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The computation of Lagrangian coherent structures (LCS) has become a standard tool for the analysis of advective transport in unsteady flow applications. LCS identification is primarily accomplished by evaluating measures based on the…

Fluid Dynamics · Physics 2022-09-29 Siavash Ameli , Yogin Desai , Shawn C. Shadden

As most mathematically justifiable Lagrangian coherent structure detection methods rely on spatial derivatives, their applicability to sparse trajectory data has been limited. For experimental fluid dynamicists and natural scientists…

Fluid Dynamics · Physics 2024-11-20 Nikolas O. Aksamit , Alex P. Encinas-Bartos , George Haller , David E. Rival

Oceanic surface flows are dominated by finite-time Lagrangian coherent structures that separate regions of qualitatively different dynamical behavior. Among these, eddy boundaries are of particular interest. Their exact identification is…

Atmospheric and Oceanic Physics · Physics 2019-05-17 Benedict Lünsmann , Holger Kantz

We review and test twelve different approaches to the detection of finite-time coherent material structures in two-dimensional, temporally aperiodic flows. We consider both mathematical methods and diagnostic scalar fields, comparing their…

Consistent Recalibration models (CRC) have been introduced to capture in necessary generality the dynamic features of term structures of derivatives' prices. Several approaches have been suggested to tackle this problem, but all of them,…

Computational Finance · Quantitative Finance 2021-07-02 Matteo Gambara , Josef Teichmann

A data-driven procedure for identifying the dominant transport barriers in a time-varying flow from limited quantities of Lagrangian data is presented. Our approach partitions state space into pairs of coherent sets, which are sets of…

Fluid Dynamics · Physics 2015-07-28 Matthew O. Williams , Irina I. Rypina , Clarence W. Rowley

Accurate prediction of Lagrangian trajectories in turbulent flow remains challenging due to limited temporal information in transport functions. This paper shows that surrounding coherent motions sharing the same dynamics carry enough…

Fluid Dynamics · Physics 2026-05-07 Ali R Khojasteh , Dominique Heitz

Lagrangian descriptors provide a global dynamical picture of the geometric structures for arbitrarily time-dependent flows with broad applications. This paper develops a mathematical framework for computing Lagrangian descriptors when…

Fluid Dynamics · Physics 2023-07-11 Nan Chen , Evelyn Lunasin , Stephen Wiggins

Deploying Lagrangian drifters that facilitate the state estimation of the underlying flow field within a future time interval is practically important. However, the uncertainty in estimating the flow field prevents using standard…

Dynamical Systems · Mathematics 2024-02-16 Erik Bollt , Nan Chen , Stephen Wiggins

Estimating continuous optical flow is a fundamental yet challenging problem in dynamic visual perception. Event-based cameras, with microsecond latency and high dynamic range, capture brightness changes asynchronously, offering a unique…

Computer Vision and Pattern Recognition · Computer Science 2026-05-27 Rui Hu , Song Wu , Wen Yang , Jinjian Wu

Lagrangian trajectory or particle dispersion models as well as semi-Lagrangian advection schemes require meteorological data such as wind, temperature and geopotential at the exact spatio-temporal locations of the particles that move…

Atmospheric and Oceanic Physics · Physics 2022-06-09 Rüdiger Brecht , Lucie Bakels , Alex Bihlo , Andreas Stohl

Lagrangian ocean drifters provide highly accurate approximations of ocean surface currents but are sparsely located across the globe. As drifters passively follow ocean currents, there is minimal control on where they will be making…

Dynamical Systems · Mathematics 2019-10-01 Nikolas O. Aksamit , Themistoklis P. Sapsis , George Haller

The reconstruction of physically valid transport fields from subject-specific imaging data is a fundamental challenge in image-based computational modeling due to measurement noise, modeling uncertainties and discretization errors. Without…

Computational Engineering, Finance, and Science · Computer Science 2026-05-04 A. Derya Bakiler , Michael J. Johnson , Michael R. A. Abdelmalik , Frimpong A. Baidoo , Andrew Badachhape , Ananth V. Annapragada , Thomas J. R. Hughes , Shaolie S. Hossain

We assess the influence of different Eulerian geophysical input fields on Lagrangian drift simulations using DriftNet, a learning-based method designed to simulate Lagrangian drift on the sea surface. Two experiments are conducted: a fully…

Atmospheric and Oceanic Physics · Physics 2026-04-07 Daria Botvynko , Carlos Granero-Belinchon , Simon Van Gennip , Abdesslam Benzinou , Ronan Fablet

Reconstructions of Lagrangian drift, for example for objects lost at sea, are often uncertain due to unresolved physical phenomena within the data. Uncertainty is usually overcome by introducing stochasticity into the drift, but this…

Partitioning ocean flows into regions dynamically distinct from their surroundings based on material transport can assist search-and-rescue planning by reducing the search domain. The spectral clustering method partitions the domain by…

Atmospheric and Oceanic Physics · Physics 2020-08-28 Guilherme S. Vieira , Irina I. Rypina , Michael R. Allshouse

Reconstructing ocean dynamics from observational data is fundamentally limited by the sparse, irregular, and Lagrangian nature of spatial sampling, particularly in subsurface and remote regions. This sparsity poses significant challenges…

Atmospheric and Oceanic Physics · Physics 2025-07-10 Niloofar Asefi , Leonard Lupin-Jimenez , Tianning Wu , Ruoying He , Ashesh Chattopadhyay

For oceanographic applications, probabilistic forecasts typically have to deal with i) high-dimensional complex models, and ii) very sparse spatial observations. In search-and-rescue operations at sea, for instance, the short-term…

Applications · Statistics 2023-02-15 Florian Beiser , Håvard Heitlo Holm , Jo Eidsvik

Atmospheric aerosols influence the Earth's climate, primarily by affecting cloud formation and scattering visible radiation. However, aerosol-related physical processes in climate simulations are highly uncertain. Constraining these…

Using a probabilistic neural network and Lagrangian observations from the Global Drifter Program, we model the single particle transition probability density function (pdf) of ocean surface drifters. The transition pdf is represented by a…

Atmospheric and Oceanic Physics · Physics 2023-07-12 Martin T. Brolly