Presenter Information

Bodhi Landry-StahlFollow

Presentation Type

Poster

Faculty Mentor’s Full Name

Hilary Martens

Faculty Mentor’s Department

Geosciences

Abstract

Two factors govern Earth's elastic response to the periodic redistribution of ocean tides: the properties of the crust and upper mantle and the weight of the ocean water loading the surface. Using models for Earth structure and the ocean tides, it is possible to predict surface displacements caused by the tides. I hypothesize that the world's ocean-tide models agree well with one another in the open ocean but disagree at locations with complex coastlines and bathymetry. Tidal models for the open ocean generally have better empirical constraints from satellite altimetry compared to a coastal environment. To test my hypothesis, different ocean tidal models were compared to determine where in the world ocean-tide models differ the most. This was done to identify locations where Global Position System (GPS) observations might be used as an additional dataset to improve the tidal models. Utilizing comparisons between the predicted surface displacement and GPS measurements, it may be possible to put tighter constraints on the ocean-tide models. The tidal models provide estimates of the phase and amplitude of the ocean tide globally. Models with different resolutions have inherent discrepancies because lower resolution models do not have as many data points compared to higher resolution models to sample regions with changing coastlines and bathymetry. Before calculating differences between models I converted amplitude and phase into real and imaginary components and ‘rescaled’ the higher resolution model to match the scaling of the lower resolution model. After calculating the difference, I converted the real and imaginary differences back into amplitude and phase. I plotted the amplitude onto an interactive global map so I could zoom in on particular regions and visually determine where the models are the most discrepant. I found the models to be most discrepant in coastal regions.

Category

Physical Sciences

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Apr 17th, 11:00 AM Apr 17th, 12:00 PM

Investigating Ocean Tidal Models

UC South Ballroom

Two factors govern Earth's elastic response to the periodic redistribution of ocean tides: the properties of the crust and upper mantle and the weight of the ocean water loading the surface. Using models for Earth structure and the ocean tides, it is possible to predict surface displacements caused by the tides. I hypothesize that the world's ocean-tide models agree well with one another in the open ocean but disagree at locations with complex coastlines and bathymetry. Tidal models for the open ocean generally have better empirical constraints from satellite altimetry compared to a coastal environment. To test my hypothesis, different ocean tidal models were compared to determine where in the world ocean-tide models differ the most. This was done to identify locations where Global Position System (GPS) observations might be used as an additional dataset to improve the tidal models. Utilizing comparisons between the predicted surface displacement and GPS measurements, it may be possible to put tighter constraints on the ocean-tide models. The tidal models provide estimates of the phase and amplitude of the ocean tide globally. Models with different resolutions have inherent discrepancies because lower resolution models do not have as many data points compared to higher resolution models to sample regions with changing coastlines and bathymetry. Before calculating differences between models I converted amplitude and phase into real and imaginary components and ‘rescaled’ the higher resolution model to match the scaling of the lower resolution model. After calculating the difference, I converted the real and imaginary differences back into amplitude and phase. I plotted the amplitude onto an interactive global map so I could zoom in on particular regions and visually determine where the models are the most discrepant. I found the models to be most discrepant in coastal regions.