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1.
This study deals with the development of statistical modeling for water wave surface elevation by using a method that combines a dynamic solution with random process statistics. Ocean wave data taken from four NOAA (National Oceanic and Atmospheric Administration) buoys moored in the northeast Pacific were used to validate the model. The results indicated that the nonlinear probability density distribution of ocean wave surface elevation derived from the model described the measurements much better than Gaussian distribution and Longuet-Higgins distribution. 相似文献
2.
In the design of wind turbine foundations for offshore wind farms, the wave load and run-up slamming on the supporting structure are the quantities that need to be considered. Because of a special arc transition, the interaction between the wave field and the composite bucket foundation(CBF) becomes complicated. In this study, the hydrodynamic characteristics, including wave pressure, load, upwelling, and run-up, around the arc transition of a CBF influenced by regular waves are investigated through physical tests at Shandong Provincial Key Laboratory of Ocean Engineering, Ocean University of China. The distributions of the wave pressures and upwelling ratios around the CBF are described, and the relationship between the wave load and the wave parameters is discussed. New formulae based on the velocity stagnation head theory with linear wave theory and the second-order Stokes wave theory for wave kinematics are proposed to estimate the wave run-up. Moreover, the multiple regression method with nonlinear technology is employed to deduce an empirical formula for predicting run-up heights. Results show that the non-dimensional wave load increases with the increase in the values of the wave scattering parameter and relative wave height. The wave upwelling height is high in front of the CBF and has the lowest value at an angle of 135? with the incoming wave direction. The performance of the new formulae proposed in this study is compared using statistical indices to demonstrate that a good fit is obtained by the multiple regression method and the analytical model based on the velocity stagnation head theory is underdeveloped. 相似文献
3.
Significant wave height is an important criterion in designing coastal and offshore structures. Based on the orthogonality
principle, the linear mean square estimation method is applied to calculate significant wave height in this paper. Twenty-eight-year
time series of wave data collected from three ocean buoys near San Francisco along the California coast are analyzed. It is
proved theoretically that the computation error will be reduced by using as many measured data as possible for the calculation
of significant wave height. Measured significant wave height at one buoy location is compared with the calculated value based
on the data from two other adjacent buoys. The results indicate that the linear mean square estimation method can be well
applied to the calculation and prediction of significant wave height in coastal regions. 相似文献
4.
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????T/P(TOPEX/POSEIDON)????????????????????????????????????T/P?????????????????????????????????????????????????????????У??????С????????????????????????????????????????????????????Ч??????T/P?????Ч???????0.3m??????T/P????????Jason??1?????????????????????????????????????????????????????????????????????????????????????????????????????á?T/P??Jason??1????????????????Ч?????????????????????????0.21 m??0.05 m?? 相似文献
5.
Zheng Chongwei Liang Bingchen Chen Xuan Wu Guoxiang Sun Xiaofang Yao Jinglong 《中国海洋大学学报(英文版)》2020,19(3):479-488
Research on the diffusion characteristics of swells contributes positively to wave energy forecasting, swell monitoring, and early warning. In this work, the South Indian Ocean westerly index(SIWI) and Indian Ocean swell diffusion effect index(IOSDEI) are defined on the basis of the 45-year(September 1957–August 2002) ERA-40 wave reanalysis data from the European Centre for Medium-Range Weather Forecasts(ECMWF) to analyze the impact of the South Indian Ocean westerlies on the propagation of swell acreage. The following results were obtained: 1) The South Indian Ocean swell mainly propagates from southwest to northeast. The swell also spreads to the Arabian Sea upon reaching low-latitude waters. The 2.0-meter contour of the swell can reach northward to Sri Lankan waters. 2) The size of the IOSDEI is determined by the SIWI strength. The IOSDEI requires approximately 2–3.5 days to fully respond to the SIWI. The correlations between SIWI and IOSDEI show obvious seasonal differences, with the highest correlations found in December–January–February(DJF) and the lowest correlations observed in June–July–August(JJA). 3) The SIWI and IOSDEI have a common period of approximately 1 week in JJA and DJF. The SIWI leads by approximately 2–3 days in this common period. 相似文献
6.
《中国海洋湖沼学报》2016,(5)
Directional wave spectra and integrated wave parameters can be derived from X-band radar sea surface images.A vessel on the sea surface has a significant influence on wave parameter inversions that can be seen as intensive backscatter speckles in X-band wave monitoring radar sea surface images.A novel algorithm to eliminate the interference of vessels in ocean wave height inversions from X-band wave monitoring radar is proposed.This algorithm is based on the characteristics of the interference.The principal components(PCs) of a sea surface image sequence are extracted using empirical orthogonal function(EOF)analysis.The standard deviation of the PCs is then used to identify vessel interference within the image sequence.To mitigate the interference,a suppression method based on a frequency domain geometric model is applied.The algorithm framework has been applied to OSMAR-X,a wave monitoring system developed by Wuhan University,based on nautical X-band radar.Several sea surface images captured on vessels by OSMAR-X are processed using the method proposed in this paper.Inversion schemes are validated by comparisons with data from in situ wave buoys.The root-mean-square error between the significant wave heights(SWH) retrieved from original interference radar images and those measured by the buoy is reduced by 0.25 m.The determinations of surface gravity wave parameters,in particular SWH,confirm the applicability of the proposed method. 相似文献
7.
8.
The Antarctic circumpolar wave （ACW） has become a focus of the air-sea coupled Southern Ocean study since 1996, when it was discovered as an air-sea coupled interannual signal propagating eastward in the region of the Antarctic Circumpolar Current （ACC）. In order to analyze the mechanism of discontinuity along the latitudinal propagation, a new idea that ACW is a system with a traveling wave in the Southern Pacific and Atlantic Ocean and with a concurrent standing wave in the southern Indian Ocean is proposed in this paper. Based on the ideal wave principle, the average wave parameters of ACW is achieved using a non-linear approximation method, by which we find that the standing part and the traveling part possess similar radius frequency, proving their belonging to an integral system. We also give the latitudinal distribution of wave speed with which we could tell the reason for steady propagation during the same period. The spatial distribution of the propagation reveals complex process with variant spatial and temporal scales--The ENSO scale oscillation greatly impacts on the traveling process, while the result at the south of Australia indicates little connection between the Indian Ocean and the Pacific, which may be blocked by the vibration at the west of the Pacific. The advective effect of ACC on the propagation process should be examined clearly through dynamical method. 相似文献
9.
SHI Hongyuan CAO Xuefeng LI Qingjie LI Delei SUN Jiacheng YOU Zaijin SUN Qingying 《中国海洋大学学报(英文版)》2021,(1)
Wave parameters, such as wave height and wave period, are important for human activities, such as navigation, ocean engineering and sediment transport, etc. In this study, wave data from six buoys around Chinese waters, are used to assess the quality of wave height and wave period in the ERA5 reanalysis of the European Centre for Medium-Range Weather Forecasts. Annual hourly data with temporal resolution are used. The difference between the significant wave height(SWH) of ERA 5 and that of the buoy varies from-0.35 m to 0.30 m for the three shallow locations;for the three deep locations, the variation ranges from-0.09 m to 0.09 m. The ERA5 SWH data show positive biases, indicating an overall overestimation for all locations, except for E2 and S1 where underestimation is observed. During the tropical cyclone period, a large(about 32%) underestimation of the maximum SWH in the ERA5 data is observed. Hence, the ERA5 SWH data cannot be used for design applications without site-specific validation. The difference between the annual wave period from ERA5 and the mean wave period from the buoys varies from-1.31 s to 0.4 s. Inter-comparisons suggest that the ERA5 dataset is consistent with the annual mean SWH. However, for the average period, the performance is not good, and half of the correlation coefficients in the four points are less 50%. Overall, the deep water area simulation effect is better than that in the shallow water. 相似文献
10.
Hybrid tilapia were reared at densities of 1, 5 or 10 fish per tank for four weeks. Mortality was 0 at 1 and 10 fish per tank,
but was 25% at 5 fish per tank. Specific growth rate was highest at 1 fish per tank, and lowest at 5 fish per tank. The lower
growth rate at the intermediate stocking density was associated with reduced feed efficiency, but there was no reduction in
feed intake or digestibility. The results suggested increased metabolic cost caused by aggressive behaviour at intermediate
stocking density, which can be suppressed by a further increase in density.
This project was financially supported by the State Key Laboratory of Freshwater Ecology and Biotechnology of China and by
Shanghai Fisheries University (Project SFU. 200003). 相似文献
11.
A new ocean wave and sea surface current monitoring system with horizontally-(HH) and vertically-(VV) polarized X-band radar
was developed. Two experiments into the use of the radar system were carried out at two sites, respectively, for calibration
process in Zhangzi Island of the Yellow Sea, and for validation in the Yellow Sea and South China Sea. Ocean wave parameters
and sea surface current velocities were retrieved from the dual polarized radar image sequences based on an inverse method.
The results obtained from dual-polarized radar data sets acquired in Zhangzi Island are compared with those from an ocean
directional buoy. The results show that ocean wave parameters and sea surface current velocities retrieved from radar image
sets are in a good agreement with those observed by the buoy. In particular, it has been found that the vertically-polarized
radar is better than the horizontally-polarized radar in retrieving ocean wave parameters, especially in detecting the significant
wave height below 1.0 m. 相似文献
12.
lareODUcrI0NThephenomenonofbreakingwavesintheoasnoocurswheneveramomentahiyhighcrestmecheSanunstablecondition.It0ccursintendtimhy,andtheoccurrencefre-qUencydePendsonthescastate.ManystudAshaddricaniedoutontheoccurmcefre-qUencyofbrmkingwavesindeepweter.0chiandTsai(l983),LongueHiggins(l975)andVanD0mandPamn(l975)nadstheptalictonofbrmkingwavesoccurrenceindeePwater,usingabaskingcriterionforindividualwavesbasedonthewavesmpness.ThecriterioncanbeexpmeedintennSofthewaVehdghtHandperiodTasH>PgT'(… 相似文献
13.
周静 《广东海洋大学学报》2009,29(5):31-33
2009年7月20日至21日,由广东社会学学会海洋专业委员会发起,广东海洋大学和中国海洋大学联合主办了"中国海洋社会变迁与海洋社会学学科建设学术研讨会"。会议围绕海洋社会学学科建设与深入海洋社会研究的两大主题展开交流与讨论,展现我国社会学学者的海洋关怀与主张,展望了基于田野灵感的经验分析和理论建构的海洋社会学学科研究的操作途径和发展前景。 相似文献
14.
In this study, the simulating waves nearshore(SWAN) model with a locally refined curvilinear grid system was constructed to simulate waves in Jervis Bay and the neighbouring ocean of Australia, with the aim of examining the wave characteristics in an area with special topography and practical importance.This model was verified by field observations from buoys and acoustic Doppler profilers(ADPs). The model precisions were validated for both wind-generated waves and open-ocean swells. We present an approach with which to convert ADP-observed current data from near the bottom into the significant wave height. Our approach is deduced from the Fourier transform technique and the linear wave theory. The results illustrate that the location of the bay entrance is important because it allows the swells in the dominant direction to propagate into the bay despite the narrowness of the bay entrance. The wave period T p is also strongly related to the wave direction in the semi-enclosed bay. The T p is great enough along the entire propagating direction from the bay entrance to the top of the bay, and the largest T p appears along the north-west coast,which is the end tip of the swells' propagation. 相似文献
15.
Storm surge inundation is a major concern in marine hazard risk assessment during extreme weather conditions.In this study,a high-resolution coupled model(the ADVanced CIRCulation model+the Simulating WAves Nearshore model)was used to investigate the storm surge inundation in the southwestern Hangzhou Bay region during Typhoon Chan-hom in 2015.The simulated hydrodynamic processes(sea surface wave and storm tide)were validated with measured data from wave buoys and tide gauges,indicating that the overall performance of the model was satisfactory.The storm surge inundation in the coastal area was simulated for several idealized control experiments,including different wave effects(wave-enhanced wind stress,wave-enhanced bottom stress,and wave radiation stress).Dike overflowing cases with different dike heights and dike breaking cases with different dike breach lengths were considered in the simulation.The results highlight the necessity of incorporating wave effects in the accurate simulation of storm surge inundation.Dike height significantly influences the magnitude and phase of the maximum inundation area in the dike overflowing cases,and dike breach length is an important factor impacting the magnitude of the maximum inundation area in the dike breaking cases.This study may serve as a useful reference for accurate coastal inundation simulation and risk assessment. 相似文献
16.
《中国海洋湖沼学报》2020,(4)
The equatorial wave dynamics of interannual sea level variations between 2014/2015 and2015/2016 El Nino events are compared using the Laboratory of Numerical Modeling for Atmospheric Sciences and Geophysical Fluid Dynamics,Institute of Atmospheric Physics Climate Ocean Model(LICOM) forced by the National Centers for Environmental Prediction(NCEP) reanalysis I wind stre s s and heat flux during 2000-2015.In addition,the LICOM can reproduce the interannual variability of sea surface temperature anomalies(SSTA) and sea level anomalies(SLA) along the equator over the Pacific Ocean in comparison with the Hadley center and altimetric data well.We extracted the equatorial wave coefficients of LICOM simulation to get the contribution to SLA by multiplying the meridional wave structure.During 2014/2015 El Nino event,upwelling equatorial Kelvin waves from the western boundary in April2014 reach the eastern Pacific Ocean,which weakened SLA in the eastern Pacific Ocean.However,no upwelling equatorial Kelvin waves from the western boundary of the Pacific Ocean could reach the eastern boundary during the 2015/2016 El Nino event.Linear wave model results also demonstrate that upwelling equatorial Kelvin waves in both 2014/2015 and 2015/2016 from the western boundary can reach the eastern boundary.However,the contribution from stronger westerly anomalies forced downwelling equatorial Kelvin waves overwhelmed that from the upwelling equatorial Kelvin waves from the western boundary in 2015.Therefore,the western boundary reflection and weak westerly wind burst inhibited the growth of the 2014/2015 El Nino event.The disclosed equatorial wave dynamics are important to the simulation and prediction of ENSO events in future studies. 相似文献
17.
Whitecapping plays an important role in many air-sea exchange and upper ocean processes. Traditionally, whitecap coverage
is parameterized as a function of wind speed only. At present, the relative speed of ocean current to wind is considered to
be important in the air-sea exchange parameterization which is the function of wind speed only. In this paper, the effects
of ocean surface velocity (current velocity and wave induced velocity) and the wave parameters on whitecap coverage through
relative speeds are investigated, by applying a 2-parameter whitecap coverage model to the Atlantic Ocean. It is found that
the impacts of both current and wave on whitecap coverage are considerable in the most part of the Atlantic Ocean. It is interesting
that the effect of wave is more significant than that of current. 相似文献
18.
Yongcun Cheng Qing Xu Yuguang Liu Chongyin Li Zengzui Rong Haibo Zong Xiu Peng Xiaobin Yin 《中国海洋大学学报(英文版)》2008,7(4):379-384
Time series of sea surface temperature (SST),wind speed and significant wave height (SWH) from meteorologicalbuoys of the National Data Buoy Center (NDBC) are useful for studying the interannual variability and trend of these quantities at the buoy areas.The measurements from 4 buoys (B51001,B51002,B51003 and B51004) in the Hawaii area are used to study theresponses of the quantities to EI Nino and Southern Oscillation (ENSO).Long-term averages of these data reflect precise seasonaland climatological characteristics of SST,wind speed and SWH around the Hawaii area.Buoy observations from B51001 suggest asignificant warming trend which is,however,not very clear from the other three buoys.Compared with the variability of SST andSWH,the wind speeds from the buoy observations show an increasing trend.The impacts of El Nifio on SST and wind waves arealso shown.Sea level data observed by altimeter during October 1992 to September 2006 are analyzed to investigate the variabilityof sea level in the Hawaii area.The results also show an increasing trend in sea level anomaly (SLA).The low-passed SLA in theHawaii area is consistent with the inverse phase of the low-passed Sol (Southern Oscillation Index).Compared with the low-passedSOl and PDO (Pacific Decadal Oscillation),the low-passed PNA (Pacific-North America Index) has a better correlation with thelow-passed SLA in the Hawaii area. 相似文献
19.
The existence of three well-defined tongue-shaped zones of swell dominance, termed as ‘swell pools’, in the Pacific, the Atlantic
and the Indian Oceans, was reported by Chen et al. (2002) using satellite data. In this paper, the ECMWF Re-analyses wind wave data, including wind speed, significant wave
height, averaged wave period and direction, are applied to verify the existence of these swell pools. The swell indices calculated
from wave height, wave age and correlation coefficient are used to identify swell events. The wave age swell index can be
more appropriately related to physical processes compared to the other two swell indices. Based on the ECMWF data the swell
pools in the Pacific and the Atlantic Oceans are confirmed, but the expected swell pool in the Indian Ocean is not pronounced.
The seasonal variations of global and hemispherical swell indices are investigated, and the argument that swells in the pools
seemed to originate mostly from the winter hemisphere is supported by the seasonal variation of the averaged wave direction.
The northward bending of the swell pools in the Pacific and the Atlantic Oceans in summer is not revealed by the ECMWF data.
The swell pool in the Indian Ocean and the summer northward bending of the swell pools in the Pacific and the Atlantic Oceans
need to be further verified by other datasets. 相似文献
20.
The seawater complexation capacity for heavy metals (copper, lead and cadmium) in the South China Sea was determined by anodic
voltammetry and the conditional stability constants of these complexes were calculated. The data showed that the complexation
capacity of the South China Sea water was greater than that of seawater in the Huanghe Estuary and the coast water of Qingdao.
The sequence of complexation capacity is C (CuL)>C(PbL)>C(CdL), and the conditional stability constants were in an opposite
sequence: K(CuL)<K(PbL)<K(CdL).
The types, and shapes of the complexation capacity profiles for Cu, Cd and Pb were similar to those obtained by Buckley (1986)
for the Atlantic Ocean water. Complexation capacity is maximum at the surface layer, decreasing with depth, reaching minimum
at 750m, but increasing again near the sea bottom.
This project was supported by a grant from the State Educational Commission for subsidizing excellent young teachers and a
grant from the National Science Foundation Commission of China.
Guo Boshu is a visiting scholar from Inner Mongolia Normal University at Huho Haote. This paper is part of her work at Ocean
University of Qingdao. 相似文献