An ensemble adjustment Kalman filter for data assimilation

JL Anderson - Monthly weather review, 2001 - journals.ametsoc.org
A theory for estimating the probability distribution of the state of a model given a set of
observations exists. This nonlinear filtering theory unifies the data assimilation and …

Model error representation in an operational ensemble Kalman filter

PL Houtekamer, HL Mitchell… - Monthly Weather …, 2009 - journals.ametsoc.org
Abstract Since 12 January 2005, an ensemble Kalman filter (EnKF) has been used
operationally at the Meteorological Service of Canada to provide the initial conditions for the …

[HTML][HTML] Constraining chaos: Enforcing dynamical invariants in the training of reservoir computers

JA Platt, SG Penny, TA Smith, TC Chen… - … Journal of Nonlinear …, 2023 - pubs.aip.org
Drawing on ergodic theory, we introduce a novel training method for machine learning
based forecasting methods for chaotic dynamical systems. The training enforces dynamical …

On the equivalence between Kalman smoothing and weak‐constraint four‐dimensional variational data assimilation

M Fisher, M Leutbecher, GA Kelly - Quarterly Journal of the …, 2005 - Wiley Online Library
The fixed‐interval Kalman smoother produces optimal estimates of the state of a system over
a time interval, given observations over the interval, together with a prior estimate of the state …

Comparison of local ensemble transform Kalman filter, 3DVAR, and 4DVAR in a quasigeostrophic model

SC Yang, M Corazza, A Carrassi… - Monthly weather …, 2009 - journals.ametsoc.org
Local ensemble transform Kalman filter (LETKF) data assimilation, three-dimensional
variational data assimilation (3DVAR), and four-dimensional variational data assimilation …

Treating strong adjoint sensitivities in tropical eddy‐permitting variational data assimilation

I Hoteit, B Cornuelle, A Köhl… - Quarterly Journal of the …, 2005 - Wiley Online Library
A variational data assimilation system has been implemented for the tropical Pacific Ocean
using an eddy‐permitting regional implementation of the MITgcm. The adjoint assimilation …

Constraining Chaos: Enforcing dynamical invariants in the training of recurrent neural networks

JA Platt, SG Penny, TA Smith, TC Chen… - arxiv preprint arxiv …, 2023 - arxiv.org
Drawing on ergodic theory, we introduce a novel training method for machine learning
based forecasting methods for chaotic dynamical systems. The training enforces dynamical …

Bred vectors of the Zebiak–Cane model and their potential application to ENSO predictions

M Cai, E Kalnay, Z Toth - Journal of Climate, 2003 - journals.ametsoc.org
The breeding method is used to obtain the bred vectors (BV) of the Zebiak–Cane (ZC)
atmosphere–ocean coupled model. Bred vectors represent a nonlinear, finite-time extension …

Comparing hybrid data assimilation methods on the Lorenz 1963 model with increasing non-linearity

M Goodliff, J Amezcua… - Tellus A: Dynamic …, 2015 - Taylor & Francis
We systematically compare the performance of ETKF-4DVAR, 4DVAR-BEN and 4DENVAR
with respect to two traditional methods (4DVAR and ETKF) and an ensemble transform …

Variational assimilation

O Talagrand - Data assimilation: making sense of observations, 2010 - Springer
The expression variational assimilation designates a class of assimilation algorithms in
which the fields to be estimated are explicitly determined as minimizers of a scalar function …