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1.
A new database of ocean wave parameters has been created based on satellite altimetry observations. The basis was data from the European Space Agency project GlobWave (www.globwave.org), which was transformed to suit upcoming requirements for global wave analysis. The new database contains additional wave characteristics (altimetry wind speed estimated using different parametric models, steepness, period, and some quality control parameters). It provides up-to-date tools for mass data preprocessing. The new database makes it possible to optimize wave field diagnostics on regional and global scales. Using the Envisat and Jason-1 satellite missions as an the example, we demonstrate the specific features of using the initial GlobalWave data set and the modified database. 相似文献
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Characteristics of abnormal waves in North Sea storm sea states 总被引：1，自引：0，他引：1
A data set of storm wave records from the North Sea is analysed. Using current definitions of abnormal waves, eight of the largest wind waves are defined as abnormal waves. Twenty-four of the largest waves in time series, with a height larger than 10 m and with big vertical asymmetry are chosen for further analysis. Their individual characteristics are investigated and related to the global sea state characteristics. A comparison between measured data, second-order theory predictions and offshore basin data is made. The results for the chosen waves do not coincide with predictions of second-order theory. Considering that wind wave is second- and third-order non-linear, a new relationship between skewness and kurtosis is proposed for the sea states in which extremely asymmetric large waves have occurred. Another relationship between kurtosis and abnormality index of maximum waves is proposed too. 相似文献
3.
世界大洋长历时局地风速和有效波高的统计与分析 总被引：1，自引：0，他引：1
本文基于美国海军测地卫星高度计提供的全球范围长历时局地平均风速和有效波高资料进行统计分析,结果表明,世界大洋长历时局地平均风速和有效波高有明显的相关性,其散布点系统地位于Wilson提出的深水充分成长风浪平均风速和有效波高经验曲线之上;并从能量叠加平衡方程,近似定量估计出大洋中长历时涌浪有效波高与局地平均风速的关系。 相似文献
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本文应用一个经验证的全球尺度FVCOM海浪模型，模拟了2012年全球海洋海浪场的分布和演变，分析了海表面风场、海浪场与混合层深度的全球尺度分布及相关性。综合观测资料和模型结果显示，海表面10 m风速、有效波高与混合层深度的全球尺度分布随季节发生显著的变化，并且其分布态势存在明显的相似性。从相关系数的全球分布来看，海表面10 m风速在印度洋低纬度海区（纬度0°~20°）与混合层深度间有较强的相关性，相关系数大于0.5；有效波高与混合层深度间相关系数大于0.5的网格分布在北半球高纬度海区和印度洋北部。谱峰周期与混合层深度间在部分海区存在负相关关系，这些网格主要分布在低纬度海区（纬度0°~30°）。统计结果显示，有效波高、海表面10 m风速和谱峰周期与混合层深度间的平均相关系数分别为0.31、0.25和0.12。综合以上结果表明，有效波高较谱峰周期能更有效地表征波浪能对海洋上层混合的影响；相比于海表面风速，有效波高与混合层深度间存在更强的相关关系，其变化对海洋上层混合有更显著的影响。 相似文献
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卫星高度计实现了对全球性或区域性的海洋参量的实时监测,TOPEX卫星高度计提供了迄今为止时间序列最长、数据质量最高的全球海面风速和有效波高的同步观测资料。利用TOPEX卫星高度计资料,分析了有效波高4m以上的巨浪在台湾岛周边海域的时空分布特征,结果表明台湾岛周边海域巨浪的分布具有明显的季节特征。每年平均有效波高最大值大多数出现在夏季,春季是1a中有效波高最小的季节,而秋季和冬季是巨浪出现频率最高的季节。波高大于6m的巨浪大都出现在台湾岛东部及东北部海域,在南部海域出现较少。 相似文献
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《海洋技术学报》2023,(2)
本文基于唐山近海海域1#、2#浮标2017年4月至11 月实时海浪观测数据及部分风速风向数据, 对唐山近海海域波浪有效波高、有效波向、有效波周期等波参数特征进行了统计分析, 并利用origin 软件对波参数与风速、风向相关性进行了研究。研究结果表明： 1#、2# 浮标海域常浪向为SSW、SW、SSE, 常浪向有效波高均以0.2 ～ 0.4 m 小浪及3 ～ 4 s 短周期为主,有效波高1 m 以上较大波浪极少出现; 该海域波浪以风浪为主, 波浪破碎速度较快, 有效波高与风速相关性较强, 相关系数r 为0.71, 风向与波向、有效波高与周期基本无相关性, 该研究资料可为海上活动及防灾减灾提供技术依据。 相似文献
7.
Measurements from the GEOSAT, ERS-1 and 2 and Topex/Poseidon satellites have now accumulated to over 15 years of global ocean wave and wind data. Extraction of wave height, wind speed and wave period from the satellite altimeters and directional wave spectra from the synthetic aperture radars are reviewed along with recent validation and calibration efforts. Applications of the data to a variety of problems illustrate the potential of satellite wave measurements. 相似文献
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PL Woodworth 《African Journal of Marine Science》2020,42(2):233-245
Wave setup was investigated using data from tide gauges in a small harbour at the island of Tristan da Cunha in the South Atlantic Ocean. Frequent examples of wave setup were found during the period 1986–1992, but were much less apparent after 1992, following extensions to the two breakwater arms of the harbour. The unambiguous association of wave setup with the several-decimetre spikes in Tristan sea level, which can persist for a day or so, are a warning that signals related to wave setup could also occur in other tide gauge records, where the wave setup signal could perhaps be misinterpreted as wind setup within the overall storm surge. One conclusion is that, in spite of the difficulties of access to Tristan da Cunha and its ever-present hostile wave climate, the island is undoubtedly now worthy of a permanent tide-gauge installation, which would be an important contribution to the global sea-level network. 相似文献
11.
I. R. Young 《Ocean Engineering》1999,26(1):67
Mean monthly values of altimeter wind speed and wave height are compared with data from NDBC buoys. As a result of these comparisons, corrections are made to the raw data products available from these satellites. Data from the GEOSAT, TOPEX and ERS1 missions corrected in this fashion are used to show that there have been no measurable changes in the global wind and wave climate during the 10 years spanned by these various missions. It is proposed that the corrected values of wind speed and wave height provide the basis for the formation of a long-term global data base which spans the periods of these multiple missions. 相似文献
12.
The comparison of altimeter retrieval algorithms of the wind speed and the wave period 总被引：3，自引：3，他引：0
With the launch of altimeter,much effort has been made to develop algorithms on the wind speed and the wave period.By using a large data set of collocated altimeter and buoy measurements,the typical wind speed and wave period algorithms are validated.Based on theoretical argument and the concept of wave age,a semi-empirical algorithm for the wave period is also proposed,which has the wave-period dimension,and explicitly demonstrates the relationships between the wave period and the other variables.It is found that Ku and C band data should be applied simultaneously in order to improve either wind speed or wave period algorithms.The dual-band algorithms proposed by Chen et al.(2002) for the wind speed and Quilfen et al.(2004) for the wave period perform best in terms of a root mean square error in the practical applications. 相似文献
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Global sea surface wind field data derived from NCEP reanalysis were used in driving a SWAN wave model to reconstruct historical wave records from 1948 to 2008. The reconstructed wave data were compared and verified by the observation of the data buoys of the Central Weather Bureau and the Water Resources Agency, Taiwan, and the National Data Buoy Center/National Oceanic and Atmospheric Administration, United States. Over the past six decades, the wave climate in Taiwan waters has undergone considerable changes. The annual mean significant wave heights have reduced an average of 0.31 cm/year. Winter wave heights have gradually dropped 0.86 cm/year, which are related to the weakening of winter monsoons. Regarding the inter-annual wave climate variation, the influence of El Niño/southern oscillation was substantial; the wave heights increased in La Niña years and decreased in El Niño years. In the past 60 years, extreme wave events have been concentrated in two periods: 1967–1974 and 2000–2008. More severe extreme wave events occurred in the latter compared with the former, and all were induced by typhoons. A clear trend, in which the summer (winter) extreme wave events have increased (decreased) gradually, has been identified. The 1980s was the transition period. After the transition period, the annual occurrence of extreme wave events caused by typhoons exceeded those caused by an intense outbreak of winter cold surges, although the total number of the annual extreme wave events has not changed substantially. 相似文献
15.
Long term wave climate of both extreme wave and operational wave height is essential for planning and designing coastal structures.
Since the field wave data for the waters around Korean peninsula is not enough to provide reliable wave statistics, the wave
climate information has been generated by means of long-term wave hindcasting using available meteorological data. Basic data
base of hindcasted wave parameters such as significant wave height, peak period and direction has been established continuously
for the period of 25 years starting from 1979 and for major 106 typhoons for the past 53 years since 1951 for each grid point
of the North East Asia Regional Seas with grid size of 18 km. Wind field reanalyzed by European Center for Midrange Weather
Forecasts (ECMWF) was used for the simulation of waves for the extratropical storms, while wind field calculated by typhoon
wind model with typhoon parameters carefully analyzed using most of the available data was used for the simulation of typhoon
waves. Design wave heights for the return period of 10, 20, 30, 50 and 100 years for 16 directions at each grid point have
been estimated by means of extreme wave analysis using the wave simulation data. As in conventional methodsi of design criteria
estimation, it is assumed that the climate is stationary and the statistics and extreme analysis using the long-term hindcasting
data are used in the statistical prediction for the future. The method of extreme statistical analysis in handling the extreme
events like typhoon Maemi in 2003 was evaluated for more stable results of design wave height estimation for the return periods
of 30–50 years for the cost effective construction of coastal structures. 相似文献
16.
The impact of climate change on design wind speeds corresponding to different return periods at two selected offshore locations in India has been assessed. Extreme daily wind speeds corresponding to various return periods were derived based on the observations made by wave rider buoys during the period 1998–2005. Thereafter, the future climate over the next century was simulated at these locations using the input from the climate model: GCM-CGCM3 corresponding to the A2 scenario. The underlying downscaling model was developed with the help of artificial neural networks and using observed wind as output. The local wind speeds corresponding to these projected wind data were generated for the next century and return period wind speeds were extracted by the distribution fitting. Comparison of design wind speeds derived with and without consideration of future climate showed that the magnitude of the long term wind speed would certainly and significantly increases if the effect of global climate change is incorporated in the analysis. For the two locations considered, the increase in the 100-year wind was found to be varying from 44% to 74%. 相似文献
17.
台风引起的海浪灾害对我国黄、渤海沿岸影响巨大,严重威胁相关区域人民群众生命财产安全。本文主要利用ERA5(the fifth generation European Center for Medium-Range Weather forecasts atmospheric reanalysis of the global climate)风场研究了两类不同移动路径下的台风(1909号台风“利奇马”和1109号台风“梅花”)在黄、渤海区域的海浪场的时空分布特征及风-浪成长关系。结果表明:两个台风引起的海浪的有效波高空间分布明显不同,波高的分布和风速对应,而海浪周期与风速、波高的分布无明显相关性,波向较风向偏于台风移动方向且两者偏差较大;两个台风进入黄海之前就形成一个从黄海向渤海的“涌浪舌”。海浪成分方面,台风“利奇马”引起的沿海区大浪主要是风浪,而台风“梅花”移动路径的右侧以风浪为主,左侧则主要是涌浪;通过建立无因次波高与无因次周期的幂律关系、以及有效波高关于风速的二次多项式变化关系,研究了风-浪成长特性,结果发现,台风浪的成长特性与台风过程关系不明显,但与所处水域的水深和海底地形地貌有关,表现为两个台风在黄海区域的台风浪成长较渤海区域更为充分。 相似文献
18.
概念性地设计了一种新型半潜式海上风力机基础,确定了结构的型式和尺寸,对风浪联合作用下不同工况的风力机基础稳性进行了校核.考虑黏性阻尼和二阶波浪力的作用,计算分析了风力机基础的水动力系数、幅频运动以及动力响应特性.结果表明,经过改进的新型风力机基础具有良好的稳性和水动力性能,特别是在垂荡性能上有大幅的提升.波浪入射角度对垂荡的影响不大,但对其他自由度RAOs影响较大.垂荡、横摇和纵摇RAOs均存在一个主峰值和次峰值,但峰值周期均远离波能集中区.此外还发现,不同工况下风浪入射角对风机系统的动力响应和系泊力均有较大影响,相对于工作工况,极端工况下所受风荷载较小,但是系泊力更大. 相似文献
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This paper is aimed at the whole Bohai Sea,as the complement and improvement of wave characteristics and extreme parameters.Wave fields were simulated in the Bohai Sea by using wave model SWAN from 1985 to 2004.The input data based on the hindcast of high-resolution wind fields from RAMS and water level fields from POM,which have been tested and verified well.Comparisons of significant wave heights between simulation and station observations show a good agreement in general.By statistical analysis,the wave characteristics such as significant wave heights, dominant wave directions and their seasonal variations are discussed.In addition,main wave extreme parameters and directional extreme values particularly for 100-year return period are investigated. 相似文献