长期验潮站潮位观测误差的综合探测及修复方法研究     

赵建虎  柯灏  张红梅 《武汉大学学报(信息科学版)》2011,36(12):1490-1494

在分析潮位观测值中粗差和系统误差特点及现有检测和修复方法的基础上,提出了一种基于潮汐调和分析、概率论与数理统计相结合的潮位误差综合探测和修复方法。在长期潮位站实现了粗差和系统误差的准确探测和修复。  相似文献   

吕宋海峡內潮的季节变化特征及其对背景流的响应研究   总被引：1，自引：0，他引：1  

方泳  侯一筠  经志友 《海洋学报(英文版)》2015,34(11):46-54

基于2008年秋季至2009年夏季共9个月的锚定潜标流速资料,分析了吕宋海峡西南內潮的时空特征.谱分析结果显示,该观测点全日內潮和半日內潮较为显著,尤其体现在顺时针旋转部分.除春季第二模态占优外,全日內潮主在其余三个季节均以第一模态为主,而半日內潮呈现变化的多模态结构.此外,全日內潮的动能具有明显的季节差异,冬季能量最强,夏季紧随其后,而在春、秋两季能量最小.通过分析发现,非相干运动对此季节性特征起主要作用,它反映了內潮与背景场的相互作用.然而,半日內潮却没有显著的季节性差异,而且能量较全日內潮更小,尤其在冬季,只有全日內潮动能的三分之一.同时,半日內潮的不规则变化也是与多变的背景场相关的.半日內潮的非相干部分占到了半日內潮总能量的37%左右,而全日內潮更小一些,只有22.2%.  相似文献   

SARAL/AltiKa Absolute Calibration from the Multi-Mission Corsica Facilities     

Pascal Bonnefond  Pierre Exertier  Olivier Laurain  Amandine Guillot  Nicolas Picot  Mathilde Cancet 《Marine Geodesy》2015,38(3):171-192

The geodetic Corsica site was set up in 1998 in order to perform altimeter calibration of the TOPEX/Poseidon (T/P) mission and subsequently, Jason-1 and OSTM/Jason-2. The scope of the site was widened in 2005 in order to undertake the calibration of the Envisat mission and most recently of SARAL/AltiKa. Here we present the first results from the latter mission using both indirect and direct calibration/validation approaches. The indirect approach utilizes a coastal tide gauge and, as a consequence, the altimeter derived sea surface height (SSH) needs to be corrected for the geoid slope. The direct approach utilizes a novel GPS-based system deployed offshore under the satellite ground track that permits a direct comparison with the altimeter derived SSH. The advantages and disadvantages of both systems (GPS-based and tide gauges) and methods (direct or indirect) will be described and discussed. Our results for O/IGD-R data show a very good consistency for these three kinds of products: their derived absolute SSH biases are consistent within 17 mm and their associated standard deviation ranges from 31 to 35 mm. The AltiKa absolute SSH bias derived from GPS-zodiac measurement using the direct method is ?54 ±10 mm based on the first 13 cycles.  相似文献   

Absolute Calibration of SARAL/AltiKa in Kavaratti During its Initial Calibration-Validation Phase     

K. N. Babu  A. K. Shukla  A. B. Suchandra  S. V. V. Arun Kumar  P. Bonnefond  L. Testut 《Marine Geodesy》2015,38(3):156-170

The Kavaratti calibration-validation site in India at Lakshadweep Sea has been improved to carry out absolute calibration of SARAL/AltiKa altimeter. This site is augmented with a down-looking radar gauge and a permanent GPS receiver. The Kavaratti Island is located near a repeating ground track of SARAL/AltiKa and ～12 km away from the point of closest measurement of Jason-2, SARAL/AltiKa crossover point. Additionally, the altimeter and radiometer footprints do not experience any land contamination. This article aims at presenting the initial calibration-validation results over cycles 001-011 of AltiKa. The absolute sea surface height bias has been found to be ?48 mm at Kavaratti calibration site. In this preliminary study the effect of environmental variables such as winds and pressure are not considered in calculations.  相似文献   

Spatial scale variability in shoot density and epiphytic leaves of Posidonia oceanica on Kerkennah Island (Tunisia) in relation to current tide effects          下载免费PDF全文

Mounir Ben Brahim  Lotfi Mabrouk  Asma Hamza  Mabrouka Mahfoudhi  Abderahmen Bouain  Lotfi Aleya 《Marine Ecology》2015,36(4):1311-1331

A study was undertaken of the patterns of spatial variability, epiphytic biomass and distribution of epiphytic fauna and flora of Posidonia oceanica. Samples were taken at four stations located approximately 4 km apart, exposed to different current conditions. Stations A and B, situated near the Oued Mimoun tidal channel with its relatively strong bi‐directional flows, were affected by high current tide. The other two stations, North Oued Mimoun (L1) and South Oued Mimoun (L2), were located further from the channel, in low current tide conditions. Sampling was conducted in the Attaya area of Kerkennah Island (Tunisia) in August 2009 at depths between 2 and 3 m, with the results indicating differences among the stations. Shoot density decreased when exposed to high levels of hydrodynamic activity generated by current tides whereas the epiphytic biomass of P. oceanica leaves decreased at sheltered stations located far from the channel. Epiphytic algae such as Heterokontophyta, Rhodophyta and Chlorophyta, and epiphytic fauna represented by Bryozoa, Hydrozoa, Annelida, Porifera and Tunicata, dominated the epiphytic assemblages and were abundant at the station most exposed to high current tide hydrodynamics. Cyanobacteria, however, were dominant in stations exposed to low current tide.  相似文献   

Sea-Level Variations Measured by the New Altimetry Mission SARAL/AltiKa and its Validation Based on Spatial Patterns and Temporal Curves Using Jason-2, Tide Gauge Data and an Overview of the Annual Sea Level Budget     

H. Palanisamy  A. Cazenave  O. Henry  P. Prandi  B. Meyssignac 《Marine Geodesy》2015,38(3):339-353

High-precision satellite altimeters help in measuring the variations in sea level since the early 1990s. After a number of such successful altimetry missions such as Topex/Poseidon, Jason-1, Jason-2, and Envisat, SARAL/AltiKa, a high resolution altimetry mission based on the Ka frequency band that can also cover high latitudinal zones, was launched in February 2013. Even though the data set available from this recent mission is not yet suitable for climate research owing to its short duration, in this study we perform a preliminary validation of SARAL/AltiKa sea-level data. The first part of the validation is the comparison of SARAL/AltiKa and Jason-2 sea-level data between March 2013 and August 2014 in terms of temporal mean spatial pattern. Comparisons in terms of global mean sea-level time series and latitudinal band-based mean time series are also performed. The second part of the validation is the comparison of the SARAL/AltiKa sea-level based time series with several tide gauge records covering the period of our study. Finally, an analysis of the annual sea-level budget with SARAL/AltiKa data, steric sea level, and ocean mass is performed. Results of these preliminary comparisons show good agreement with other sea-level data.  相似文献   

秦皇岛海域“褐潮”海水对卤虫、轮虫存活和摄食的影响研究   总被引：1，自引：0，他引：1  

公晗  孔凡洲  王云峰  颜天  周名江 《海洋科学》2015,39(4):30-36

为评价秦皇岛褐潮现场海水的毒性,作者利用HPLC技术及CHEMTAX,分析了2013年7月2日采自秦皇岛褐潮高峰期微型及微微型浮游植物的色素组成及群落结构;测定了卤虫(Artemia salina)、轮虫(Brachionus plicatilis)存活率和摄食量。研究表明,褐潮海水微型及微微型浮游植物中,海金藻(Pelagophyceae)占主要优势,其生物量占总生物量的72.6%。褐潮海水抑制卤虫存活,卤虫48 h存活率降至77%;对轮虫24 h存活没有显著效应。此外,褐潮海水抑制卤虫、轮虫的摄食,卤虫、轮虫8 h内摄食量分别由(5.5±0.4)ng/个降至(2.4±0.4)ng/个、由(1.5±0.2)ng/个下降至(0.9±0.1)ng/个。该结果与美国的3株褐潮藻的毒性进行了比较。CCMP 1507对卤虫存活有显著抑制作用,其他两株没有显著效应;3株褐潮藻对轮虫24 h存活都没有显著影响。暴露于3株褐潮藻中,卤虫的摄食量均显著较低;其中CCMP 1507在混合饵料中还抑制卤虫、轮虫对其他藻的摄食。对CCMP 1507各组分分析发现,该藻的毒性主要来源于藻细胞。结合现场试验与室内试验结果分析表明,秦皇岛褐潮对卤虫、轮虫有一定的毒性,其毒性与CCMP 1507的毒性相当。  相似文献   

GNSS浮标高程测量精度的影响因素研究     

翟万林  陈春涛  闫龙浩  朱建华 《海洋技术学报》2015,34(4):22-27

针对高度计定标检验的需求,研制了GNSS浮标,并在天津市于桥水库和威海市石岛镇分别进行了浮标性能测试。通过对影响浮标数据处理精度的因素进行研究,为GNSS浮标数据处理方法建立了完整的技术流程,使其满足高度计定标检验的需求。结果表明:GNSS浮标可以满足高度计定标检验的需求;但需特定的数据处理方法。(1)在基准站数据处理中,卫星截止高度角选择为5°~15°,数据采集时间不少于24 h;(2)浮标数据处理模式选择为自动模式,并对其进行移动平均滤波或中值滤波处理后,流动站解算结果最优;(3)GNSS浮标的水面高程测量精度优于1 cm;(4)受到GNSS本身的限制,当浮标距离GNSS基准站越远,浮标数据的解算精度越低。  相似文献   

基于空间自相关分析方法的渤海湾赤潮遥感叶绿素浓度研究     

向先全  路文海  许艳  曾容  陶建华 《海洋通报》2015,34(3):344-352

引入地学统计学中的空间数据分析方法,利用探索性分析、全局空间自相关和局部空间自相关分析对渤海湾赤潮爆发前后的遥感叶绿素浓度数据进行了研究。结果表明,渤海湾叶绿素浓度在相邻空间位置上具有高度的正空间自相关性;赤潮前渤海湾叶绿素浓度整体较低,但局部地区的叶绿素浓度表现出较大的上升随后几天又出现下降的异常现象;叶绿素浓度的全局空间自相关指数Moran's I值在赤潮爆发前变化幅度不大,在赤潮期间表现出一些不规则的异常变化;局部Moran's I的高-高型聚集在赤潮前主要分布在渤海湾南半部,赤潮期间出现分散并逐步转移到离岸区域,赤潮后期聚集在近岸区域。分析了其中的一些变化特征及异常情况,这些异常现象有可能是赤潮发生的预兆性信号,可为赤潮预报与应急提供一种新的尝试性模式。  相似文献   

港口高密度实时水位获取及其应用研究     

俞成明  王立平 《海洋测绘》2015,35(1):48-51

针对潮汐传播呈线性变化,水域如何实现高密度实时水位的获取问题,详细阐述了技术实现需要的资源及涉及的关键技术与数学模型。运用实例介绍了在珠江口航道水域如何获取高密度实时水位的主要技术设计内容,并对设计获取的潮位精度进行了数据验证,结果表明中误差控制在7cm以内。最后对水域高密度实时水位及其获取技术的应用前景进行了展望。  相似文献