a
scalar advected by turbulence.  Physics of Fluids
.pdf
Provides phenomenological
arguments showing that the mixing of a
passive tracer through turbulent cascades may be
represented as a succession of selfconvolutions
of the tracer distribution. 
2005, A.
Venaille, P. Varona, M.I. Rabinovich.
Synchronization
and coordination of sequences in two neural
ensembles  Physical Review E
.pdf
Synchronization properties
emerging from the coupling
of two chaotic systems are
investigated. This
illustrates how a mollusk can scan
randomly an area to find a prey, while keeping
some efficiency in swimming.
