Global validation of the wave model WAM over a one-year period using Geosat wave height data

1993 ◽  
Vol 98 (C3) ◽  
pp. 4713-4726 ◽  
Author(s):  
Roland Romeiser
Keyword(s):  
Wave Height ◽  
Wave Model ◽  
One Year ◽  
Height Data

scholarly journals THỬ NGHIỆM ĐỒNG HOÁ SỐ LIỆU ĐỘ CAO SÓNG TRONG KHU VỰC BIỂN ĐÔNG BẰNG PHƯƠNG PHÁP LỌC KALMAN TỔ HỢP

2019 ◽  
Vol 18 (4) ◽  
pp. 358-367
Author(s):  
Nguyen Trung Thanh ◽  
Nguyen Minh Huan ◽  
Tran Quang Tien
Keyword(s):  
Probability Theory ◽  
Kalman Filter ◽  
Data Assimilation ◽  
Wave Height ◽  
Ensemble Kalman Filter ◽  
Wave Model ◽  
The Past ◽  
Ocean Data Assimilation ◽  
The World ◽  
Height Data

Advances in ocean data assimilation have been improved with the power of computers over the past 30 years, but the theory of data assimilation has a long history with the probability, theory of mathematical simulation, and traditional numerical calculations. Therefore, the research and application of data assimilation technology in oceanography have been widely carried out in the world and have gotten considerable achievements. In Vietnam, the study of data assimilation has also been applied in the meteorology and has attracted the increasing interest in oceanography. This paper presents the results of the study to calculate the wave height data from satellites combined with measured wave height data at MSP1 station of Vietsovpetro using the Ensemble Kalman Filter (EnKF) method associated with SWAN wave model in the Eastern Vietnam Sea.

scholarly journals The Condition of Significant Wave Height and Wind Velocity in Makassar Strait during 2017

2019 ◽  
Vol 3 (1) ◽  
pp. 179-189
Author(s):  
Hanah Khoirunnisa ◽  
Shofia Karima
Keyword(s):  
Energy Spectrum ◽  
Wind Velocity ◽  
Wave Height ◽  
Significant Wave Height ◽  
Secondary Data ◽  
Weather Forecasts ◽  
Significant Wave ◽  
A Value ◽  
One Year ◽  
Height Data

This study aims to look at the conditions and characteristics of significant wave height and its relationship to wind velocity in the Makassar Strait in 2017. The data used in this study are bathymetry data from GEBCO with a resolution of 30 seconds, significant wave height data (Hs) with a resolution of 0.25 x 0.25 as well as wind velocity and direction with a resolution of 0.25 x 0.25 which are secondary data results from the European Center for Medium-Range Weather Forecasts (ECMWF) with a span of one year in 2017. The method used in this research is an analysis of the energy spectrum of significant wave height using Fast Fourier Transform. In addition, wind velocity and direction are processed by using GrADS software to see the visual conditions. Based on this study, it can be concluded that wind velocity is strongly associated with significant wave height values. This can be seen at each sample point in the Makassar Strait, where when the value of wind velocity is high, the value of significant wave height has the same conditions, and vice versa. The wind velocity value has a maximum value in the Makassar Strait during the east season with a value of more than 4.5 m/s. The highest energy spectrum occurs at point 3 in the Makassar Strait, which is 7303 m2 with a period of 6 months.

scholarly journals Operational numerical wind-wave model for the Black Sea

2000 ◽  
Vol 1 (1) ◽  
pp. 65
Author(s):  
A. KORTCHEVA ◽  
G. KORTCHEV ◽  
J. M. LEFEVRE
Keyword(s):  
Shallow Water ◽  
Real Time ◽  
Wave Height ◽  
Black Sea ◽  
Water Wave ◽  
Wind Wave ◽  
Wave Model ◽  
The Black Sea ◽  
Sea State ◽  
Height Data

In this paper the discrete spectral shallow water wave model named VAGBUHL1 is presented. This model is used for real-time Black Sea state forecasting. The model was verified against satellite ERS-2 altimeter wave height data.

Error Estimation of Buoy, Satellite, and Model Wave Height Data

2007 ◽  
Vol 24 (9) ◽  
pp. 1665-1677 ◽  
Author(s):  
Peter A. E. M. Janssen ◽  
Saleh Abdalla ◽  
Hans Hersbach ◽  
Jean-Raymond Bidlot
Keyword(s):  
Collocation Method ◽  
Wave Height ◽  
Wave Model ◽  
Weather Forecasts ◽  
Model Wave ◽  
Analysis Scheme ◽  
Wave Heights ◽  
Forecasting System ◽  
Buoy Data ◽  
Height Data

Abstract Triple collocation is a powerful method to estimate the rms error in each of three collocated datasets, provided the errors are not correlated. Wave height analyses from the operational European Centre for Medium-Range Weather Forecasts (ECMWF) wave forecasting system over a 4-yr period are compared with independent buoy data and dependent European Remote Sensing Satellite-2 (ERS-2) altimeter wave height data, which have been used in the wave analysis. To apply the triple-collocation method, a fourth, independent dataset is obtained from a wave model hindcast without assimilation of altimeter wave observations. The seasonal dependence of the respective errors is discussed and, while in agreement with the properties of the analysis scheme, the wave height analysis is found to have the smallest error. In this comparison the altimeter wave height data have been obtained from an average over N individual observations. By comparing model wave height with the altimeter superobservations for different values of N, alternative estimates of altimeter and model error are obtained. There is only agreement with the estimates from the triple collocation when the correlation between individual altimeter observations is taken into account. The collocation method is also applied to estimate the error in Environmental Satellite (ENVISAT), ERS-2 altimeter, buoy, model first-guess, and analyzed wave heights. It is shown that there is a high correlation between ENVISAT and ERS-2 wave height error, while the quality of ENVISAT altimeter wave height is high.

A Method to Implement the Random Signals for Time Varying Offshore Wave Height During Storm Condition in an Intra-Wave Period Wave Model

2006 ◽  
Author(s):  
Yuliang Zhu ◽  
Shunqi Pan ◽  
Premanandan T. Fernando ◽  
Xiaoyan Zhou
Keyword(s):  
Wave Height ◽  
Wave Model ◽  
Peak Frequency ◽  
Wave Period ◽  
Storm Event ◽  
Time Varying ◽  
Wave Heights ◽  
Offshore Wave ◽  
Storm Condition ◽  
Period Wave

In this paper, a method to implement the surface elevation at the offshore boundary during storm conditions is presented in the intra-wave period wave model. At storm condition, the offshore incident significant wave height is time varying. In the case of time varying incident wave height, the JONSWAP energy spectrum can be manipulated as follows: H1/32s(f). s(f) is the energy density function for a unit wave height. During a storm event not only the offshore boundary significant wave heights but also the peak frequency varies. If we choose a mean peak frequency during a storm event, s(f) can be calculated for the mean peak frequency for the storm event. The amplitudes of the component waves for the random signals are calculated from the unit energy density function s(f), and the phase angle of the component wave, So we can numerically generate surface elevation time series for the time varying offshore wave heights. The method was verified in the intra-wave period wave model using field measurements at Sea Palling site Norfolk UK.

scholarly journals Evaluating skill of BMKG wave model forecast (Wavewatch-3) with observation data in Indian Ocean (5 – 31 December 2017).

2021 ◽  
Vol 893 (1) ◽  
pp. 012058
Author(s):  
R Kurniawan ◽  
H Harsa ◽  
A Ramdhani ◽  
W Fitria ◽  
D Rahmawati ◽  
...  
Keyword(s):  
Indian Ocean ◽  
Wave Height ◽  
Model Performance ◽  
Forecast Accuracy ◽  
Wave Model ◽  
Ocean Waves ◽  
Observation Data ◽  
Operating Characteristics ◽  
Wave Forecast ◽  
Good For

Abstract Providing Maritime meteorological forecasts (including ocean wave information) is one of BMKG duties. Currently, BMKG employs Wavewatch-3 (WW3) model to forecast ocean waves in Indonesia. Evaluating the wave forecasts is very important to improve the forecasts skill. This paper presents the evaluation of 7-days ahead BMKG’s wave forecast. The evaluation was performed by comparing wave data observation and BMKG wave forecast. The observation data were obtained from RV Mirai 1708 cruise on December 5th to 31st 2017 at the Indian Ocean around 04°14'S and 101°31'E. Some statistical properties and Relative Operating Characteristics (ROC) curve were utilized to assess the model performance. The evaluation processes were carried out on model’s parameters: Significant Wave Height (Hs) and Wind surface for each 7-days forecast started from 00 UTC. The comparation results show that, in average, WW3 forecasts are over-estimate the wave height than that of the observation. The forecast skills determined from the correlation and ROC curves are good for the first- and second-day forecast, while the third until seventh day decrease to fair. This phenomenon is suspected to be caused by the wind data characteristics provided by the Global Forecasts System (GFS) as the input of the model. Nevertheless, although statistical correlation is good for up to 2 days forecast, the average value of Root Mean Square Error (RMSE), absolute bias, and relative error are high. In general, this verifies the overestimate results of the model output and should be taken into consideration to improve BMKG’s wave model performance and forecast accuracy.

Effect of Uni- and Bi-Directional Coupling of Ocean-Met Interaction on Significant Wave Height and Local Wind

2017 ◽  
Author(s):  
Adil Rasheed ◽  
Jakob Kristoffer Süld ◽  
Mandar Tabib
Keyword(s):  
Wave Height ◽  
Significant Wave Height ◽  
Surface Wind ◽  
Wave Model ◽  
Ocean Surface ◽  
Observation Data ◽  
Local Wind ◽  
Near Surface ◽  
Significant Wave ◽  
Bidirectional Coupling

Accurate prediction of near surface wind and wave height are important for many offshore activities like fishing, boating, surfing, installation and maintenance of marine structures. The current work investigates the use of different methodologies to make accurate predictions of significant wave height and local wind. The methodology consists of coupling an atmospheric code HARMONIE and a wave model WAM. Two different kinds of coupling methodologies: unidirectional and bidirectional coupling are tested. While in Unidirectional coupling only the effects of atmosphere on ocean surface are taken into account, in bidirectional coupling the effects of ocean surface on the atmosphere are also accounted for. The predicted values of wave height and local wind at 10m above the ocean surface using both the methodologies are compared against observation data. The results show that during windy conditions, a bidirectional coupling methodology has better prediction capability.

scholarly journals Food intolerances and associated symptoms in patients undergoing Fobi-Capella technique without gastric ring

2015 ◽  
Vol 28 (1) ◽  
pp. 36-39 ◽  
Author(s):  
Marcella de Arruda MOREIRA ◽  
Patrícia Ramos Maciel ESPÍNOLA ◽  
Camila Wanderley de AZEVEDO ◽  
Cinthia Karla Rodrigues do Monte GUEDES
Keyword(s):  
Clinical Manifestations ◽  
Cross Sectional Study ◽  
Food Intolerance ◽  
World Health ◽  
Cross Sectional ◽  
Significant Difference ◽  
One Year ◽  
Health Organization ◽  
Nutritional Monitoring ◽  
Height Data

BACKGROUND: Bariatric surgery is considered the only effective method to treat refractory obesity, and especially for those in which clinical treatment was not successful. However, the appearance of food intolerances and clinical manifestations are quite common. AIM: To identify food intolerances and associated them to symptoms in patients undergoing Fobi-Capella technique without gastric ring. METHODS: This was a cross-sectional study of adult patients who had more than one year after surgery. Demographic, anthropometric, weight and preoperative height data were investigated. Nutritional status was classified according to the criteria established by the World Health Organization. It was considered food intolerance the presence of nausea, vomiting, diarrhea or bloating after eating a particular food. RESULTS: The sample consisted of 61 patients who attended the nutritional consultation of which 26 (42.6%) had food intolerance, mostly related to red meat (n=12; 34.3%) during the first six months of operation; there was a significant difference between the periods between 0 and 6 months, and 7 to 12 (p=0.02). Among the symptoms reported by patients, nausea was the most recurrent until the 6th month, but without significant differences between the two periods (p=0.06). CONCLUSION: The Fobi-Capella procedure without gastric ring promoted high frequency of intolerance to meat in general, especially for the red, chicken and fish, on this sequence; nausea was the most frequent symptom. These data suggest the need for adequate nutritional monitoring throughout the postoperative period.

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