GPS观测数据的建模与仿真

在研究GPS系统的基础上建立了GPS观测数据的仿真模型,编制了相应的计算机程序。仿真模型包括卫星参数模型、动力学模型和观测误差模型。仿真计算表明,卫星参数模型和动力学模型真实地反映了卫星的运动规律;误差模型反映了观测环境对信号传播的影响。同时可以调节和选择仿真模型的参数,仿真选择了地面静态和地面低动态的观测数据,这对于论证GPS定轨、导航算法、设计GPS接收机等有一定的实用价值。     

海洋遥感卫星发展历程与趋势展望

海洋是对地观测卫星的重要领域,在对地观测卫星中就具有专门用于海洋观测的海洋遥感卫星。海洋遥感卫星是一种利用所搭载的遥感器对海面进行光学或微波探测来获取有关海洋水色和海洋动力环境信息的卫星。海洋卫星有效弥补了传统海洋观测手段的不足,基于多种遥感器连续对海洋的观测,使人类极大的加深了对海洋的认识,在海洋灾害的防灾减灾、资源开发、海洋维权、海洋生态和环境保护等诸多领域发挥着重要作用。本文在详细梳理西方主要航天大国海洋遥感卫星(包括了对地观测卫星中具有海洋观测功能的卫星)的发展历程,在此基础上对未来海洋遥感卫星的发展趋势进行了论述,可为我国海洋遥感卫星的发展提供技术发展参考。     

基于时空四维多尺度分析方法的卫星遥感和现场观测联合同化研究

充分融合使用卫星遥感与现场观测信息，构建高质量的水下温盐场是海洋科学研究发展的前沿课题。目前，绝大多数同化系统使用的同化方案，均需要假设要素在海表与水下存在某种人为预先设定的关系，从而导致得到的温盐分析场人为性较强，不能完全客观地反映真实的海洋状态。本研究提出了一种不做任何关系假设，仅依靠不同种类的观测资料在时间和空间上的相互补充作用，融合卫星遥感与现场观测资料，进行时空四维多尺度分析的方案。通过与分别单独同化这两类观测资料的试验结果相比，该方案既可以得到较精准的温盐剖面结构特征，又能够反映出海面中尺度变化的细节信息，最大化地提取了观测资料中的多尺度信息，实现了“1+1> 2”的效果，构建了完全客观的温盐分析场。研究结果还表明，同化卫星遥感海表面盐度资料可以有效改善温度和盐度的分析，证明了海表面盐度观测在温盐同化中的重要性。     

9914号(Dan)台风浪的后报试验研究

利用WAM第三代海浪模式的第四版本(WAMC4)对40a来造成福建沿海灾害最严重的9914号台风海浪过程进行了后报试验，并与近岸常规观测和卫星高度计有效波高资料进行了比较。与常规观测站的比较结果表明，WAMC4能较好地再现海浪的发展过程。后报结果与TOPEX/POSEIDON和ERS-2卫星观测资料的对比研究表明，风速的后报结果与卫星观测有较好的一致性，但海浪的后报比卫星高度计反演的有效波高整体略偏低。     

上海示范区卫星遥感海洋环境监测系统

上海示范区卫星遥感海洋环境监测系统是一套以地面卫星接收系统为基础、应用于上海示范区的海洋遥感环境监测应用系统。在发展相关遥感信息提取技术及资料同化技术的基础上，建立了完善可靠、可业务化运转的反演方法以及数值模式，提供海洋环境基本要素场的信息产品。该系统基于Windows95／98／NT平台，使用第四代软件开发语言IDL结合FORTRAN、C 开发，使用NetCDF数据存储格式。模式先进、功能强大、使用灵活、操作方便、系统稳定，是一个优秀的业务化海洋环境要素应用软件。     

大区域海洋遥感数据处理方法研究

<正>卫星遥感是现代海洋大尺度观测的主要技术手段。30多年来,对地观测卫星积累了大量的海洋观测数据,在区域海洋科学研究中得到了广泛的应用和关注,对遥感数据集的精度也做了许多分析和评价[1-5]。利用海洋卫星、资源卫星和气象卫星的数据,建立了长时序列连续立体观测数据库。从这些数据支撑下的研究发现,西太平洋、东太平洋、北大西洋、黑海等海域对整个海气相互作用系统起着至关重要的作用,从中找到了一些区域,如用厄尔尼诺区的异常海温指示厄尔尼诺事件[6-7]、IDO指示年代际气     

海洋观测数据的卫星传输链路—以Iridium传输链路应用分析为例

为了使全球性的海洋观测数据能够及时、可靠、准确地接收,介绍了基于卫星网络海洋观测数据传输链路的组成,对卫星传输链路的3个组成部分进行详细说明,包括:Iridium,Argos,Inmarsat和中国北斗四种卫星网络系统及比较分析,各卫星网络对应发送终端的分类分析以及陆地接收系统数据下载方式的比较分析。以Iridium网络系统为例,建设可实现全球覆盖的海洋观测数据卫星传输链路,完成现场观测数据的实时回传,为海洋观测数据卫星传输链路的建设提供示范,对比PSTN和M2M两种数据下载方式,通过实验分析,结果表明该海洋观测数据的卫星传输链路具备可行性和可靠性,可以进行业务化运行。     

现代小卫星技术在对地观测中的应用

小卫星因其研发周期短、体积小、功能强、使用灵活等特点,近年来其发展非常迅速。探讨了现代小卫星的基本概念和技术特点,分析了国内外小卫星的发展情况和发展趋势,最后阐述了小卫星、小卫星星座以及编队飞行在对地观测获取遥感信息中的应用前景。     

船舶海面观测资料的质量控制方法研究

主要根据中美合作协议，对１４０万站次的船舶海面观测资料进行标准化处理，结合此项工作经验，概括总结了一此有效的质量控制方法，包括各个环境要素资料属性与数据变化范围检验、相关性检验和统计模型检验方法，并介绍了人工审查与计算机相结合如何可疑数据。     

地球辐射收支的卫星观测与世界气候研究

一、ERB卫星观测的历史和现状 地球-大气系统(下简称地气系统)与宇宙空间的辐射能交换是影响地球气候演变和异常的决定因子,所以地球辐射收支(ERB)历来是气象学家十分关注的问题。在人类利用人造地球卫星观测地球环境的最初阶段,就考虑到了利用卫星上的传感器观测地球辐射收支的问题。人类第一颗用于气象观测目的人造卫星——探险者7号(Explorer-7)装载了用于ERB观测的仪器——威斯康星半球型黑白传感辐射计,用于观测直接太阳辐射通量、地球和大气反射的短波太阳辐射及地球和大气的放射长波辐射。在其后的实验气象卫星(TIROS系列卫星)、NOAA第一代极轨业务卫星(ESSA系列卫星),NOAA第二代极轨业务卫星(ITOS/NOAA系列卫星)、NOAA第三代极轨业务卫星(TIROS-N/NOAA系列卫星)、NOAA地球静止气象卫星(GOES系列卫星),以及 NASA(国家宇航局)的试验卫星——NIMBUS(雨云)系列卫星上先后装载了各式各样的专门用于或可用于ERB观测的仪器。     

Size-fractionated uranium isotopes in surface waters in the Jiulong Estuary in China

Surface water was collected from the Jiulong Estuary for determination of activity concentrations of uranium isotopes in different size fractions, namely, greater than 53, 10 -53, 2 - 10, 0.4 -2 μm, 10 000 u -0.4 μm and less than 10 000 u fractions by microfihration and cross-flow uhrafiltration technologies. Results indicated that most of the dissolved uranium （ 〈 0.4 μm） exis- ted in the low molecular mass fraction （ 〈 10 000 u）, and the colloidal uranium-238 （10 000 u -0.4 μm） only contributed less than 1% of the dissolved uranium-238. The fractions of colloidal uranium in the dissolved phases decreased with the increasing sa- linity. A positive linear relationship between uranium-238 activities and salinities was observed for the dissolved, colloidal and low molecular mass fractions, indicating a conservative behavior of uranium in the Jiulong Estuary. In the particulate phases （ 〉 0.4 μm）, the partitioning of uranium isotopes among different size fractions was controlled by the partitioning of particle concentrations. In the regions with salinities below 20, the partitioning of uranium-238 among different size fractions was as follows： 10 - 53 μm 〉 2 - 10 μm 〉 0.4 - 2 μm greater than above 53 μm. However, the order at the offshore station with salinities above 30 changed as follows ： 0.4 - 2 μm 〉 10 - 53 μm 〉 2 - 10 μm greater than above 53 μm. The fraction of the 0.4 - 2 μm particles increased at the offshore station, suggesting the increased contribution of the authigenic uranium. The activity ratio of uranium-234 to uranium-238 in the dissolved phases, including the low molecular mass fraction and the colloidal fraction, was larger than unity, showing the occurrence of excess uranium-234. In contrast, the activity ratio of uranium-234 to uranium-238 in all size fractions of the particulate phase was close to the equilibrium value （1.0）. The observed different values of the activity ratio of uranium-234 to uranium-238 in the dissolved phase and the partic     

夏季珠江口沉积物中营养盐剖面分布和界面交换通量

通过对夏季珠江口区域沉积物间隙水营养盐剖面分析,调查了营养盐含量分布和特征,探讨了有机物的降解特性、营养盐的底部通量估算和作用.结果表明,珠江口沉积物间隙水中营养盐以高含量铵盐为主要的存在形式,沉积物中有机物的降解反应主要在厌氧状态下进行,底部水体铵盐的增加来源于底部沉积物有机质的降解释放,而且对水体的营养盐循环有较大的贡献.     

Recent progress in submarine geosciences in China

In China submarine geosciences represents a newly established discipline of oceanography, focusing on the oceanic lithosphere, and its interface with the hydrosphere and biosphere. Recently, supported by the National High Technology Research and Development Program and other high-tech development projects, significant progress has been made in the development of advanced technologies and equipment. This en- ables the scientists in China to carry out explorations of the international seabed area in the Pacific Ocean and on the Southwest Indian Ridge. In addition, they have been active in the research activities associated the mid-ocean ridges and western Pacific marginal seas. It is anticipated that this research field will continue to be highly fruitful in the near future.     

湄洲湾夏季的初级生产力

湄洲湾１９９２年夏季的叶绿素ａ，三磷酸腺苷，碳比积累速率，初级生产力的变化范围和均值分别为０．４５－４．７２，１．４９ｍｇ／ｍ＾３；０．１２－１．０７，０．３１μｇ／ｄｍ＾３；０．０６－０．５８，０．３４ｄ＾－１；０．０７－０．３４，０．２１ｍ／（ｍ＾２．ｄ）。叶绿素ａ与三磷酸腺苷之间。初级生产力与碳比积累速率之间均呈正相关关系。叶绿素ａ三磷本能腺苷的比值为４．８，湄洲湾夏季浮游植物的生长受氮不足     

Seasonality in nutrient concentrations in Galveston Bay

In order to investigate factors controlling nutrient cycling in the shallow and turbid coastal ecosystem of Galveston Bay, data from: (1) the Texas Water Commission (TWC) database 1980–1989, and (2) salinity transects in 1989 and 1993 are presented and analyzed. Statistical regression and time-series analysis were carried out on data acquired by TWC between 1980 and 1989, in an attempt to establish seasonally of nutrient and chlorophyll-a (chl.-a.) concentrations in the bay and to determine factors which regulate these concentrations.A strong seasonality was found for phosphorus and chl.-a. in the upper and mid-bay stations. A recurring maximum for phosphate occurred in September and a chl.-a. maximum occurred regularly in March–April. It is hypothesized that benthic regeneration of phosphorus at the end of summer is responsible for the phosphate maximum. The inverse correlation of the partition coefficient (K_d) for phosphate with the concentration of suspended particulate matter (SPM), coupled to a strong enrichment of phosphate in suspended particles at low SPM concentrations, indicates additional control by geochemical and physical processes such as particle sorting and/or particle-colloid interactions. Nitrate is inversely correlated with salinity at the upper and mid-bay stations, indicating the Trinity River is a major source.Nutrient concentrations in the lower bay (East and West Bay stations) are considerably lower and less predictable, as they are not correlated with salinity or temperature. Data from the 1989 and 1993 transects confirm the yearly maximum in phosphate concentration in late summer months, with peak concentrations in the upper Trinity Bay. It is concluded that despite possible phosphate buffering by physical and geochemical mechanisms, relatively large concentration maxima recur regularly every year during the summer, possibly caused by a benthic source of phosphate.     

中国海洋腹足类分类学研究进展——纪念中国科学院海洋研究所建所70周年

中国科学院海洋研究所建所70年来，在海洋贝类分类学研究领域取得了长足发展与进步，做出一系列开创性研究成果。本文综述了建所以来我所海洋腹足类分类学研究方面的主要进展，概述了取得的主要科研成果，分析了现代腹足类分类学研究的发展趋势以及面临的挑战，并对今后的发展提出了相应对策和建议。     

Mesozooplankton in the Arctic Ocean in summer

The biomass, species and chemical composition of the mesozooplankton and their impact on lower food levels were estimated along a transect across the Arctic Ocean. Mesozooplankton biomass in the upper 200 m of the water column was significantly higher (19–42 mg DW m^-3) than has previously been reported for the Arctic Ocean, and it reached a maximum at ca. 87°N in the Amundsen Basin. The lowest values were recorded in the Chukchi Sea and Nansen Basin, where ice cover was lower (50–80%) than in the central Arctic Ocean. In the deeper strata (200–500 m) of the Canadian and Eurasian Basins, the biomass was always much lower (4.35–16.44 mg DW m^-3). The C/N (g/g) ratio for the mesozooplankton population was high (6.5–8.5) but within the documented range. These high values (when compared to 4.5 at lower latitudes) may be explained by the high lipid content. Mesozooplankton accounted for approximately 40% of the total particulate organic carbon in the upper 100 m of the water column. Mesozooplankton species composition was homogeneous along the transect, consisting mainly of copepods (70–90% of the total number). It was dominated by four large copepod species (Calanus hyperboreus, C. glacialis, C. finmarchicus and Metridia longa), which together accounted for more than 80% of the total biomass. According to measurements of gut pigment and gut turnover rates, the mesozooplankton on average ingested between 6 and 30% of their body carbon per day as phytoplankton. Microzooplankton may have provided an additional source of energy for the mesozooplankton community. These data emphasize the importance of mesozooplankton in the arctic food web and reinforce the idea that the Arctic Ocean should no longer be considered to be a “biological desert”.     

微生物对土壤中镉的固定作用

镉是一种重要的环境污染物,它通过沉淀作用、磷酸肥料的使用等排放到农田中。由于镉具有较高的蒸气压,因此,人为排放的镉大部分来自工业的挥发。排放到大气中的镉通过沉积作用转移到植物、土壤及水体中。在污染的土壤中镉被植物吸收并且在植物体内富集,通过这种机制镉进入了食物链。镉是一种诱导有机体突变的物质,能对动物和人类产生有害影响,并能够抑制植物的光合作用,因此,环境中镉的存在一直被人们所关注。     

海水双壳类受精生物学研究进展

1 研究概况,在海水双壳类中开展的大量受精生物学研究表明,绝大部分的海水双壳类为卵生型,雌雄配子被排放到海水中完成受精。排放的卵子处于第一次减数分裂前期(生发泡期)或中期。精子入卵后,受精卵恢复减数分裂,先后排放出两个极体,形成雌雄原核并最终启动卵裂。