Estimating the geostrophic velocity obtained by HF radar observations in the upstream area of the Kuroshio

A method to extract geostrophic current in the daily mean HF radar data in the Kuroshio upstream region is established by comparison with geostrophic velocity determined from the along-track altimetry data. The estimated Ekman current in the HF velocity is 1.2% (1.5%) and 48° (38°)-clockwise rotated with respect to the daily mean wind in (outside) the Kuroshio. Furthermore, additional temporal smoothing is found necessary to remove residual ageostrophic currents such as the inertial oscillation. After removal of the ageostrophic components, the HF geostrophic velocity agrees well with that from the altimetry data with rms difference 0.14 (0.12) m/s in (outside) the Kuroshio.     

Responses of CO2 in surface water in subtropical West Pacific to El Niño event

In order to investigate the relationships between the change of TCO2, △PCO2 and SST, current, upwelling and biological activities during El Nin(～)o event in the subtropical Pacific, the responses of TCO2 and △PCO2 in surface water in the subtropical Pacific during El Nin(～)o and La Nina have been simulated using a three-dimension carbon cycle model with biota pump. The results of numerical simulations show that TCO2 in sea water increases with reducing of SST during mature phase of El Nin(～)o in the subtropical West Pacific . At the same period , the Kuroshio in this region was weakened , the zonal currents were divergence , the upwelling carried the water with high concentrations of CO2 to the sea surface , so both of TCO2 and △PCO2 in surface water were increased . But TCO2 and △pCO2 were decreased during La Nina period. These simulated results confirmed the observations in 1982/1983 , 1986/1987 ,1991/1995 and 1997/1998 El Nin(～)o events .     

Freshening of the Intermediate Waters in the Northern South China Sea over the PastSix Decades

The properties of salinity in the South China Sea (SCS), a significant marginal sea connecting the Pacific andIndian Oceans, are greatly influenced by the transport of fresh water flux between the two oceans. However, the long-termchanges in the intermediate water in the SCS have not been thoroughly studied due to limited data, particularly in relationto its thermodynamic variations. This study utilized reanalysis data products to identify a 60-year trend of freshening in theintermediate waters of the northern South China Sea (NSCS), accompanied by an expansion of low-salinity water. Thestudy also constructed salinity budget terms, including advection and entrainment processes, and conducted an analysis ofthe salinity budget to understand the impacts of external and internal dynamic processes on the freshening trend of theintermediate water in the NSCS. The analysis revealed that the freshening in the northwest Pacific Ocean and theintensification of intrusion through the Luzon Strait at intermediate levels are the primary drivers of the salinity changes inthe NSCS. Additionally, a weakened trend in the intensity of vertical entrainment also contributes to the freshening in theNSCS. This study offers new insights into the understanding of regional deep sea changes in response to variations in boththermodynamics and oceanic dynamic processes.     

基于非等间距模型的建筑物沉降预测方法研究

该文基于实测资料进行建筑物沉降预测。在灰色模型和泊松曲线模型理论的基础上,引入对非等间距数列进行变换处理的方法,从而建立了非等间距预测模型。结合建筑物沉降监测资料进行分析比较,结果表明,两种预测方法均能较好地反映建筑物的沉降趋势。     

单中继星单低轨卫星的联合定轨精度分析

针对由单中继星和单低轨卫星组成的联合定轨系统,给出了系统内不同轨道卫星摄动项的选取方案和卫星间的可见性判别模型。在模拟出含有白噪声的四程测距观测数据文件的基础上,研究了测距精度和采样弧段对联合定轨中高、低轨卫星定轨精度的影响。得出如下结论:联合定轨更有利于对低轨卫星的轨道改进;同样的采样时间条件下,测距噪声越小定轨精度越高,并且采样时间越短它的影响越明显;同样的测距噪声条件下,所用资料的采样时间越长精度越高,但当测距精度很高时,TDRS达到最好定轨精度所需的采样时间相应有所缩短。并在定出轨道后进行了轨道预报,分析了轨道预报的趋势及精度。     

泥浆性能对定向钻进铺管孔壁稳定性的影响

本文通过对泥浆性能的分析,特别是对泥浆流变参数的控制与调节在定向钻进非开挖铺管中的作用及其护壁原理的分析,简要阐述了泥浆性能对定向钻进铺管孔壁稳定性的影响,对非开挖定向钻进铺管施工有一定的指导意义。     

基于MAPGIS的土地利用数据库的更新方法讨论

本文主要对基于MAPGIS平台的土地利用数据库的更新方法进行分析讨论,并针对一些具体的数据变更叙述了其更新的方法;在本文最后还提出一些更新数据过程中需要注意的问题。     

GPS技术在山区石油地震勘探测量中的应用

针对GPS技术在山区石油地震勘探测量中的工作方式,结合2007年度南盘江一桂中地区二维地震大剖面资料采集应用GPS的工程实例,介绍GPS技术应用的新进展。通过GPS静态测量和应用RTK技术放样物理点,从测前准备、数据处理、精度分析等方面,阐述提高作业精度、有效进行质量控制的方法,旨在最大限度地发挥GPS技术在山区施工中的作用。     

寨上金矿床控矿因素及成矿远景分析

文章综述了寨上金矿床的地质特征,分析了控矿因素,认为泥盆系和二叠系是矿区的矿源层,构造对成矿有决定性的作用,说明了断裂与成矿的关系,从成矿地质环境、工程控制程度和物化探异常三个方面分析了成矿远景,指出矿区有着较大的找矿潜力。     

大庆杏南地区葡Ⅰ组三角洲前缘储层的非均质性

当油田主力油层进入高含水期时,非主力油层接替主力油层将成为必然趋势。三角洲前缘亚相储层非均质性较强,一直以来被作为非主力油层。为提高非主力油层的储量动用程度,必须精细研究三角洲前缘亚相储层非均质性特征,查明剩余油分布规律,从而有效指导油田开发的调整挖潜。利用密井网、岩矿鉴定等资料对杏南地区葡I油层组前缘亚相储层进行研究,将三角洲前缘细分为枝状、朵状、席状3种类型,详细分析了不同沉积环境下砂体的成因类型,描述了不同类型砂体在平面上、空间上的展布特征和组合关系,不同砂体内部性质的差异以及砂体内部微观孔隙结构的类型和分布特征,从平面、层间、层内以及微观特征等方面研究了三角洲前缘储层的非均质性。在此基础上分析了储层非均质性对剩余油分布的影响,指出不同三角洲前缘储层中剩余油的富集位置。