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.     

苏锡常地区浅层地下水rNa/rCl特征及其成因初探

本文从苏锡常地区浅层地下水含水介质及包气带沉积环境的角度,阐明了浅层地下水中Cl-和Na 浓度东高西低的分布特征。根据数据分析,浅层地下水中Na 与Cl-的毫克当量比值rNa/rCl与海侵形成的沉积环境和沉积历史关系密切。地下水淡化历史越长,含水层介质中吸附的Na 与地下水中的Ca2 和Mg2 之间的阳离子交换吸附程度越高,大量的Na 进入地下水中,使得rNa/rCl比值越高。     

鱼类吹风冻结保鲜的组织变化研究

利用电子显微镜观察石斑鱼冻结后的组织变化情况,研究现行吹风冻结工艺的保鲜效果。结果表明,冻结时间10h的石斑鱼组织结构中出现肌原纤维以及蛋白质受到破坏的现象,从而使其风味、营养受到严重影响。因此,有必要提高现行的吹风冻结速度。     

冲绳海槽表层沉积物中浮游有孔虫壳体的氧同位素分布特征及其影响因素

选择冲绳海槽的3个剖面A、B、C上的现代表层沉积物样品，对浮游有孔虫Globigerinoides ruber、Glo-bigerinoides sacculifer和Neogloboquadrina dutertrei进行了氧同位素分析，结果表明，几乎所有样品从G.ruber到G.sacculifer到N.dutertrei其氧同位素值均由轻变重，表明3种有孔虫其生活水层依次由浅到深，进一步证实了这3个种的生态生活习性在冲绳海槽区域与开放大洋同样一致，在槽穿海槽的A、C两个剖面上，G.ruber和N.dutertrei的氧同位素有相似的变化，从西向东氧内闰素值依次由轻变重，然后又变轻，表明剖面西侧站位有孔虫壳体氧同位素因受冲淡水影响较强而变轻，而在东侧站位受高温黑潮的影响氧同位素同样有变轻的趋势，沿海槽轴向展布的剖面B上的氧同位素变化主要受冲淡水的影响，表层水体在剖面中部和南端冲淡水影响相对较大，而次表层水只在剖面南端受冲淡水影响相对较强，剖面A、C上的N.dutertrei和G.ruber的氧同位素差值有着相反的变化趋势，在剖面A上，氧同位素差值从近陆端向近岛弧端逐渐由小变大，而在剖面C上，则逐渐由大变小，上述变化可能表明了磁部区域黑潮支流对表层水体的影响要大于次表层水体，而在南部海槽区域，黑潮暖流对次表层水体有相对较强的影响。     

干旱盆地地下水排泄区水环境初探

干旱盆地地下水排泄区以蒸发为主要排泄方式．导致水环境发生恶化，从而引发出一系列的环境问题。本文以吐哈油田南湖水源地建设为例，通过对浅层潜水和深层承压水之间的水力联系的分析，初步探讨了由开采承压水而引起的咸水下移、浅层咸水淡化以及地下水环境得以改善等问题。     

Short-term offshore extension of Brahmaputra-Ganges and Irrawaddy freshwater plumes to the central northern Bay of Bengal based on in situ and satellite observations

In this study, the short-term offshore extension of Brahmaputra-Ganges(BG) and Irrawaddy freshwater plumes to the central northern Bay of Bengal(BoB) was investigated based on in situ and satellite observations. In the summer and winter of 2015, two significant freshening events with periods of weeks were observed from a moored buoy at 15°N, 90°E in the BoB. Soil Moisture Active Passive(SMAP) satellite sea surface salinity compares well with the in situ data and shows that these freshening events are directly related to the short-term offshore extension of the BG and Irrawaddy freshwater, respectively. These data combined with the altimeter sea level anomaly data show that the offshore extending plumes result from freshwater modulated by eddies. During summer, the BG freshwater is modulated by a combination of three closely located eddies: a large anticyclonic eddy(ACE) off the northwestern BoB coast and two cyclonic eddies in the northern BoB. Consequently, the freshwater extends offshore from the river mouth and forms a long and narrow tongue-shaped plume extending southwestward to the central BoB. During winter, the Irrawaddy freshwater is modulated by two continuous ACEs evolved from Rossby wave propagating westward from the Irrawaddy Delta off Myanmar, forming a tongueshaped plume extending to the central BoB. Strong salinity fronts are formed along the boundaries of these tongue-shaped plumes. These findings confirm good capability of the SMAP data to investigate the short-term offshore extension of the BG and Irrawaddy freshwater. This study provides direct evidences of the pathways of the offshore extension of the BG and Irrawaddy freshwater and highlights the role of eddies in the northern BoB freshwater plume variability.     

Observations of Freshening in the Northwest Pacific Subtropical Gyre near Luzon Strait

Argo observations reveal that the salinity in the North Pacific subtropical gyre near Luzon Strait gradually declined by 0.2 (practical salinity scale used) from 2003 to 2007 over a depth range of 100 m to 200 m. Such freshening is also found in the outputs of the Estimating the Circulation and Climate of the Ocean (ECCO) model. The possible mechanisms for the freshening are investigated using the surface freshwater flux (E-P) data, the ECCO outputs and a salt budget equation for the upper ocean. Our analysis indicates that the magnitude of the salinity change caused by the surface freshwater flux anomaly is far smaller than observed, suggesting that the surface freshwater flux anomaly is not sufficient to account for the observed freshening. In fact, the salinity anomaly is closely linked to a pronounced freshening at the northeast corner of the study area from 2003 to 2007. The advection of salinity anomalies in the western North Pacific Ocean between 25°N and 35°N via a southwestward flow in the “C–shaped” region associated with the Kuroshio system is the main mechanism responsible for the observed freshening in the study area.

RÉSUMÉ?[Traduit par la rédaction] Les observations Argo révèlent que la salinité dans le gyre subtropical du Pacifique Nord près du détroit de Luçon a graduellement diminué de 0,2 (en utilisant l’échelle de salinité pratique) entre 2003 et 2007 dans un intervalle de profondeur de 100 à 200 m. Un adoucissement comparable s'observe aussi dans les sorties du modèle ECCO (Estimating the Circulation and Climate of the Ocean). Nous examinons les mécanismes pouvant expliquer l'adoucissement au moyen des données de flux d'eau douce en surface (E–P), des sorties de l'ECCO et de l’équation du bilan du sel pour la couche supérieure de l'océan. Notre analyse indique que l'ampleur du changement de salinité causé par l'anomalie de flux d'eau douce en surface est beaucoup plus petite que ce qui est observé, ce qui suggère que l'anomalie de flux d'eau douce en surface ne suffit pas à expliquer l'adoucissement observé. En fait, l'anomalie de salinité est étroitement liée à un adoucissement prononcé dans le coin nord-est de la zone à l’étude de 2003 à 2007. L'advection des anomalies de salinité dans l'ouest du Pacifique Nord entre 25°N et 35°N par un écoulement vers le sud-ouest dans la région en forme de « C » associée au système du Kuroshio est le principal mécanisme responsable de l'adoucissement observé dans la zone à l’étude.     

沉积环境和人类活动对苏锡常地区浅层地下水的水质效应

为指导苏锡常地区浅层地下水科学合理地开发利用,笔者从地质历史的角度分析了沉积环境对浅层地下水水质分布的影响;充分利用研究区域浅层地下水的历史水质资料,分析人类活动影响下的水质演化规律。结果表明:沉积环境对研究区的浅层地下水水质的空间分布特征具有控制作用,而人类活动对浅层地下水的水质演化具有污染和开采淡化的双重效应。     

斑节对虾淡化养殖水质特点和管理

1996、1997年福建海洋研究所在福建省龙岩市山区以盐卤水与溪水调制成养殖水体,进行斑节对虾淡化养殖试验。本文着重讨论该养殖水体中温度、盐度、溶解氧、pH等化学因子的水质特点,该水质有利于斑节对虾生长。