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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

Inspired by spatiotemporal observations from satellites of the trajectories of objects drifting near the surface of the ocean in the National Oceanic and Atmospheric Administration's `Global Drifter Program', this paper develops data-driven…

Chaotic Dynamics · Physics 2018-10-19 François Gay-Balmaz , Darryl D. Holm

Argo floats measure seawater temperature and salinity in the upper 2,000 m of the global ocean. Statistical analysis of the resulting spatio-temporal dataset is challenging due to its nonstationary structure and large size. We propose…

Applications · Statistics 2018-12-31 Mikael Kuusela , Michael L. Stein

We provide a novel methodology for computing the most likely path taken by drifters between arbitrary fixed locations in the ocean. We also provide an estimate of the travel time associated with this path. Lagrangian pathways and travel…

Applications · Statistics 2021-06-16 Michael O'Malley , Adam M. Sykulski , Romuald Laso-Jadart , Mohammed-Amin Madoui

We propose a new class of univariate nonstationary time series models, using the framework of modulated time series, which is appropriate for the analysis of rapidly-evolving time series as well as time series observations with missing…

We analyze characteristics of drifter trajectories from the Adriatic Sea with recently introduced nonlinear dynamics techniques. We discuss how in quasi-enclosed basins, relative dispersion as function of time, a standard analysis tool in…

chao-dyn · Physics 2007-05-23 Guglielmo Lacorata , Erik Aurell , Angelo Vulpiani

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…

We introduce a nonstationary spatio-temporal statistical model for gridded data on the sphere. The model specifies a computationally convenient covariance structure that depends on heterogeneous geography. Widely used statistical models on…

Applications · Statistics 2016-02-25 Stefano Castruccio , Joseph Guinness

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. We aim at reconstructing the four-dimensional…

Optimization and Control · Mathematics 2009-11-13 Maëlle Nodet

The purpose of this paper is to examine the Lagrangian stochastic modeling of the fluid velocity seen by inertial particles in a nonhomogeneous turbulent flow. A new Langevin-type model, compatible with the transport equation of the drift…

Fluid Dynamics · Physics 2009-07-01 Boris Arcen , Anne Tanière

Lagrangian data assimilation exploits the trajectories of moving tracers as observations to recover the underlying flow field. One major challenge in Lagrangian data assimilation is the intrinsic nonlinearity that impedes using exact…

Dynamical Systems · Mathematics 2023-06-14 Nan Chen , Shubin Fu

Many records in environmental sciences exhibit asymmetric trajectories and there is a need for simple and tractable models which can reproduce such features. In this paper we explore an approach based on applying both a time change and a…

Methodology · Statistics 2015-10-09 Pierre Ailliot , Bernard Delyon , Valérie Monbet , Marc Prevosto

This work aims at generating a model of the ocean surface and its dynamics from one or more video cameras. The idea is to model wave patterns from video as a first step towards a larger system of photogrammetric monitoring of marine…

Computer Vision and Pattern Recognition · Computer Science 2013-10-01 Mauro de Amorim , Ricardo Fabbri , Lucia Maria dos Santos Pinto , Francisco Duarte Moura Neto

We address Lagrangian drift simulation in geophysical dynamics and explore deep learning approaches to overcome known limitations of state-of-the-art model-based and Markovian approaches in terms of computational complexity and error…

Machine Learning · Computer Science 2022-11-21 Daria Botvynko , Carlos Granero-Belinchon , Simon Van Gennip , Abdesslam Benzinou , Ronan Fablet

Lagrangian averaging has been shown to be more effective than Eulerian mean in separating waves from slow dynamics in two-timescale flows. It also appears in many reduced models that capture the wave feedback on the slow flow. Its…

Fluid Dynamics · Physics 2022-04-20 Hossein Kafiabad

A method for extracting time-varying oscillatory motions from time series records is applied to Lagrangian trajectories from a numerical model of eddies generated by an unstable equivalent barotropic jet on a beta plane. An oscillation in a…

Atmospheric and Oceanic Physics · Physics 2015-05-30 Jonathan M. Lilly , Richard K. Scott , Sofia C. Olhede

Upper-ocean turbulent flows at horizontal length scales smaller than the deformation radius depart from geostrophic equilibrium and develop important vertical velocities, which are key to marine ecology and climatic processes. Due to their…

Fluid Dynamics · Physics 2023-12-04 Michael Maalouly , Guillaume Lapeyre , Bastien Cozian , Gilmar Mompean , Stefano Berti

A dataset of sea surface temperature (SST) estimates is generated from the temperature observations of surface drifting buoys of NOAA's Global Drifter Program. Estimates of SST at regular hourly time steps along drifter trajectories are…

Atmospheric and Oceanic Physics · Physics 2022-09-01 Shane Elipot , Adam Sykulski , Rick Lumpkin , Luca Centurioni , Mayra Pazos

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

In this work, a stochastic representation based on a physical transport principle is proposed to account for mesoscale eddy effects on the large-scale oceanic circulation. This stochastic framework arises from a decomposition of the…

Geophysics · Physics 2022-07-26 Long Li , Bruno Deremble , Noé Lahaye , Etienne Mémin
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