Modelling and mitigation of real-time sea level measurement over the coastal area of Japan

2021 ◽  
Vol 42 (4) ◽  
Author(s):  
Kutubuddin Ansari ◽  
Tae-Suk Bae
Keyword(s):  
Real Time ◽  
Sea Level ◽  
Coastal Area ◽  
Level Measurement

scholarly journals Analisa Kinerja IDSL/PUMMA untuk Peringatan Dini Tsunami di Pangandaran

2021 ◽  
Vol 16 (2) ◽  
pp. 87
Author(s):  
Semeidi Husrin ◽  
Dian Novianto ◽  
Rikha Bramawanto ◽  
Agus Setiawan ◽  
Dwiyoga Nugroho ◽  
...  
Keyword(s):  
Real Time ◽  
Sea Level ◽  
Level Measurement ◽  
Cctv Camera

Salah satu alat untuk peringatan dini tsunami, IDSL (Inexpensive Device for Sea Level Measurement) atau PUMMA (Perangkat Ukur Murah untuk Muka Air laut) yang merupakan sebuat stasiun pasang surut real-time telah terpasang di Pantai Pangandaran sejak Oktober 2019. Tulisan ini bertujuan untuk menganalisa kinerja IDSL/PUMMA berdasarkan parameter-parameter penting untuk peringatan dini tsunami seperti kerapatan data, kecepatan transmisi data, kualitas gambar CCTV camera, dan kemampuan memberikan peringatan dini itu sendiri. Data selama 9 bulan pertama berhasil dianalisa berdasarkan parameter-parameter tersebut diperkuat dengan pemodelan tsunami di Selatan Jawa menggunakan model numrik COMCOT. Hasil analisa memperlihatkan bahwa IDSL/PUMMA bekerja dengan baik dengan memberikan data valid dengan kerapatan setiap 10 detik sebanyak lebih dari 91% dengan kecepatan transmisi data di bawah 25 detik (99%). Sementara itu, gambar CCTV camera dengan kualitas baik dan sedang mencapai 69%. Berdasarkan hasil pemodelan tsunami, deteksi langsung anomali muka air tidak dapat dilakukan kurang dari 5 menit. Namun, peringatan dini tsunami berpotensi dikeluarkan melalui guncangan atau pergerakan anjungan stasiun pasang surut yang diakibatkan oleh gempabumi. Berdasarkan hasil analisa kinerja secara keseluruhan,  IDSL/PUMMA dan sistem sejenis lainnya sangat layak untuk dijadikan penguat sistem peringatan dini tsunami di Indonesia.

Myanmar Coastal Area Field Survey after the December 2004 Indian Ocean Tsunami

2006 ◽  
Vol 22 (3_suppl) ◽  
pp. 285-294 ◽  
Author(s):  
Tint Lwin Swe ◽  
Kenji Satake ◽  
Than Tin Aung ◽  
Yuki Sawai ◽  
Yukinobu Okamura ◽  
...  
Keyword(s):  
Indian Ocean ◽  
Real Time ◽  
West Coast ◽  
Coastal Area ◽  
Field Survey ◽  
Indian Ocean Tsunami ◽  
Sumatra Earthquake ◽  
The West ◽  
Tide Level ◽  
The Indian Ocean

A post-tsunami survey was conducted along the Myanmar coast two months after the 2004 Great Sumatra earthquake ( Mw=9.0) that occurred off the west coast of Sumatra and generated a devastating tsunami around the Indian Ocean. Visual observations, measurements, and a survey of local people's experiences with the tsunami indicated some reasons why less damage and fewer casualties occurred in Myanmar than in other countries around the Indian Ocean. The tide level at the measured sites was calibrated with reference to a real-time tsunami datum, and the tsunami tide level range was 2–3 m for 22 localities in Myanmar. The tsunami arrived three to four hours after the earthquake.

scholarly journals Sea-level prediction for early warning information of coastal inundation in Belawan coastal area using Delft3D model

2021 ◽  
Vol 893 (1) ◽  
pp. 012034
Author(s):  
A M N Jaya ◽  
F P Sari ◽  
I J A Saragih ◽  
I Dafitra
Keyword(s):  
Water Level ◽  
Sea Level ◽  
Early Warning ◽  
Hydrodynamic Model ◽  
Coastal Area ◽  
East Coast ◽  
Coefficient Of Determination ◽  
Wind Effect ◽  
Coastal Inundation ◽  
Better Than

Abstract Coastal inundation has a great impact on the environment, such as damage to infrastructure and pollution of land and water. One of the efforts to prevent coastal inundation is to predict the water level. Delft3D is a hydrodynamic model that's able to simulate the water level. Coastal inundation research using the Delft3D model is still rarely done in Indonesia, especially on the east coast of Sumatra. This research is conducted in Belawan coastal area by simulating the water level that caused the coastal inundation using the Delft3D model. The best bathymetry for the prediction of water level and the magnitude of the wind effect was obtained from the simulation. The final step is to predict the water level in Belawan coastal area. The result of this research shows that the Delft3D model can simulate the water level which causes the coastal inundation in the Belawan coastal area. The correlation of the Delft3D model is 0.9, and the RMSE of GEBCO bathymetry is 0.39 meters and the RMSE of NOAA bathymetry is 0.46 meters. The GEBCO bathymetry is better than NOAA bathymetry in describing the water level in the Belawan coastal area. The wind effect on the water level simulations is not significant because the coefficient of determination is 0.47%. Besides, the Delft3D model with GEBCO bathymetry input can predict the water level which causes the coastal inundation with correlation reaches 0.92 and RMSE is 0.39 meters.

scholarly journals On the Quality of Real-Time Altimeter Gridded Fields: Comparison with In Situ Data

2009 ◽  
Vol 26 (3) ◽  
pp. 556-569 ◽  
Author(s):  
Ananda Pascual ◽  
Christine Boone ◽  
Gilles Larnicol ◽  
Pierre-Yves Le Traon
Keyword(s):  
Real Time ◽  
Sea Level ◽  
Tide Gauge ◽  
Deep Ocean ◽  
Velocity Estimation ◽  
Time Data ◽  
In Situ Data ◽  
Delayed Time

Abstract The timeliness of satellite altimeter measurements has a significant effect on their value for operational oceanography. In this paper, an Observing System Experiment (OSE) approach is used to assess the quality of real-time altimeter products, a key issue for robust monitoring and forecasting of the ocean state. In addition, the effect of two improved geophysical corrections and the number of missions that are combined in the altimeter products are also analyzed. The improved tidal and atmospheric corrections have a significant effect in coastal areas (0–100 km from the shore), and a comparison with tide gauge observations shows a slightly better agreement with the gridded delayed-time sea level anomalies (SLAs) with two altimeters [Jason-1 and European Remote Sensing Satellite-2 (ERS-2)/Envisat] using the new geophysical corrections (mean square differences in percent of tide gauge variance of 35.3%) than those with four missions [Jason-1, ERS/Envisat, Ocean Topography Experiment (TOPEX)/Poseidoninterlaced, and Geosat Follow-On] but using the old corrections (36.7%). In the deep ocean, however, the correction improvements have little influence. The performance of fast delivery products versus delayed-time data is compared using independent in situ data (tide gauge and drifter data). It clearly highlights the degradation of real-time SLA maps versus the delayed-time SLA maps: four altimeters are needed in real time to get the similar quality performance as two altimeters in delayed time (sea level error misfit around 36%, and zonal and meridional velocity estimation errors of 27% and 33%, respectively). This study proves that the continuous improvement of geophysical corrections is very important, and that it is essential to stay above a minimum threshold of four available altimetric missions to capture the main space and time oceanic scales in fast delivery products.

The Copernicus global 1/12° oceanic and sea ice reanalysis

2021 ◽  
Author(s):  
Jean-Michel Lellouche ◽  
Romain Bourdalle-Badie ◽  
Eric Greiner ◽  
Gilles Garric ◽  
Angelique Melet ◽  
...  
Keyword(s):  
Sea Ice ◽  
Real Time ◽  
Sea Level ◽  
Observation System ◽  
Small Scale ◽  
Free Access ◽  
In Situ Observation ◽  
Seasonal Forecasts ◽  
Concentration Data

<p>The GLORYS12V1 system is a global eddy-resolving physical ocean and sea ice reanalysis at 1/12° resolution covering the 1993-present altimetry period, designed and implemented in the framework of the Copernicus Marine Environment Monitoring Service (CMEMS). All the essential ocean physical variables from this reanalysis are available with free access through the CMEMS data portal.</p><p>The GLORYS12V1 reanalysis is based on the current CMEMS global real-time forecasting system, apart from a few specificities that are detailed in this manuscript. The model component is the NEMO platform driven at the surface by atmospheric conditions from the ECMWF ERA-Interim reanalysis. Ocean observations are assimilated by means of a reduced-order Kalman filter. Along track altimeter sea level anomaly, satellite sea surface temperature and sea ice concentration data and in situ temperature and salinity (T/S) vertical profiles are jointly assimilated. A 3D-VAR scheme provides an additional correction for the slowly-evolving large-scale biases in temperature and salinity.</p><p>The performance of the reanalysis is first addressed in the space of the assimilated observations and shows a clear dependency on the time-dependent in situ observation system, which is intrinsic to most reanalyses. The general assessment of GLORYS12V1 highlights a level of performance at the state-of-the-art and the reliability of the system to correctly capture the main expected climatic interannual variability signals for ocean and sea ice, the general circulation and the inter-basins exchanges. In terms of trends, GLORYS12V1 shows a higher than observed  warming trend together with a lower than observed global mean sea level rise.</p><p>Comparisons made with an experiment carried out on the same platform without assimilation show the benefit of data assimilation in controlling water masses properties and their low frequency variability. Examination of the deep signals below 2000 m depth shows that the reanalysis does not suffer from artificial signals even in the pre-Argo period.</p><p>Moreover, GLORYS12V1 represents particularly well the small-scale variability of surface dynamics and compares well with independent (non-assimilated) data. Comparisons made with a twin experiment carried out at ¼° resolution allows characterizing and quantifying the strengthened contribution of the 1/12° resolution onto the downscaled dynamics.</p><p>In conclusion, GLORYS12V1 provides a reliable physical ocean state for climate variability and supports applications such as seasonal forecasts. In addition, this reanalysis has strong assets to serve regional applications and should provide relevant physical conditions for applications such as marine biogeochemistry. In a near future, GLORYS12V1 will be maintained to be as close as possible to real time and could therefore provide a relevant reference statistical framework for many operational applications.</p>

scholarly journals ENSURF: multi-model sea level forecast – implementation and validation results for the IBIROOS and Western Mediterranean regions

Ocean Science ◽  
2012 ◽  
Vol 8 (2) ◽  
pp. 211-226 ◽  
Author(s):  
B. Pérez ◽  
R. Brouwer ◽  
J. Beckers ◽  
D. Paradis ◽  
C. Balseiro ◽  
...  
Keyword(s):  
Real Time ◽  
Sea Level ◽  
Bayesian Model ◽  
Weighted Average ◽  
Western Mediterranean ◽  
Bayesian Model Average ◽  
Easy Access ◽  
Visualization Tool ◽  
Average Technique ◽  
Model Average

Abstract. ENSURF (Ensemble SURge Forecast) is a multi-model application for sea level forecast that makes use of several storm surge or circulation models and near-real time tide gauge data in the region, with the following main goals: 1. providing easy access to existing forecasts, as well as to its performance and model validation, by means of an adequate visualization tool; 2. generation of better forecasts of sea level, including confidence intervals, by means of the Bayesian Model Average technique (BMA). The Bayesian Model Average technique generates an overall forecast probability density function (PDF) by making a weighted average of the individual forecasts PDF's; the weights represent the Bayesian likelihood that a model will give the correct forecast and are continuously updated based on the performance of the models during a recent training period. This implies the technique needs the availability of sea level data from tide gauges in near-real time. The system was implemented for the European Atlantic facade (IBIROOS region) and Western Mediterranean coast based on the MATROOS visualization tool developed by Deltares. Results of validation of the different models and BMA implementation for the main harbours are presented for these regions where this kind of activity is performed for the first time. The system is currently operational at Puertos del Estado and has proved to be useful in the detection of calibration problems in some of the circulation models, in the identification of the systematic differences between baroclinic and barotropic models for sea level forecasts and to demonstrate the feasibility of providing an overall probabilistic forecast, based on the BMA method.

GPRS based Real-Time Reporting and Internet Accessible Sea Level Gauge for Monitoring Storm Surge and Tsunami

2006 ◽  
Author(s):  
R.G. Prabhudesai ◽  
Antony Joseph ◽  
Yogesh Agarvadekar ◽  
Nitin Dabholkar ◽  
Prakash Mehra ◽  
...  
Keyword(s):  
Real Time ◽  
Sea Level ◽  
Storm Surge ◽  
Level Gauge
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