The Mathematics of Climate and the Environment

IHP, Paris, September 9 - December 21 2019



Deadline for financial support: March 15th, 2019

Registration is free however mandatory: http://www.ihp.fr/en/CEB/T3-2019

Course III Schedule

Course II: Big data, data assimilation, and uncertainty quantification

28 Oct.–8 Nov. 2019

The course will take place in the amphitheater of the Institut Henry Poincaré
11 Rue Pierre et Marie Curie, 75005 Paris, France


(a) Data assimilation & climate science applications 

           M. Bocquet (ENPC) & D. Crisan (Imperial College London)


(b) Big data & uncertainty quantification

            Omar Ghattas (U. Texas, Austin)


Schedule




Marc Bocquet 


Monday, October 28, 10:30-12:30

Lecture 1. Elementary principles of geophysical data assimilation. The Bayesian standpoint. Classical methods of data assimilation: 3D-Var, the Kalman filter, 4D-Var.


Tuesday, October 29, 10:30-12:30

Lecture 2. The ensemble Kalman filter and its variants: mathematical and algorithmic aspects.

Thursday, October 31, 10:30-12:30

Lecture 3. Recent advances —hybrid and ensemble variational techniques. What should one expect from machine learning and deep learning.


Dan Crisan


Tuesday, November 5, 10:30am-12:30pm

Lecture 1. Data assimilation as a stochastic filtering problem. Framework. The signal and the observation process. Prior/Posterior distribution. The linear/Kalman filter.


Wednesday, November 6, 10:30am-12:30pm

Lecture 2. Solving data assimilation problems using particle filters. Mathematical and methodological considerations. The standard particle filter. Model reduction. Tempering. Jittering. Nudging.

Thursday, November 7, 10:30am-12:30pm

Lecture 3. Two case studies: 2D Euler and 2D Two-layer quasigeostrophic model. Algorithmic considerations: Choice of initial condition, number of particles, assimilation step, reduction parameter. Forecast reliability.  


Omar Ghattas


Tuesday, November 5, 3-5pm

Lecture 1. Ill-posedness of inverse problems: Model problems, Tikhonov regularization, Morozov discrepancy, Bayesian formulation


Wednesday, November 6, 3-5pm

Lecture 2. The MAP estimate: large-scale optimization via inexact Newton-CG, adjoint-based gradients and Hessians via the Lagrangian formalism

Thursday, November 7, 3-5pm

Lecture 3. Laplace approximation of the posterior: Randomized eigensolvers, low-rank Hessian approximation, alternatives for highly data-informed problems

Friday, November 8, 10:30am-12:30pm 

Lecture 4. Large-scale Bayesian inverse problem case study: Inference

of basal friction in flow of the Antarctic ice sheet from InSAR satellite data 


Friday, November 8, 3-5pm 

Lecture 5. Markov chain Monte Carlo: Metropolis-Hastings, preconditioned Crank-Nicolson and generalized pCN for infinite-dimensional posteriors