Tesis Postgrado

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https://repositoriobibliotecas.uv.cl/handle/uvscl/16619

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Comparison of QuikSCAT, WRF and buoy ocean surface wind data off Valparaiso Bay, Chile
(Journal of Marine Systems, 2020) Cáceres Muñoz, Mario; Sepúlveda . H. H; Muñoz Mellado, K; Artal, O
The winds that affect the surface of the ocean are also important for a vast array of activities, either operational or scientific, hence the importance of being able to adequately predict this quality. Because of the preceding fact, a Weather Research and Forecasting model was used to perform simulations at the surface of the Ocean, forwinds derived from different boundary conditions (NCEP-CFSR, ERA-Interim and NCEP-FNL) and configured with different spatial resolution (25, 5 and 1 km), with the objective of evaluating which of these data sets delivers the more precise wind simulation at the surface of the ocean. A comparative analysis was performed between the different outputs of the WRF model, QuikSCAT satellite and in situ observations of a buoy installed off the central coast of Chile. The results showed that the WRF model, overestimates the wind magnitudes, across all boundary conditions or spatial resolution. Additionally, depending on the in situ wind magnitude (> 6 ms−1), the model predicts adequately wind magnitude and direction. Spatial comparisons were performed between QuikSCAT and WRF outputs at the Chilean coast to evaluate any possible differences. The modeled winds showed a tendency to be stronger than those measured by Satellites and the bigger differences appeared closer to the shore. The wavelet coherence and phase analysis, confirmed that the model delivers precise wind information for frequencies greater than the daily cycle. Finally, the results of the simulation produced by the ERA-Interim analysis showed lower errors in terms of temporal and spatial variability of surface winds.
Environmental determinants in morphospace and diet of the larval blenny Calliclinus geniguttatus from an upwelling ecosystem.
(Universidad de Valparaíso, 2020) Galeano Chavarría, Ana María; Landaeta Díaz, Mauricio
The effects of two contrasting environmental conditions in nearshore waters off cen tral Chile on the diet and morphospace of two cohorts of larval labrisomid blenny Cal liclinus geniguttatus were studied using geometric morphometrics and gut content analysis. The two environmental conditions corresponded to (a) a cold period with upwelling-favourable southwesterly winds and a mixed water column of cooler water and (b) a warm period with calm winds and stratified warmer water. During the cold period, fish larvae had a more hydrodynamic head shape, longer jaws and a higher feeding incidence, suggesting a greater food supply due to upwelling events and a possible increase in encounter rates in the turbulent environment. In contrast, the lar vae from the warm period had a more robust head shape with smaller jaws and a lower feeding incidence, which was related to higher water temperatures and lower wind intensities. The present study suggests that larvae have a rapid response to environmental changes on a short time scale (i.e., from weeks to months), showing a link between environmental conditions and changes in the phenotypic traits and diet of the larval stages of this cryptobenthic species
Simulating the copper distribution in coastal waters and sediments in Quintero Bay and adjacent shores
(Marine Pollution Bulletin, 2026) Ord, Gillian K.; Caceres Muñoz , Mario
This study presents a 3D hydrodynamic simulation of coastal circulation coupled with copper advection emanating from Quintero Bay, in the Valparaíso region. The bay is home to an important industrial complex and has a history of heavy metal contamination due to a copper smelter located in its northern sector. This study aims to simulate the distribution of contamination from existing sources and identify potential risk scenarios associated with copper exposure in water and sediment. A simple data assimilation method has been developed to capture elements of coastal wind not well represented by existing models used for wind forcing. The simulation period represents an austral summer, and several circulation patterns have been identified in response to external forcings. Two different point sources are considered, one within the bay (source 1), and the other just outside the south side of the bay (source 2). Simulations show advection of copper towards coastal areas north of the bay in trace concentrations from both sources, with instances at certain points within the bay when recommended thresholds for chronic and acute exposure are surpassed. Source 1 shows advection predominantly leaving the north side of the bay in surface waters, while source 2 shows advection in bottom waters periodically entering the south side of the bay. These results are consistent with existing local studies of copper concentrations in the water and sediment.
Upgrade of the Chilean Wave Atlas database
(Ocean Modelling, 2025) Correa Araya, Sebastián; Aguirre, Catalina; Becerra, Diego; Molina, Mauricio; Vilchez, Pablo; Bahamóndez, Sergio
The Chilean Wave Atlas (AOC1), a reliable hindcast developed in 2017 for the academic and engineering community, diminished its usefulness due to the obsolescence of wind data provided by ERA-Interim reanalysis. This study presents the calibration and validation of a new wave hindcast forced using hourly winds data from ERA5 reanalysis. A total of 24 simulations were conducted: 15 using the semi-empirical ST4 parameterization and 9 using the observed-based ST6 parameterization, both implemented in WaveWatch III. Model results were compared with in-situ wave data from buoys along the Chilean coast. Generally, the ST4 physics package demonstrated superior performance with minimal variability in error statistical parameters between simulations. However, the observed-based ST6 parameterization produced the best results for simulating wave direction. By defining a multi-criteria performance score, the optimal model configuration was selected, and a new hindcast was generated for the period between 1979 and 2022. This hindcast includes hourly fields of significant wave height, mean and peak wave period, and mean and peak wave direction for the Pacific Ocean, as well as 72 locations with directional spectra. The upgraded Chilean Wave Atlas (AOC3) significantly improves the performance of AOC1 when compared with satellite-derived wave heights along the Chilean coast. Furthermore, the AOC3 data show good performance compared to other freely available hindcasts.

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