Anelastic sensitivity kernels with parsimonious storage for adjoint tomography and full waveform inversion

D Komatitsch, Z **e, E Bozdağ… - Geophysical Journal …, 2016 - academic.oup.com
We introduce a technique to compute exact anelastic sensitivity kernels in the time domain
using parsimonious disk storage. The method is based on a reordering of the time loop of …

A data assimilation algorithm for the subcritical surface quasi-geostrophic equation

MS Jolly, VR Martinez, ES Titi - Advanced Nonlinear Studies, 2017 - degruyter.com
In this article, we prove that data assimilation by feedback nudging can be achieved for the
three-dimensional quasi-geostrophic equation in a simplified scenario using only large …

Data assimilation in 2D hyperbolic/parabolic systems using a stabilized explicit finite difference scheme run backward in time

AS Carasso - Applied Mathematics in Science and Engineering, 2024 - Taylor & Francis
An artificial example of a coupled system of three nonlinear partial differential equations
generalizing 2D thermoelastic vibrations, is used to demonstrate the effectiveness, as well …

Data assimilation experiments using diffusive back-and-forth nudging for the NEMO ocean model

GA Ruggiero, Y Ourmieres, E Cosme… - Nonlinear Processes …, 2015 - npg.copernicus.org
The diffusive back-and-forth nudging (DBFN) is an easy-to-implement iterative data
assimilation method based on the well-known nudging method. It consists of a sequence of …

Data assimilation finite element method for the linearized Navier–Stokes equations in the low Reynolds regime

M Boulakia, E Burman, MA Fernández… - Inverse …, 2020 - iopscience.iop.org
In this paper, we are interested in designing and analyzing a finite element data assimilation
method for laminar steady flow described by the linearized incompressible Navier–Stokes …

Computing ill-posed time-reversed 2D Navier–Stokes equations, using a stabilized explicit finite difference scheme marching backward in time

AS Carasso - Inverse problems in science and engineering, 2020 - Taylor & Francis
This paper constructs an unconditionally stable explicit finite difference scheme, marching
backward in time, that can solve an interesting but limited class of ill-posed, time-reversed …

Stable explicit stepwise marching scheme in ill-posed time-reversed 2D Burgers' equation

AS Carasso - Inverse problems in science and engineering, 2019 - Taylor & Francis
This paper constructs an unconditionally stable explicit difference scheme, marching
backward in time, that can solve a limited, but important class of time-reversed 2D Burgers' …

Stabilized leapfrog scheme run backward in time, and the explicit O(Δ t)2 stepwise computation of ill-posed time-reversed 2D Navier–Stokes equations

AS Carasso - Inverse Problems in Science and Engineering, 2021 - Taylor & Francis
Richardson's leapfrog scheme is notoriously unconditionally unstable in well-posed,
forward, linear dissipative evolution equations. Remarkably, that scheme can be stabilized …

Data assimilation in 2D viscous Burgers equation using a stabilized explicit finite difference scheme run backward in time

AS Carasso - Inverse Problems in Science and Engineering, 2021 - Taylor & Francis
The 2D viscous Burgers equation is a system of two nonlinear equations in two unknowns, u
(x, y, t), v (x, y, t). This paper considers the data assimilation problem of finding initial values …

Detectability and state estimation for linear age-structured population diffusion models

K Ramdani, M Tucsnak, J Valein - ESAIM: Mathematical Modelling …, 2016 - esaim-m2an.org
We investigate a state estimation problem for an infinite dimensional system appearing in
population dynamics. More precisely, given a linear model for age-structured populations …