Observing and Quantifying Kinematic Properties and Lagrangian Coherent Structures of Ocean Flows using Drifter Experiments
This thesis analyzes data from two types of unique drifter experiments in order to characterize two aspects of ocean flows that are often difficult to study. First, vertical velocities and their associated transport processes are often challenging to observe in the real ocean since vertical velociti...
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| Format: | Thesis |
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Massachusetts Institute of Technology
2022
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| Online Access: | https://hdl.handle.net/1721.1/139904 |
| _version_ | 1811076388118069248 |
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| author | Getscher, Timothy |
| author2 | Rypina, Irina |
| author_facet | Rypina, Irina Getscher, Timothy |
| author_sort | Getscher, Timothy |
| collection | MIT |
| description | This thesis analyzes data from two types of unique drifter experiments in order to characterize two aspects of ocean flows that are often difficult to study. First, vertical velocities and their associated transport processes are often challenging to observe in the real ocean since vertical velocities are typically orders of magnitude smaller than horizontal velocities in mesoscale and submesoscale flows. Second, Lagrangian coherent structures (LCS) are features which categorize ocean flows into regimes of distinct behavior. These structures are also difficult to quantify in the real ocean, since sets of gridded trajectories from real ocean data (rather than model fields) are rarely available.
The first experiment uses drifters drogued at multiple depths in the Alboran Sea to observe and characterize the ocean’s vertical structure, particularly near a strong front where vertical velocities are expected to be much stronger than other regions of the Ocean. The second experiment uses a roughly gridded pattern of surface drifters in the Gulf of Mexico to study LCSs as quantified by methods from dynamical systems such as finitetime Lyapunov exponents (FTLEs), trajectory arc-length, correlation dimension, dilation, Lagrangian-averaged vorticity deviation (LAVD), and spectral clustering. This thesis includes the first attempt to apply these dynamical systems techniques to real drifters for LCS detection.
Overall, these experiments and the methods used in this paper are shown to be promising new techniques for quantifying both the vertical structure of ocean flows and Lagrangian Coherent Structures of flows using real drifter data. Future work may involve modified versions of the experiments, with denser sets of ocean drifters in the horizontal and/or vertical directions. |
| first_indexed | 2024-09-23T10:20:40Z |
| format | Thesis |
| id | mit-1721.1/139904 |
| institution | Massachusetts Institute of Technology |
| last_indexed | 2024-09-23T10:20:40Z |
| publishDate | 2022 |
| publisher | Massachusetts Institute of Technology |
| record_format | dspace |
| spelling | mit-1721.1/1399042022-02-08T03:50:49Z Observing and Quantifying Kinematic Properties and Lagrangian Coherent Structures of Ocean Flows using Drifter Experiments Getscher, Timothy Rypina, Irina Joint Program in Oceanography/Applied Ocean Science and Engineering Massachusetts Institute of Technology. Department of Earth, Atmospheric, and Planetary Sciences This thesis analyzes data from two types of unique drifter experiments in order to characterize two aspects of ocean flows that are often difficult to study. First, vertical velocities and their associated transport processes are often challenging to observe in the real ocean since vertical velocities are typically orders of magnitude smaller than horizontal velocities in mesoscale and submesoscale flows. Second, Lagrangian coherent structures (LCS) are features which categorize ocean flows into regimes of distinct behavior. These structures are also difficult to quantify in the real ocean, since sets of gridded trajectories from real ocean data (rather than model fields) are rarely available. The first experiment uses drifters drogued at multiple depths in the Alboran Sea to observe and characterize the ocean’s vertical structure, particularly near a strong front where vertical velocities are expected to be much stronger than other regions of the Ocean. The second experiment uses a roughly gridded pattern of surface drifters in the Gulf of Mexico to study LCSs as quantified by methods from dynamical systems such as finitetime Lyapunov exponents (FTLEs), trajectory arc-length, correlation dimension, dilation, Lagrangian-averaged vorticity deviation (LAVD), and spectral clustering. This thesis includes the first attempt to apply these dynamical systems techniques to real drifters for LCS detection. Overall, these experiments and the methods used in this paper are shown to be promising new techniques for quantifying both the vertical structure of ocean flows and Lagrangian Coherent Structures of flows using real drifter data. Future work may involve modified versions of the experiments, with denser sets of ocean drifters in the horizontal and/or vertical directions. S.M. 2022-02-07T15:11:48Z 2022-02-07T15:11:48Z 2021-09 2021-10-19T13:40:20.344Z Thesis https://hdl.handle.net/1721.1/139904 In Copyright - Educational Use Permitted Copyright retained by author(s) https://rightsstatements.org/page/InC-EDU/1.0/ application/pdf Massachusetts Institute of Technology |
| spellingShingle | Getscher, Timothy Observing and Quantifying Kinematic Properties and Lagrangian Coherent Structures of Ocean Flows using Drifter Experiments |
| title | Observing and Quantifying Kinematic Properties and Lagrangian Coherent Structures of Ocean Flows using Drifter Experiments |
| title_full | Observing and Quantifying Kinematic Properties and Lagrangian Coherent Structures of Ocean Flows using Drifter Experiments |
| title_fullStr | Observing and Quantifying Kinematic Properties and Lagrangian Coherent Structures of Ocean Flows using Drifter Experiments |
| title_full_unstemmed | Observing and Quantifying Kinematic Properties and Lagrangian Coherent Structures of Ocean Flows using Drifter Experiments |
| title_short | Observing and Quantifying Kinematic Properties and Lagrangian Coherent Structures of Ocean Flows using Drifter Experiments |
| title_sort | observing and quantifying kinematic properties and lagrangian coherent structures of ocean flows using drifter experiments |
| url | https://hdl.handle.net/1721.1/139904 |
| work_keys_str_mv | AT getschertimothy observingandquantifyingkinematicpropertiesandlagrangiancoherentstructuresofoceanflowsusingdrifterexperiments |