Record Details
Field | Value |
---|---|
Title | Prediction of tidal propagation and circulation in Chilean Inland Seas using a frequency domain model |
Names |
Nunez, Rodrigo H.
(creator) Neshyba, Steve (advisor) |
Date Issued | 1990-08-03 (iso8601) |
Note | Graduation date: 1991 |
Abstract | The calculated flow field and tide wave propagation in the Chilean Inland Seas is modeled with a non-linear tidal embayment method (TEA-NL, Westerink et al, 1988) and assimilation of tide records of the Chilean Hydrographic Institute. Model is validated for two test cases with assimilated error-free boundary conditions. An Inverse Tidal Method (I. T. M.) developed as a time-domain method by Bennett and McIntosh in 1982, is used to calculate the forcing functions, but in the frequency-domain instead. The model is first run using all available tide data. A second run with a subset of five stations shows how the choice and location of stations affect the prediction of tide wave propagation and flow fields. The boundary conditions calculated by the I. T. M. for the cases of seven and five stations reproduced the known data at the stations with like error magnitudes. However, for the seven stations case, the tide wave propagation along the seaward side of Chiloe Island (Pacific Ocean) propagated from South to North (the known direction of propagation is from North to South). After disregarding two stations, the model gave tide waves along the seaward side of Chloe Island propagating from North to South. The model is clearly sensitive to perturbations introduced by hydraulics factors other than pure tide wave propagation. Charts of model simulation of flow fields are shown at 3, 6, 9 and 12 hours of the M2 tidal cycle. Charts of phases and amplitudes are also shown. Conclusions from the study are that the I. T. M. is a good data assimilation technique to calculate the forcing functions of a numerical model, even when known data is scarce. Further, the I. T. M. is a valuable aid in choosing locations for new and useful data to improve the simulation. Next steps required to improve the understanding of the Chilean Inland Seas are a good field survey (based on the results of the I. T. M.), the development of a transport model against which measured flow data can be compared, the inclusion of river discharge in the boundary conditions, the preparation of trajectory charts to demonstrate particle diffusion and advection, the expansion to three-dimensional models, etc. |
Genre | Thesis/Dissertation |
Topic | Tides -- Chile -- Mathematical models |
Identifier | http://hdl.handle.net/1957/23532 |