HY-2A卫星海面高度数据质量评估

对HY-2A卫星雷达高度计数据进行筛选获取有效的观测点,利用HY-2A卫星第18~23周期数据和同时在轨的Jason-2数据进行交叉点选取,对两颗卫星在交叉点海面高度异常值的差值进行统计与分析,提出了基于交叉点差值统计特征的筛除HY-2A轨道数据方法,评估了HY-2A卫星雷达高度数据质量。结果显示,HY-2A卫星18~23周期阈值筛选去除的点个数占总海洋观测点约12%,HY-2A海面高度异常与Jason-2海面高度异常的标准偏差在7.0 cm,数据精度满足设计精度要求。     

Depth Zonation, Micro habitat, and Morphology of Three Species of Acanthemblemaria (Pisces: Blennioidea) in the Guif of California, Mexico

Abstract. The utilization of the spatial resources of refuge type, size and depth placement is investigated in the three sympatric species of Acanthemblemaria at the cape region of Baja California, Mexico. A. balanorum occupies barnacle testes (Balanus tintinnabulum), A. macrospilus occupies barnacles and mollusk tubes (vermetid gastropods and pholadids), and A. crockeri occupies only mollusk tubes (pholadids). Refuge diameter overlap is higher than overlap in depth. A. crockeri consistently occupies depths below 5m. Competition experiments for barnacle refuges among the three species indicate that A. balanorum is a superior competitor for such refuges. Prior residency of a less superior species changes the outcome of refuge competition in its favor. The morphological specialization of A. balanorum and A. macrospilus is evident in a high correlation between head size and standard length. A. balanorum selects refuges with entrance diameters highly correlated to standard length.     

HY-2A卫星高度计有效波高信息提取业务化算法

2011年8月16日我国成功发射了第一颗自主海洋动力环境卫星HY-2A,有效波高是其搭载的雷达高度计可获取的重要海洋动力环境参数之一。本文详细介绍了应用于HY-2A雷达高度计的有效波高信息提取业务化算法,该算法通过迭代最小二乘拟合方法提取有效波高信息。同时,基于HY-2A雷达高度计业务化运行获取的有效波高数据,分别与Jason-2卫星高度计有效波高和NDBC浮标海浪波高数据进行了比对分析。比较结果表明,HY-2A雷达高度计与Jason-2有效波高的标准偏差为-0.26m,RMS为0.58m;HY-2A高度计与NDBC浮标数据间的标准偏差为-0.22m,RMS为0.37m。结果证明了目前应用于HY-2A雷达高度计业务化运行中的有效波高信息提取算法的可行性。     

Improvement of Sea Surface Height Measurements of HY-2A Satellite Altimeter Using Jason-2

Abstract

HY-2A, which was launched on 16 August 2011, is the Chinese first microwave ocean dynamics environment satellite. Analyses of HY-2A daily sea-level anomaly data and HY-2A–Jason-2 (H-J) dual crossover sea-level anomaly differences show that HY-2A has measurement differences that mainly refer to an orbit error. H-J crossover differences and HY-2A–HY-2A (H-H) crossover differences give an estimate of the HY-2A orbit error. Smoothing cubic-spline functions are then used to obtain a continuous estimation of the HY-2A orbit error over time. On the basis of the simultaneous global minimization of H-J dual crossover differences and H-H crossover differences, the HY-2A observation error is efficiently reduced and height measurement data that are more precise are obtained. Specifically, the range bias/trend of the HY-2A altimeter is removed effectively and the root mean square of H-J crossover sea-level anomaly differences decrease from above 60?cm to 5.64?cm, and the standard deviation of H-J crossover differences decreases from 6.68 to 5.64?cm. Furthermore, the rms and standard deviations of H-H crossover differences both decrease from 7.46 to 6.55?cm. The results show that HY-2A after correction has a measurement accuracy and precision that are comparable to those of Jason-2.     

Assessment of reprocessed sea surface height measurements derived from HY-2A radar altimeter and its application to the observation of 2015–2016 El Ni?o

Haiyang-2A(HY-2A) is China's first ocean dynamic environment satellite and the radar altimeter is one of its main payloads. One of the main purposes of the radar altimeter is to measure the sea surface height(SSH). The SSH determined from the altimeter range measurements includes some range and geophysical corrections. These corrections largely affect the accuracy of the SSH measurements. The range and the geophysical corrections are reprocessed and the altimeter waveforms in HY-2A sensor interim geophysical data set records(S-IGDR) are retracked from June 1, 2014 to June 14, 2014, and the accuracy of the reprocessed SSH measurements is evaluated.The methods of the range and geophysical corrections used to reprocess HY-2A altimeter data are validated by using these methods to reprocess the Jason-2 range and geophysical corrections and comparing the results with the range and geophysical corrections in Jason-2 geophysical dataset records(GDR) product. A crossover analysis is used to evaluate the accuracy of the reprocessed HY-2A SSH measurements. The standard deviation(STD) of the crossover SSH differences for HY-2A is around 4.53 cm while the STD of the SSH differences between HY-2A and Jason-2 is around 5.22 cm. The performance of the reprocessed HY-2A SSH measurements is significantly improved with respect to the SSH measurements derived from HY-2A interim geophysical dataset records(IGDR)product. The 2015–2016 El Ni?o has been the strongest El Ni?o event since 1997–1998. The range and the geophysical corrections in HY-2A IGDR are reprocessed and sea level anomalies are used to monitor the2015–2016 El Ni?o. The results show that the HY-2A altimeter can well observe the 2015–2016 El Ni?o.     

Predator-Prey Interaction between two Competing Sea Star Species of the Genus Astropecten

Abstract. The predator-prey interaction between two sea star species of the genus Astropecten known to be competitors was investigated at Costa Colostrai, Sardinia, Italy by means of SCUBA-Diving. It was estimated that predation of A. aranciacus would eliminate about 1 % of the prey population of A. bispinosus daily. Because densities of A. bispinosus were observed to be unaltered during the summer months, a considerable immigration of A. bispinosus into the area has to be postulated. A. bispinosus represents 40% of the dry organic matter consumed by A. aranciacus , and is one of the most important food items of this species.
A. aranciacus is not more efficient in preying upon A. bispinosus than in preying upon other food items; but efficiency is greater upon buried sea stars than upon walking ones.
Consequences for stability of the local ecosystem are discussed.     

一种测量海洋微结构的拖体

本文介绍了一种专为测量海洋微结构而研制的拖体。在测量中最大的问题是拖体的晃动。文中详细叙述了为解决这个问题，研制者在机械设计方面所采取的一系列措施，及其结果。该拖体电路部分的主要特点在文章中也有详尽的介绍。     

Application of a self adaptive method to the simulation of the tidal front in the Huanghai Sea

A self adaptive three-dimensional baroclinic model is designed. A horizontal temperature gradient is used to control the grid size, which can improve computational precision in the fronts without inordinately increasing computation in the whole area. A simulation of the development and disappearance of the front in the Huanghai Sea is conducted with this model. Simulations of temperature distribution throughout the year are also conducted. The computational result agrees well with the observation.     

DOT2008A海面地形模型在我国邻近海域的精度评估

文中首先介绍了DOT2008A模型建立的原理和方法,利用我国48个长期验潮站19 a连续观测数据验证DOT2008A模型的精度,其均方差为0.118 m,残差的标准偏差为0.086 m;联合多源测高卫星建立的海面地形模型数据验证DOT2008A的精度,均方差为0.106 m,残差的标准偏差为0.099 5 m,且其残差分布图基本符合正态分布。从实验结果来看,DOT2008A模型在我国周边海域精度较高,其建立方法较为合理,转化应用价值较高;同时与多源测高卫星建立的海面地形比较结果来看,验证了自主建立的海面地形模型的正确性,对建立我国高精度海面地形模型具有重要的借鉴意义。     

两型半潜式平台波浪作用下载荷敏感性研究

为探究半潜式平台在波浪作用下的载荷敏感特性,根据频域计算得到的水动力衍射/辐射结果,将动水压力作为输入项,利用ANSYS软件进行两型半潜式平台对波浪载荷的敏感性分析。以此对比两型平台响应特性,确定危险工况,并为平台整体结构设计提供参考。其中A型平台为柱稳式半潜平台,B型平台以A型平台为母型进行了水动力性能优化,以适用于北海海域作业环境。研究发现:两型平台的应变均在弹性形变范围内;两型平台会在相似位置处出现较大的等效弹性应力和应变分布,但相比于母型平台A,B型平台在立柱与浮体连接处也存在明显的高应力区;各波浪入射角度下,两型平台的入射波浪最危险周期不同,且存在B型平台响应大于A型平台响应的工况,因此基于水动力性能改进的B型平台,结构上可能存在不足。     

海鳗肝脏、胆囊及胰腺的显微结构

采用光镜技术研究海鳗肝脏、胆囊和胰腺的显微结构。结果表明:海鳗肝小叶不明显,肝门管区不典型。肝细胞较大,呈多边形,糖原和脂滴丰富。核呈圆形或卵圆形,1～2个。胆囊与胆管结构类似其他鱼类。胰腺长条形,紧贴肠左壁,独立存在,少量分布在胆管周围及胆囊壁上。外分泌部由腺泡和各级排泄管组成,内分泌部即胰岛,分散存在于外分泌部之间,胰岛细胞由A,B,D三种细胞组成。A细胞数量较少,位于胰岛周边,夹于B细胞之间,胞质颗粒染成红色;B细胞数量最多,位于胰岛周边,胞质颗粒染成橘黄色;D细胞一般位于胰岛中部染色浅淡的区域,胞质染淡蓝色。     

南流江河口桐花树生物动力地貌过程研究

桐花树作为红树林种群的先锋植物,其发育扩展和立地潮滩地貌变化的耦合过程是红树林生物动力地貌及生态修复研究关注的核心内容之一。本文基于2005?2019年高分辨率遥感影像、2019年10月至2020年10月的桐花树潮滩逐月沉沙量及其种群样方统计等资料,分析桐花树在南流江河口潮滩的变化特征及其与桐花树种群扩张的耦合机制。结果表明:(1)南流江河口堤外潮滩是桐花树种群的主要立地区,成年、幼年及胚胎桐花树呈带状依次出现在高潮滩、中潮滩及平均海平面附近。以平均海平面为基面,南流江河口高程为0.07 m的潮滩为桐花树一年生幼苗生长极限位置;(2)南流江河口桐花树自西北向东南快速向海扩张的格局与潮滩向海淤积前展维持一致,潮滩滩位升高成为宜林滩地是桐花树向海扩张的基础;(3)桐花树种群的消浪作用减缓水动力强度,促进泥沙在潮滩沉积,由此加速潮滩发育;低潮滩淤涨为中潮滩、高潮滩,为桐花树种群扩张提供立地条件,促进种群发育扩张。     

Numerical modelling of wave-induced currents in the presence of coastal structures

The hydrodynamic aspects of the general methodology of calculation of nearshore processes by means of numerical models are described. The paper focuses on the method implemented for calculating combined wave refraction-diffraction and reflection due to coastal structures and the associated radiation stresses.Results of numerical modelling are compared with experimental data obtained by Gourlay in the case of a shore-connected breakwater with periodic waves.A good agreement is found between both methods of investigation as concerns the spatial distribution of wave height and mean water level (wave-induced set-up). A good similarity of the wave-induced eddies in the lee of the structure is observed. A less satisfactory agreement is obtained between the velocity distributions in several profiles normal to the shore, although the overall order of magnitude is the same.A critical review of several wave-breaking criteria and sensitivity tests of the numerical model lead to advocate the use of the CERC criterion, particularly with steep beach slopes.     

On the problem of the computation of spectra of small-scale inhomogeneities in hydrophysical fields of the ocean

A novel form of correlation window employed to calculate the spectral density of a random process using a Fourier transform of the correlation function is proposed. It is shown that, concerning its metrologic characteristics, the value of the spectral density obtained does not yield the best autoregression estimates. A fast recurrent estimational algorithm is suggested to increase the efficiency of the calculational procedure.Translated by M. M. Trufanov.     

The determination of phosphonates in seawater by fractionation of the total phosphorus

A method is presented for the determination of phosphonates dissolved in seawater, which takes advantage of their chemically strong carbon-phosphorus bond resistant to phosphatase action and acid hydrolysis. One aliquot (A) of the seawater sample is submitted to phosphatase treatment followed by strong acid hydrolysis, while another aliquot (B) is submitted to total phosphorus determination by nitrate oxidation capable of breaking down phosphonates as well as phosphate esters, nucleotides and polyphosphates. The difference between the molybdate-reactive phosphate obtained from (A) and (B) gives a reasonably accurate measure of the phosphonates present in the seawater sample.     

Transient induction of 7-ethoxyresorufin-O-deethylase (EROD) activity by medium change in the rainbow trout liver cell line, RTL-W1.

Cytochrome P4501A (CYP1A) metabolizes a wide array of lipophilic xenobiotics. In fish liver, CYP1A is constitutively expressed at low levels, but xenobiotics can strongly induce CYP1A expression via a receptor-mediated pathway. While induction of hepatic CYP1A in teleosts by xenobiotics is well investigated, very little is known on the regulation of constitutive CYP1A expression and its induction by factors other than xenobiotics. In the present study we show that in the rainbow trout liver cell line, RTL-W1, CYP1A-catalyzed 7-ethoxyresorufin-O-deethylase (EROD) activity can be induced by a change of the culture medium, in the absence of xenobiotics. The increase in cellular EROD levels is of transient nature. Experiments with cell incubation solutions supplemented with various medium components indicate that photooxidized tryptophan is the agent causing the increase of EROD activity after medium change.     

A semi-analytic treatment of three-dimensional statics of marine cables

A semi-analytic approach is presented in this paper which is capable of predicting the static performance of marine cables. The solution is derived as a function of only three parameters which can be solved numerically by implementing different kinds of boundary conditions. The efficiency and accuracy of the method permit quick parametric studies for optimal selection of the system particulars which is undoubtedly useful for preliminary design. A number of numerical examples demonstrates the validity of the approach adopted.     

Large-scale vertical hydroacoustic structure of the North Atlantic and its seasonal variability

A classification based on the number and types of large-scale acoustic waveguides is proposed for the mean seasonal profiles of sound speed propagation. A scheme for North Atlantic zoning, using typical curves of the sound speed vertical distribution, is given. The channel axis's position is shown not to depend on the water mass haline properties, being controlled by the temperature field vertical stratification.Translated by Vladimir A. Puchkin.     

A method of digital spectral analysis of hydroacoustic signals

A sequence of operations for the spectral and correlation estimation of digitized random signals is suggested using a fast Fourier transform. A set of algorithms and their possible modifications, which can be used in developing the spectral estimation programmes aimed at operative derivation of processing data is represented in compressed information form.Translated by Mikhail M. Trufanov.     

一个切换混沌系统的设计与实现

利用反控制法构造了1个新的混沌系统,分析新系统的平衡点及在平衡点的特征值,分形维数,Lyapunov指数等性质,设计1个由2个混沌系统组成的可切换的实际电路并进行实验,通过1个开关选择器,电路可以实现2个子系统的功能,观察到2个子系统在各个相平面的混沌吸引子.