Numerical modeling of displacements due to ocean tide loading: case study at GPS stations in Taiwan and western Pacific

2013 ◽  
Vol 36 (8) ◽  
pp. 1017-1028
Author(s):  
Cheinway Hwanga ◽  
J.F. Huang
Keyword(s):  
Numerical Modeling ◽  
Western Pacific ◽  
Ocean Tide ◽  
Ocean Tide Loading ◽  
Loading Case

scholarly journals ANALYSIS OF OCEAN TIDE LOADING ESTIMATED FROM THE GPS COORDINATE TIME SERIES: A CASE STUDY FOR THE BELÉM, BRASÍLIA, EUSÉBIO, MANAUS AND SANTA MARIA STATIONS, BRAZIL

2019 ◽  
Vol 37 (4) ◽  
pp. 565
Author(s):  
Giuliano Sant’Anna Marotta ◽  
Mário Alexandre De Abreu ◽  
Ana Cristina Oliveira Cancoro De Matos ◽  
João Francisco Galera Monico ◽  
George Sand Leão Araújo De França
Keyword(s):  
Solid Earth ◽  
Earth Tide ◽  
Ocean Tide ◽  
Ocean Tide Loading ◽  
Estimated Parameters ◽  
Celestial Bodies ◽  
Tidal Constituents ◽  
Santa Maria ◽  
Solid Earth Tide

ABSTRACT. The Earth suffers deformations due to the gravitational attraction of the celestial bodies and the redistribution of water mass occurring by the action of the ocean tide. These effects are known as solid Earth tide and ocean tide loading, and can be estimated by observations of the amplitudes and phases of their tidal wave constituents. Considering that GNSS observations may be used to estimate these effects and that the solid Earth tide displacement is well resolved, this work estimated and analyzed the amplitudes and phases of the 11 principal constituents of ocean tide loading, using GPS observations. The methodology was applied to data collected from five stations in Brazil, and the amplitudes and phases of the tidal constituents were estimated and evaluated regarding their values and convergence times. The results showed that most of the estimated parameters converged during the analyzed period. In addition, after correcting the effects of ocean tide loading in each GPS solution, using the computed parameters and the existing models, the coordinates were compared and the results presented some local differences, allowing to recommend the use of GPS to estimate tidal constituents considering the local behavior of the point.Keywords: GPS, ocean tide loading, tidal constituents.RESUMO. A Terra sofre deformações devido à atração gravitacional de corpos celestes e também em função da redistribuição de massa d’água que ocorre por ação da maré oceânica. Estes fenômenos são denominados maré terrestre e carga oceânica, e podem ser estimados por meio das amplitudes e fases das componentes de onda de maré. Considerando que as observações GNSS podem ser usadas na estimativa destes efeitos e que os deslocamentos devido à maré terrestre são teoricamente bem resolvidos, este trabalho estimou e analisou as amplitudes e fases das 11 componentes principais de carga oceânica, utilizando observações GPS. A metodologia foi aplicada a dados coletados em cinco estações instaladas no Brasil, e as amplitudes e fases para as componentes de maré foram estimadas e avaliadas, considerando seus valores e tempo de convergência. Os resultados mostraram que a maioria dos parâmetros estimados convergiu durante o período analisado. Além disso, após corrigir os efeitos de carga oceânica em cada solução GPS, utilizando os parâmetros calculados e os modelos existentes, as coordenadas corrigidas foram comparadas e os resultados apresentaram diferenças locais, permitindo recomendar o uso do GPS na estimativa de componentes de maré considerando o comportamento local do ponto.Palavras-chave: GPS, carga oceânica, componentes de maré.

scholarly journals OCEAN TIDE LOADING AND RELATIVE GNSS IN THE BRITISH ISLES

Survey Review ◽  
2010 ◽  
Vol 42 (317) ◽  
pp. 212-228
Author(s):  
P. J. Clarke ◽  
N. T. Penna
Keyword(s):  
Ocean Tide ◽  
British Isles ◽  
Ocean Tide Loading

scholarly journals An Improved Algorithm for Measuring Nitrate Concentrations in Seawater Based on Deep-Ultraviolet Spectrophotometry: A Case Study of the Aoshan Bay Seawater and Western Pacific Seawater

Sensors ◽  
2021 ◽  
Vol 21 (3) ◽  
pp. 965
Author(s):  
Xingyue Zhu ◽  
Kaixiong Yu ◽  
Xiaofan Zhu ◽  
Juan Su ◽  
Chi Wu
Keyword(s):  
Weighted Average ◽  
Measuring Method ◽  
Western Pacific ◽  
Nitrate Concentrations ◽  
Deep Ultraviolet ◽  
Ultraviolet Spectrometer ◽  
Seawater Samples ◽  
Reflection Probe

Nowadays, it is still a challenge for commercial nitrate sensors to meet the requirement of high accuracy in a complex water. Based on deep-ultraviolet spectral analysis and a regression algorithm, a different measuring method for obtaining the concentration of nitrate in seawater is proposed in this paper. The system consists of a deuterium lamp, an optical fiber splitter module, a reflection probe, temperature and salinity sensors, and a deep-ultraviolet spectrometer. The regression model based on weighted average kernel partial least squares (WA-KPLS) algorithm together with corrections for temperature and salinity (TSC) is established. After that, the seawater samples from Western Pacific and Aoshan Bay in Qingdao, China with the addition of various nitrate concentrations are studied to verify the reliability and accuracy of the method. The results show that the TSC-WA-KPLS algorithm shows the best results when compared against the multiple linear regression (MLR) and ISUS (in situ ultraviolet spectrophotometer) algorithms in the temperatures range of 4–25 °C, with RMSEP of 0.67 µmol/L for Aoshan Bay seawater and 1.08 µmol/L for Western Pacific seawater. The method proposed in this paper is suitable for measuring the nitrate concentration in seawater with higher accuracy, which could find application in the development of in-situ and real-time nitrate sensors.

Sign in / Sign up

Export Citation Format

Share Document