Oscillations and instabilities in the climate system

lphys2264  2021-2022  Louvain-la-Neuve

Oscillations and instabilities in the climate system
5 credits
30.0 h
Q2

This biannual learning unit is being organized in 2021-2022
Teacher(s)
Language
English
Prerequisites
Having followed the courses LPHYS2114, LPHYS2162 and LPHYS2163 is an asset.
Main themes
Elementary concepts of dynamical stability,  fundamental notions of geophysical fluid dynamics, linear waves in shallow-water, linear wave theory and applications (equatorial waves, sea-waves, tides), unstable waves, linear theory (Kelvin-Helmholtz, baroclinic and barotropic instability),  oscillation and relaxation phenomena in the ocean-atmosphere system across scales (annual to millennial) and their contribution to the spectrum of variability, critical phenomena.
Aims

At the end of this learning unit, the student is able to :

1 a.     Contribution of the teaching unit to the learning outcomes of the programme (PHYS2M and PHYS2M1)
  • 1.1, 1.2, 1.5
  • 2.3, 2.5
  • 3.1, 3.2, 3.3
  • 4.2
  • 5.1, 5.2, 5.3, 5.4
  • 6.1, 6.2, 6.3, 6.5
  • 7.1, 7.2, 7.3, 7.4, 7.5, 7.6
  • 8.1
b.    Specific learning outcomes of the teaching unit
At the end of this teaching unit, the student will be able to :
  1. Explain the principle of linear stability analysis;
  2. Derive the shallow-water model and explain its interest for atmospheric and ocean waves
  3. Apply the principle of linear stability analysis  to derive theories for atmospheric and oceanic waves (gravity waves, Rossby waves, Kelvin waves) and instabilities (baroclinic and barotropic instability)
  4. Explain the principle of a climatic oscillation in terms of dynamical systems theory
  5. Demonstrate the link between these theories and actual phenomena in the ocean-atmosphere system (El-Nino, Madden-Julien instability, Atlantic oscillations, abrupt desertification) and discuss their limitations and importance for our understanding of the ocean-atmosphere dynamics
  6. Analyse a specific phenomenon involving atmospheric and oceanic waves, instabilities, or oscillations on the basis of available literature and communicate this analysis to colleagues.
  7. Criticise the presentation and provide constructive feedback to colleagues on the scientific aspects of the presentation.
  8. Synthesise current concerns about oscillations and instabilities in the climate system
 
Content
  1. Motivation
    • the climate variability spectrum
    • basic concepts of dynamic stability
  2. Linear waves
    • shallow-water model
    • gravity waves, Poincare waves
    • two-layer model and effective gravity
    • equatorial waves
    • Kelvin coastal waves (and tides)
    • Rossy waves
  3. Hydrodynamical instability (linear theory)
    • general principle
    • Kelvin-Helmholtz instability
    • baroclinic and barotropic instability
  4. Oscillations and relaxation phenomena in the climate system
    • general background and principles
    • applications and conceptual models
  5. Critical Phenomena
    • modėle conceputels of climate instability
    • contemporary issues
  6. Case studies (to be presented by students)
Teaching methods
Lectures for the fundamentals (with syllabus)
Applications presented and prepared by the students according to the flipped classroom principle.
A portfolio of reference texts made available by the teacher
Evaluation methods
Feedback during the flipped classes.
Case studies : oral presentation and final report.
Bibliography
B. Cushman-Roisin et J. M. Beckers, Introduction to Geophysical Fluid Dynamics, Volume 101, Elsevier
H. Dijkstra, Nonlinear climate dynamics, Cambridge University Press
Faculty or entity


Programmes / formations proposant cette unité d'enseignement (UE)

Title of the programme
Sigle
Credits
Prerequisites
Aims
Master [120] in Geography : Climatology

Master [120] in Physics

Master [60] in Physics