Ocean Dynamics

, Volume 67, Issue 8, pp 1067–1094

Assessing an ensemble Kalman filter inference of Manning’s n coefficient of an idealized tidal inlet against a polynomial chaos-based MCMC

  • Adil Siripatana
  • Talea Mayo
  • Ihab Sraj
  • Omar Knio
  • Clint Dawson
  • Olivier Le Maitre
  • Ibrahim Hoteit
Article
Part of the following topical collections:
  1. Topical Collection on the 18th Joint Numerical Sea Modelling Group Conference, Oslo, Norway, 10-12 May 2016

Abstract

Bayesian estimation/inversion is commonly used to quantify and reduce modeling uncertainties in coastal ocean model, especially in the framework of parameter estimation. Based on Bayes rule, the posterior probability distribution function (pdf) of the estimated quantities is obtained conditioned on available data. It can be computed either directly, using a Markov chain Monte Carlo (MCMC) approach, or by sequentially processing the data following a data assimilation approach, which is heavily exploited in large dimensional state estimation problems. The advantage of data assimilation schemes over MCMC-type methods arises from the ability to algorithmically accommodate a large number of uncertain quantities without significant increase in the computational requirements. However, only approximate estimates are generally obtained by this approach due to the restricted Gaussian prior and noise assumptions that are generally imposed in these methods. This contribution aims at evaluating the effectiveness of utilizing an ensemble Kalman-based data assimilation method for parameter estimation of a coastal ocean model against an MCMC polynomial chaos (PC)-based scheme. We focus on quantifying the uncertainties of a coastal ocean ADvanced CIRCulation (ADCIRC) model with respect to the Manning’s n coefficients. Based on a realistic framework of observation system simulation experiments (OSSEs), we apply an ensemble Kalman filter and the MCMC method employing a surrogate of ADCIRC constructed by a non-intrusive PC expansion for evaluating the likelihood, and test both approaches under identical scenarios. We study the sensitivity of the estimated posteriors with respect to the parameters of the inference methods, including ensemble size, inflation factor, and PC order. A full analysis of both methods, in the context of coastal ocean model, suggests that an ensemble Kalman filter with appropriate ensemble size and well-tuned inflation provides reliable mean estimates and uncertainties of Manning’s n coefficients compared to the full posterior distributions inferred by MCMC.

Keywords

Coastal ocean model Manning’s n coefficients Parameter estimation Ensemble Kalman filter Polynomial chaos MCMC 

Copyright information

© Springer-Verlag Berlin Heidelberg 2017

Authors and Affiliations

  • Adil Siripatana
    • 1
  • Talea Mayo
    • 2
  • Ihab Sraj
    • 1
  • Omar Knio
    • 1
  • Clint Dawson
    • 3
  • Olivier Le Maitre
    • 4
  • Ibrahim Hoteit
    • 1
  1. 1.King Abdullah University of Science and TechnologyThuwalSaudi Arabia
  2. 2.Princeton UniversityPrincetonUSA
  3. 3.University of Texas at AustinAustinUSA
  4. 4.Laboratoire d’Informatique pour la Mecanique et les Sciences de l’IngénieurParisFrance

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