Monsoon-Induced Surge during High Tides at the Southeast Coast of Vietnam: A Numerical Modeling Study

In this study, monsoon-induced surge during high tides at the Southeast coast of Vietnam was analyzed based on the observed tide data at the Vung Tau station in the period between 1997—2016. Specifically, the surge was determined by removing the astronomical tide from the observed total water level. The two-dimensional Regional Ocean Model System (ROMS 2D) was applied to simulate the surge induced by monsoons during spring tide. The surge observations showed that the change of peak surge did not follow a clear trend, of either an increase or decrease, over time. A peak surge of over 40 cm appeared mainly in October and November, although the peak of the astronomical tide was higher in December. ROMS 2D was validated with the observational data, and the model could sufficiently reproduce the wind-induced surge during high tides. This study therefor ere commends for ROMS 2D to be used in operational forecasts in this area.

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Radiational tides: their double-counting in storm surge forecasts and contribution to the Highest Astronomical Tide

Ocean Science ◽

10.5194/os-14-1057-2018 ◽

2018 ◽

Vol 14 (5) ◽

pp. 1057-1068 ◽

Cited By ~ 5

Author(s):

Joanne Williams ◽

Maialen Irazoqui Apecechea ◽

Andrew Saulter ◽

Kevin J. Horsburgh

Keyword(s):

Tide Gauge ◽

Storm Surges ◽

Double Counting ◽

Atmospheric Conditions ◽

Sea Level Changes ◽

Astronomical Tide ◽

Operational Forecasts ◽

The Difference ◽

The Uk ◽

Total Water Level

Abstract. Tide predictions based on tide-gauge observations are not just the astronomical tides; they also contain radiational tides – periodic sea-level changes due to atmospheric conditions and solar forcing. This poses a problem of double-counting for operational forecasts of total water level during storm surges. In some surge forecasting, a regional model is run in two modes: tide only, with astronomic forcing alone; and tide and surge, forced additionally by surface winds and pressure. The surge residual is defined to be the difference between these configurations and is added to the local harmonic predictions from gauges. Here we use the Global Tide and Surge Model (GTSM) based on Delft-FM to investigate this in the UK and elsewhere, quantifying the weather-related tides that may be double-counted in operational forecasts. We show that the global S2 atmospheric tide is captured by the tide-and-surge model and observe changes in other major constituents, including M2. The Lowest and Highest Astronomical Tide levels, used in navigation datums and design heights, are derived from tide predictions based on observations. We use our findings on radiational tides to quantify the extent to which these levels may contain weather-related components.

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Implementation and Validating of the Regional Ocean Model System (ROMS) for the Sunda Strait connecting the Java Sea to the Indian Ocean

10.5194/egusphere-egu21-3457 ◽

2021 ◽

Author(s):

Subekti Mujiasih ◽

Jean-Marie Beckers ◽

Alexander Barth

Keyword(s):

Time Series ◽

Indian Ocean ◽

Vertical Profile ◽

Ocean Model ◽

Model System ◽

Satellite Sst ◽

Regional Ocean Model System ◽

Regional Ocean Model ◽

The Indian Ocean ◽

Java Sea

Regional Ocean Model System (ROMS) has been simulated for the Sunda Strait, the Java Sea, and the Indian Ocean. The simulation was undertaken for thirteen months of data period (August 2013 &#8211; August 2014). However, we only used four months period for validation, namely September &#8211; December 2013. The input data involved the HYbrid Coordinate Ocean Model (HYCOM) ocean model output by considering atmospheric forcing from the European Centre for Medium-Range Weather Forecasts (ECMWF), without and with tides forcing from TPXO and rivers. The output included vertical profile temperature and salinity, sea surface temperature (SST), seas surface height (SSH), zonal (u), and meridional (v) velocity. We compared the model SST to satellite SST in time series, SSH to tides gauges data in time series, the model u and v component velocity to High Frequency (HF) radial velocity. The vertical profile temperature and salinity were compared to Argo float data and XBT. Besides, we validated the amplitude and phase of the ROMS seas surface height to amplitude and phase of the tides-gauges, including four constituents (M2, S2, K1, O1).

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Application of HY-2 Satellite SST Data in 4D Variational Assimilation Ocean Forecast Model

International Journal of Distributed Systems and Technologies ◽

10.4018/ijdst.2017040102 ◽

2017 ◽

Vol 8 (2) ◽

pp. 15-26

Author(s):

Zhenchang Zhang ◽

Libin Gao ◽

Minquan Guo ◽

Riqing Chen

Keyword(s):

Time Window ◽

Forecast Model ◽

Ocean Model ◽

Satellite Sst ◽

Regional Ocean Model System ◽

Model Research ◽

Numerical Ocean Model ◽

Regional Ocean Model ◽

Taiwan Straits ◽

Marine Environmental

The 4D variational (4DVAR) assimilation numerical ocean model research is proposed. This model for Taiwan Straits (TWS) is based on Regional Ocean Model System (ROMS). The background of the 4DVAR method is introduced and the development process of assimilation system is presented. In the present research, the model assimilated with Sea Surface Temperature (SST) data of HY-2 satellite (Qi, 2012; Xu, 2013) which is the first marine environmental monitoring satellite of China. In this paper, the model processes from Feb. 1 to Feb. 7, 2014 with one-day assimilation time window and root mean square error (RMSE) reduces averagely by 14.7%.

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Assimilation of Middepth Velocities from Argo Floats in the Western South China Sea

Journal of Atmospheric and Oceanic Technology ◽

10.1175/jtech-d-18-0233.1 ◽

2020 ◽

Vol 37 (1) ◽

pp. 141-157

Author(s):

Pinqiang Wang ◽

Weimin Zhang ◽

Huizan Wang ◽

Haijin Dai ◽

Xiaohui Wang

Keyword(s):

Data Assimilation ◽

South China Sea ◽

South China ◽

Ocean Model ◽

Trajectory Data ◽

Argo Float ◽

Argo Floats ◽

China Sea ◽

Regional Ocean Model System ◽

Regional Ocean Model

AbstractPrevious studies are mainly limited to temperature and salinity (T/S) profiling data assimilation, while data assimilation based on Argo float trajectory information has received less research focus. In this study, a new method was proposed to assimilate Argo trajectory data: the middepth (indicates the parking depth of Argo floats in this study, ~1200 m) velocities are estimated from Argo trajectories and subsequently assimilated into the Regional Ocean Model System (ROMS) using four-dimensional variational data assimilation (4DVAR) method. This method can avoid a complicated float trajectory model in direct position assimilation. The 2-month assimilation experiments in South China Sea (SCS) showed that this proposed method can effectively assimilate Argo trajectory information into the model and improve middepth velocity field by adjusting the unbalanced component in the velocity increments. The assimilation of the Argo trajectory-derived middepth velocity with other observations (satellite observations and T/S profiling data) together yielded the best performance, and the velocity fields at the float parking depth are more consistent with the Argo float trajectories. In addition, this method will not decrease the assimilation performance of other observations [i.e., sea level anomaly (SLA), sea surface temperature (SST), and T/S profiles], which is indicative of compatibility with other observations in the 4DVAR assimilation system.

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Ensemble Water Level Prediction System: Improving the Representation of Model Uncertainty

10.5194/egusphere-egu2020-22142 ◽

2020 ◽

Author(s):

Natacha Bernier ◽

Oleksandr Huziy ◽

Keith Thompson ◽

Pengcheng Wang ◽

Benoit Pouliot ◽

...

Keyword(s):

Water Level ◽

Gulf Of Maine ◽

Ocean Model ◽

Total Water ◽

Atmospheric Forcing ◽

Operational Forecasts ◽

Recent Case Study ◽

Coastal Water Level ◽

Total Water Level

Concern over increased flooding and the need for earlier and more reliable risk forecasts motivate the continued development of operational forecasts of coastal water level. We report here on results from a year long ensemble of total water level forecasts calculated using a dynamical ocean model forced with ensemble atmospheric forcing and tidal boundary conditions. We focus on the east coast of Canada. The domain includes the Gulf of St. Lawrence, the Labrador Shelf, the Scotian Shelf, and the Gulf of Maine. The water level ensemble is made of a control and 20 perturbed members. Individual forecasts are produced twice daily for 16 days.&#160;The novelty of the present study is in the exploration of perturbations of the ocean contributions. In addition to examining how uncertainty in atmospheric forcing maps into flood risk, we also explore the feasibility, and impact, of perturbing the ocean tides. We use a recent case study to demonstrate our findings.&#160;

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Tidal effects on ichthyoplankton aggregation and dispersion in the Southern Gulf of Mexico

Brazilian Journal of Oceanography ◽

10.1590/s1679-87592013000400004 ◽

2013 ◽

Vol 61 (4) ◽

pp. 231-241 ◽

Cited By ~ 1

Author(s):

María Adela Monreal Gómez ◽

David Alberto Salas de León ◽

Cesar Flores Coto ◽

Fernando Flores Hernández ◽

David Salas Monreal ◽

...

Keyword(s):

Gulf Of Mexico ◽

Single Point ◽

Internal Tide ◽

Ocean Model ◽

Hydraulic Control ◽

Barotropic Tide ◽

Regional Ocean Model System ◽

Southern Gulf Of Mexico ◽

Regional Ocean Model

The role of vertical barotropic and baroclinic tidal forcing in the aggregation and dispersion of ichthyoplankton in the Southern Gulf of Mexico was analyzed in this study. Samplings of ichthyoplankton and the determination of hydrographic parameters were performed during September 1992 at a single point of 180 m depth, near the shelf break (19º32'N - 92º38.5'W). A 24 h CTD yo-yoing casting and biological samples were taken every 2 h and these measurements were combined with water velocity and density simulations from the Regional Ocean Model System (ROMS). One thermocline and two haloclines were depicted. The Froude number increased with a 2 h lag with respect to the maximal barotropic tide, suggesting the existence of a baroclinic tide. Aggregation and dispersion of the ichthyoplankton showed vertical oscillations in the abundance and the numbers of taxa and larvae with a 5 h lag with respect to the maximal barotropic tide and were in phase with the thermocline oscillation. The vertical oscillation was attributed to a hydraulic control forced by the internal tide.

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Storm surge forecasting: quantifying errors arising from the double-counting of radiational tides

10.5194/os-2018-63 ◽

2018 ◽

Cited By ~ 1

Author(s):

Joanne Williams ◽

Maialen Irazoqui Apecechea ◽

Andrew Saulter ◽

Kevin J. Horsburgh

Keyword(s):

Tide Gauge ◽

Storm Surges ◽

Double Counting ◽

Atmospheric Conditions ◽

Sea Level Changes ◽

Astronomical Tide ◽

Operational Forecasts ◽

The Difference ◽

The Uk ◽

Total Water Level

Abstract. Tide predictions based on tide-gauge observations are not just the astronomical tides, they also contain radiational tides – periodic sea level changes due to atmospheric conditions and solar forcing. This poses a problem of double-counting for operational forecasts of total water level during storm surges. In some surge forecasting, a regional model is run as tide-only, with astronomic forcing alone; and tide-and-surge, forced additionally by surface winds and pressure. The surge residual is defined to be the difference between these configurations and is added to the local harmonic predictions from gauges. Here we use the Global Tide and Surge Model based on Delft-FM to investigate this in the UK and elsewhere, quantifying the weather-related tides that may be double-counted in operational forecasts. We show that the global S2 atmospheric tide is captured by the tide-surge model, and observe changes in other key constituents, including M2. We also quantify the extent to which the Highest Astronomical Tide, which is derived from tide predictions based on observations, may contain weather-related components.

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АПВЕЛЛИНГ НА УЗКОМ ШЕЛЬФЕ ЯПОНСКОГО МОРЯ В 2011 Г., "Фундаментальная и прикладная гидрофизика"

Фундаментальная и прикладная гидрофизика ◽

10.7868/s2073667321010032 ◽

2021 ◽

pp. 31-42

Author(s):

А.В. Кошелева ◽

И.О. Ярощук ◽

Ф.Ф. Храпченков ◽

A. A. Pivovarov ◽

А.Н. Самченко ◽

...

Keyword(s):

Ocean Model ◽

Model System ◽

Regional Ocean Model System ◽

Regional Ocean Model

На основе инструментальных и спутниковых наблюдений рассматриваются характерные особенности локального апвеллинга, наблюдавшегося в октябре 2011 г. в юго-западной части залива Петра Великого Японского моря. Кроме того, приведены результаты численного моделирования, выполнявшегося при помощи Regional Ocean Model System (ROMS) со свободной поверхностью. При вычислениях использовались метеорологические наблюдения за неоднородностями поля ветра и инструментальные измерения гидрологической структуры воды. Анализ данных натурных измерений и их сравнение с результатами моделирования развития апвеллинга выявили, что пространственный и временной масштаб явления определялся силой, продолжительностью и направлением воздействующего ветра. Неоднородность поля скорости ветра, тесно связанная с особенностями береговой орографии, приводит к усилению апвеллинга у некоторых частей побережья и формированию температурных фронтов и струй холодной воды, поперечных основному течению, идущему вдоль шельфа.

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Demonstrating the potential of Regional Ocean Model System in simulating the upper ocean characteristic over Arabian Sea: impact of horizontal resolution

10.21203/rs.3.rs-792515/v1 ◽

2021 ◽

Author(s):

Prabha Kushwaha ◽

Vivek Kumar Pandey

Keyword(s):

Arabian Sea ◽

Horizontal Resolution ◽

Ocean Model ◽

Model System ◽

Sea Surface ◽

Sea Surface Salinity ◽

Surface Salinity ◽

Regional Ocean Model System ◽

Regional Ocean Model ◽

The Impact

Abstract This study attempted to demonstrate the skill of the regional ocean model system (ROMS) is simulating the hydrographic property of the Arabian Sea (AS). Additionally, the impact of horizontal resolution is investigated. In this regard, ROMS is integrated over AS covering [30˚E-80˚E; 5˚N-30N˚] at two different horizontal resolutions 1/6˚(~ 17km) and 1/4˚(~ 25km) for ten years. The comparison of model results with available observation and reanalysis indicates reasonable resemblances in reproducing the spatial-temporal distribution of surface and subsurface hydrographic property i.e. sea surface temperature (SST), sea surface salinity (SSS), sea surface currents, and subsurface temperature and salinity at both resolutions. The increasing resolution shows minimal improvement, indicating the fact that its not always guaranty to enhance the performance towards increasing resolution for every aspect.

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