Results 1 to 10 of about 1,061,321 (345)

The analog data assimilation [PDF]

Monthly Weather Review, 2017
In light of growing interest in data-driven methods for oceanic, atmospheric, and climate sciences, this work focuses on the field of data assimilation and presents the analog data assimilation (AnDA).
Ailliot, Pierre, Fablet, Ronan, Lguensat, Redouane, Pulido, Manuel Arturo, Tandeo, Pierre   +4 more
core   +6 more sources

Displacement Data Assimilation [PDF]

Journal of Computational Physics, 2016
We show that modifying a Bayesian data assimilation scheme by incorporating kinematically-consistent displacement corrections produces a scheme that is demonstrably better at estimating partially observed state vectors in a setting where feature ...
Mariano, Arthur J., Restrepo, Juan M., Rosenthal, W. Steven, Venkataramani, Shankar C.   +3 more
core   +3 more sources

Data assimilation in operator algebras. [PDF]

Proc Natl Acad Sci U S A, 2023
We develop an algebraic framework for sequential data assimilation of partially observed dynamical systems. In this framework, Bayesian data assimilation is embedded in a nonabelian operator algebra, which provides a representation of observables by multiplication operators and probability densities by density operators (quantum states).
Freeman D, Giannakis D, Mintz B, Ourmazd A, Slawinska J.   +4 more
europepmc   +4 more sources

Variational Data Assimilation via Sparse Regularization [PDF]

Tellus A, 66 (2014), no. 21789, 1-17, 2013
This paper studies the role of sparse regularization in a properly chosen basis for variational data assimilation (VDA) problems. Specifically, it focuses on data assimilation of noisy and down-sampled observations while the state variable of interest exhibits sparsity in the real or transformed domain.
Ebtehaj, A. M., Foufoula-Georgiou, E., Lerman, G., Zupanski, M.   +3 more
arxiv   +4 more sources

Evaluating Data Assimilation Algorithms [PDF]

Monthly Weather Review, 2012
Data assimilation leads naturally to a Bayesian formulation in which the posterior probability distribution of the system state, given the observations, plays a central conceptual role.
A. M. Stuart, Anderson, Apte, Apte, Apte, Arulampalam, Auvinen, Bain, Banks, Banks, Bengtsson, Bennett, Brett, Brooks, Bryson, Bröcker, Carrassi, Chorin, Chorin, Cotter, Cotter, Courtier, Cox, Cox, Doucet, Evensen, Evensen, Evensen, Fisher, Hamill, Harlim, Harvey, Hesthaven, Hinze, Jazwinski, K. J. H. Law, Kaipio, Kalman, Kalnay, Kelley, Lawless, Lei, Leutbecher, Liu, Lorenc, Lorenz, Lorenz, Majda, Meng, Miller, Nocedal, Palmer, Quinn, Saad, Snyder, Stuart, Talagrand, Tarantola, Temam, Tippett, Toth, Trefethen, van Leeuwen, van Leeuwen, Vogel, Vogel, Zhang, Zhang, Zupanski   +68 more
core   +8 more sources

Variational assimilation of Lagrangian data in oceanography [PDF]

PAMM, 2006
We consider the assimilation of Lagrangian data into a primitive equations circulation model of the ocean at basin scale. The Lagrangian data are positions of floats drifting at fixed depth.
Assenbaum M Reverdin G, De Mey P, Forget G, Ghil M, Ghil M, Ide K, Jazwinski A H, Le Dimet F X, Lions J L, Lions J L, Madec G, Maëlle Nodet, Ngodock H E, Penenko V V, Reynaud T, Salman H, Talagrand O, Temam R, Thacker W C   +18 more
core   +14 more sources

A Time-parallel Approach to Strong-constraint Four-dimensional Variational Data Assimilation [PDF]

, 2015
A parallel-in-time algorithm based on an augmented Lagrangian approach is proposed to solve four-dimensional variational (4D-Var) data assimilation problems. The assimilation window is divided into multiple sub-intervals that allows to parallelize cost function and gradient computations.
Rao, Vishwas, Sandu, Adrian
arxiv   +3 more sources

Data Assimilation: A Mathematical Introduction [PDF]

arXiv, 2015
These notes provide a systematic mathematical treatment of the subject of data assimilation.
Law, K. J. H., Stuart, A. M., Zygalakis, K. C.   +2 more
arxiv   +3 more sources

Stabilized nonconforming finite element methods for data assimilation in incompressible flows [PDF]

arXiv, 2016
We consider a stabilized nonconforming finite element method for data assimilation in incompressible flow subject to the Stokes' equations. The method uses a primal dual structure that allows for the inclusion of nonstandard data. Error estimates are obtained that are optimal compared to the conditional stability of the ill-posed data assimilation ...
Burman, Erik, Hansbo, Peter
arxiv   +5 more sources

Data Assimilation by Artificial Neural Networks for an Atmospheric General Circulation Model: Conventional Observation [PDF]

arXiv, 2014
This paper presents an approach for employing artificial neural networks (NN) to emulate an ensemble Kalman filter (EnKF) as a method of data assimilation. The assimilation methods are tested in the Simplified Parameterizations PrimitivE-Equation Dynamics (SPEEDY) model, an atmospheric general circulation model (AGCM), using synthetic observational ...
Cintra, Rosangela S., Velho, Haroldo F. de Campos   +1 more
arxiv   +3 more sources