共查询到19条相似文献，搜索用时 143 毫秒
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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4 m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1 a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6 m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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利用有效波高和风速的3种概率密度函数分布:Rayleigh概率密度函数分布、Weibull概率密度函数分布、Log-Normal密度函数分布,结合TOPEX卫星高度计资料,对台湾岛周边海域的有效波高和风速进行分析比较.结果表明:有效波高的观测资料直方图与Log-Normal概率密度函数分布符合较好;而风速的观测资料直方图与Weibull概率密度函数分布符合较好.台湾岛周边海域的大部分海域以年变化为主,有效波高的平均值在冬季达到最大值,每年12月的平均值最大.每年平均有效波高最大值大多数出现在夏季,春季则是一年中有效波高平均值最小的季节,秋季和冬季则是巨浪出现频率较高的季节.同时,对有效波高平均值的时间序列做傅立叶展开表明,对应周期为1 a变化时的波动能量占每条轨道的波高波动能量的主要分量. 相似文献
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利用TOPEX卫星高度计资料分析东中国海的风、浪场特征 总被引：3，自引：0，他引：3
利用TOPEX卫星高度计和日本气象厅浮标观测资料,对东中国海的有效波高和风速进行比较,分析了卫星高度计资料的有效性。利用有效波高和风速的3种概率密度函数分布,结合TOPEX卫星高度计资料,并采用最大似然方法对统计分布参数进行估计,结果表明,有效波高的对数-正态概率密度分布与观测资料的直方图在有效波高的整个范围内符合较好,风速的直方图与Weibul概率密度分布符合较好。同时,分析了有效波高大于4 m的巨浪在东中国海的时空分布特征,表明巨浪多出现在冬、秋两季,平均有效波高最大值出现在夏季,且主要分布在东中国海东南部。 相似文献
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TOPEX卫星高度计有效波高数据分析与极值统计预报 总被引：3，自引：0，他引：3
利用TOPEX卫生高度计测量的有效波高资料，对中国近海9个海域进行了卫星主度计的C，Ku两波段测量值的比较分析与处理,出合理的有效波高数值。利用三参数Weibull分布，以渤海海域、上海附近海域和南海东部海域的作为特定区进行有效波高的极值统计预报，并进行了统计分析。 相似文献
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利用1992年10月至2008年6月的卫星高度计融合资料对台湾岛周边海域（20°～28°N,117°～124°E）多年海平面变化进行分析.研究结果表明：（1）采用改进的月平均水位周期信号的谱分析方法计算多年来台湾岛周边海域海平面年均上升速率为0.34±0.02 cm/a,与该海域内的潮位站结果较为一致.（2）台湾岛周边海域海平面高度变化以1 a周期变化为主,其次为0.5 a、准2 a周期变化.（3）通过计算海平面异常的标准差得出多年来台湾海峡西南部海域海平面波动最为激烈.（4）分析了台湾岛周边海域海平面4个季节的变化情况,指出台湾岛周边海域海平面季节变化的主要驱动力是风场. 相似文献
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利用Jason-3卫星在国外4个主要卫星高度计定标场所在海域的测量数据,分析了这些海域的有效波高变化特性。在我国大陆沿岸选取了Jason-3卫星经过的12个海域,分析了它们的有效波高变化特性,给出了在我国大陆沿岸建设卫星测高定标场的选址建议。Bass、Corsica、Gavdos等3个定标场海域的平均有效波高约为1.1 m,说明平均有效波高1.1 m及以下的海域适用于建设定标场。选定的12个沿岸海域中,渤海及黄海海域平均有效波高小于0.8 m,显著小于东海及南海1.3～1.5 m平均有效波高,单独从有效波高的角度渤海及黄海海域更适合于建设卫星高度计定标场。 相似文献
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全球有效波高和风速的时空变化及相关关系研究 总被引：2，自引：1，他引：1
The climatology of significant wave height（SWH） and sea surface wind speed are matters of concern in the fields of both meteorology and oceanography because they are very important parameters for planning offshore structures and ship routings. The TOPEX/Poseidon altimeter, which collected data for about 13 years from September 1992 to October 2005, has measured SWHs and surface wind speeds over most of the world＇s oceans. In this paper, a study of the global spatiotemporal distributions and variations of SWH and sea surface wind speed was conducted using the TOPEX/Poseidon altimeter data set. The range and characteristics of the variations were analyzed quantitatively for the Pacific, Atlantic, and Indian oceans. Areas of rough waves and strong sea surface winds were localized precisely, and the correlation between SWH and sea surface wind speed analyzed. 相似文献
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Jason-1 Altimeter Ground Processing Look-Up Correction Tables 总被引：1，自引：0，他引：1
P. Thibaut L. Amarouche O. Z. Zanife N. Steunou P. Vincent P. Raizonville 《Marine Geodesy》2004,27(3):409-431
Poseidon-2 is the dual frequency radar altimeter embarked on the CNES/NASA oceanographic satellite Jason-1 that was launched on 7 December 2001. The primary objective of the Jason-1 mission is to continue the high accuracy time series of altimeter measurements that began with TOPEX in 1992. To achieve this goal, it is necessary to improve each component of the ground processing continually. Among these components are the look-up correction tables that are used to correct the estimations (range, significant waveheight, and sigma naught) issued from the retracking algorithms (on-board and ground). Look-up tables were first computed taking into account the prelaunch characteristics of the altimeter. They have to be updated to take into account better all the in-flight characteristics of the altimeter and all the updated ground algorithms that can impact the estimation process. The aim of this article is to describe the radar altimeter simulator of performances that has been used to compute look-up tables, to display the freshly computed look-up tables, and to discuss the consequences of these new corrections on the products provided to the users. The updated look-up correction tables allow improvement of SWH estimation, in particular with respect to TOPEX SWH data. It is also shown that no range dependency on SWH has to be looked for in these tables, and that the on-board TOPEX and Poseidon-2 tracking systems may contain the differences explaining the relative sea state bias between both altimeters. 相似文献
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P. THIBAUT L. AMAROUCHE O. Z. ZANIFE N. STEUNOU P. VINCENT P. RAIZONVILLE 《Marine Geodesy》2013,36(3-4):409-431
Poseidon-2 is the dual frequency radar altimeter embarked on the CNES/NASA oceanographic satellite Jason-1 that was launched on 7 December 2001. The primary objective of the Jason-1 mission is to continue the high accuracy time series of altimeter measurements that began with TOPEX in 1992. To achieve this goal, it is necessary to improve each component of the ground processing continually. Among these components are the look-up correction tables that are used to correct the estimations (range, significant waveheight, and sigma naught) issued from the retracking algorithms (on-board and ground). Look-up tables were first computed taking into account the prelaunch characteristics of the altimeter. They have to be updated to take into account better all the in-flight characteristics of the altimeter and all the updated ground algorithms that can impact the estimation process. The aim of this article is to describe the radar altimeter simulator of performances that has been used to compute look-up tables, to display the freshly computed look-up tables, and to discuss the consequences of these new corrections on the products provided to the users. The updated look-up correction tables allow improvement of SWH estimation, in particular with respect to TOPEX SWH data. It is also shown that no range dependency on SWH has to be looked for in these tables, and that the on-board TOPEX and Poseidon-2 tracking systems may contain the differences explaining the relative sea state bias between both altimeters. 相似文献
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利用机器学习的方法,对14个周期HY-2A卫星高度计数据:风速、有效波高和海面高度差值进行训练,探究海况偏差和风速、有效波高之间的关系,创建海况偏差核函数非参数模型(NPSSB),并与参数模型中具有代表性的BM3、BM4模型进行对比。研究表明:(1)核函数NPSSB模型能够很好的反映SSB与U、SWH之间的关系,SSB与U呈二次函数关系,SSB与SWH呈反比例函数关系;(2)核函数NPSSB模型对SSB的模拟能力与训练数据集相关,数据量越多,模拟能力越好;(3)核函数NPSSB模型与BM3、BM4模型都存在0^-0.03 m的差值,随着风速和有效波高的增加,差值的绝对值越大。 相似文献
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基于多源融合卫星高度计观测数据的南海海浪有效波高的季节变化研究 总被引：2，自引：0，他引：2
The seasonal variability of the significant wave height(SWH) in the South China Sea(SCS) is investigated using the most up-to-date gridded daily altimeter data for the period of September 2009 to August 2015. The results indicate that the SWH shows a uniform seasonal variation in the whole SCS, with its maxima occurring in December/January and minima in May. Throughout the year, the SWH in the SCS is the largest around Luzon Strait(LS) and then gradually decreases southward across the basin. The surface wind speed has a similar seasonal variation, but with different spatial distributions in most months of the year. Further analysis indicates that the observed SWH variations are dominated by swell. The wind sea height, however, is much smaller. It is the the largest in two regions southwest of Taiwan Island and southeast of Vietnam Coast during the northeasterly monsoon, while the largest in the central/southern SCS during the southwesterly monsoon. The extreme wave condition also experiences a significant seasonal variation. In most regions of the northern and central SCS, the maxima of the 99 th percentile SWH that are larger than the SWH theoretically calculated with the wind speed for the fully developed seas mainly appear in August–November, closely related to strong tropical cyclone activities.Compared with previous studies, it is also implied that the wave climate in the Pacific Ocean plays an important role in the wave climate variations in the SCS. 相似文献
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Studies of offshore wave climate based on satellite altimeter significant wave height(SWH) have widespread application value. This study used a calibrated multi-altimeter SWH dataset to investigate the wave climate characteristics in the offshore areas of China. First, the SWH measurements from 28 buoys located in China's coastal seas were compared with an Ifremer calibrated altimeter SWH dataset. Although the altimeter dataset tended to slightly overestimate SWH, it was in good agreement with the in situ data in general. The correlation coefficient was 0.97 and the root-mean-square(RMS) of differences was 0.30 m. The validation results showed a slight difference in different areas. The correlation coefficient was the maximum(0.97) and the RMS difference was the minimum(0.28 m) in the area from the East China Sea to the north of the South China Sea.The correlation coefficient of approximately 0.95 was relatively low in the seas off the Changjiang(Yangtze River) Estuary. The RMS difference was the maximum(0.32 m) in the seas off the Changjiang Estuary and was0.30 m in the Bohai Sea and the Yellow Sea. Based on the above evidence, it is confirmed that the multialtimeter wave data are reliable in China's offshore areas. Then, the characteristics of the wave field, including the frequency of huge waves and the multi-year return SWH in China's offshore seas were analyzed using the23-year altimeter wave dataset. The 23-year mean SWH generally ranged from 0.6–2.2 m. The greatest SWH appeared in the southeast of the China East Sea, the Taiwan Strait and the northeast of the South China Sea.Obvious seasonal variation of SWH was found in most areas; SWH was greater in winter and autumn than in summer and spring. Extreme waves greater than 4 m in height mainly occurred in the following areas: the southeast of the East China Sea, the south of the Ryukyu Islands, the east of Taiwan-Luzon Island, and the Dongsha Islands extending to the Zhongsha Islands, and the frequency of extreme waves was 3%–6%. Extreme waves occurred most frequently in autumn and rarely in spring. The 100-year return wave height was greatest from the northwest Pacific seas extending to southeast of the Ryukyu Islands(9–12 m), and the northeast of the South China Sea and the East China Sea had the second largest wave heights(7–11 m). For inshore areas, the100-year return wave height was the greatest in the waters off the east coast of Guangdong Province and the south coast of Zhejiang Province(7–8 m), whereas it was at a minimum in the area from the Changjiang Estuary to the Bohai Sea(4–6 m). An investigation of sampling effects indicates that when using the 1°×1°grid dataset, although the combination of nine altimeters obviously enhanced the time and space coverage of sampling, the accuracy of statistical results, particularly extreme values obtained from the dataset, still suffered from undersampling problems because the time sampling percent in each 1°×1°grid cell was always less than33%. 相似文献
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中国HY-2卫星雷达高度计有效波高真实性检验 总被引：9，自引：5，他引：4
Chinese Haiyang-2(HY-2) satellite is the first Chinese marine dynamic environment satellite. The dual-frequency(Ku and C band) radar altimeter onboard HY-2 has been working effective to provide operational significant wave height(SWH) for more than three years(October 1, 2011 to present).We validated along-track Ku-band SWH data of HY-2 satellite against National Data Buoy Center(NDBC) in-situ measurements over a time period of three years from October 1, 2011 to September 30, 2014, the root mean square error(RMSE) and mean bias of HY-2SWH is 0.38 m and(–0.13±0.35) m, respectively. We also did cross validation against Jason-2 altimeter SWH data,the RMSE and the mean bias is 0.36 m and(–0.22±0.28) m, respectively. In order to compare the statistical results between HY-2 and Jason-2 satellite SWH data, we validated the Jason-2 satellite radar altimeter along-track Ku-band SWH data against NDBC measurements using the same method. The results demonstrate the validation method in this study is scientific and the RMSE and mean bias of Jason-2 SWH data is 0.26 m and(0.00±0.26) m,respectively. We also validated both HY-2 and Jason-2 SWH data every month, the mean bias of Jason-2 SWH data almost equaled to zero all the time, while the mean bias of HY-2 SWH data was no less than –0.31 m before April2013 and dropped to zero after that time. These results indicate that the statistical results for HY-2 altimeter SWH are reliable and HY-2 altimeter along-track SWH data were steady and of high quality in the last three years. The results also indicate that HY-2 SWH data have greatly been improved and have the same accuracy with Jason-2SWH data after April, 2013. SWH data provided by HY-2 satellite radar altimeter are useful and acceptable for ocean operational applications. 相似文献
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Paul A. Hwang Steven M. Bratos William J. Teague David W. Wang Gregg A. Jacobs Donald T. Resio 《Journal of Oceanography》1999,55(2):307-325
Wind speed and wave height measured by satellite altimeters represent a good data source to the study of global and regional
wind and wave conditions. In this paper, the TOPEX altimeter wind and wave measurements in the Yellow and East China Seas
are analyzed. The results provide a glimpse on the statistical properties and the spatial distributions of the regional wind
and wave conditions. These data are excellent for use in the validation and verification of numerical simulations on global
and regional scales. The altimeter measurements are compared with model output of temporal statistics and spatial distributions.
The results show that the model simulations are in good agreement with TOPEX measurements in terms of the local mean and standard
deviation of the variables (wave height and wind speed). For the comparison of spatial distributions, the quality of agreement
between numerical simulations and altimeter measurements varies significantly from cycle to cycle of altimeter passes. In
many cases, trends in the spatial distributions of wave heights and wind speeds between simulations and measurements are opposite.
The statistics of biases, rms differences, linear regression coefficients and correlation coefficients are presented. A rather
large percentage (∼50%) of cases show poor agreement based on a combination of low correlation, large rms difference or bias,
and poor regression coefficient. There are indications that wave age is a factor affecting the performance of wave modeling
skills. Generally speaking, the error statistics in the wave field is correlated to the corresponding error statistics in
the wind field under the condition of active wind-wave generation. The error statistics between the wave field and the wind
field become less correlated for large wave ages.
This revised version was published online in August 2006 with corrections to the Cover Date. 相似文献