广西近海潮汐和海流的观测分析与数值研究——Ⅱ.数值研究

基于二阶湍流闭合模型计算涡动粘性系数的 POM三维水动力模型 ,选用 0 .5′× 0 .5′细网格 ,采用动边界方法 ,把作为强迫力的潮汐和风力统一在一个模型中 ,并考虑径流作用 ,诊断计算广西近海的潮汐和海流。用 8个潮汐观测站和 2 6个锚碇浮标资料 ,对计算出的潮汐和潮流调和常数进行检验 ,证明了本研究结果的合理性。计算结果表明 :广西近海的潮汐性质基本属于正规全日潮 ;潮流性质绝大多数海区属于不正规全日潮或正规全日潮。 O1,K1和 M2 分潮最大流速均出现在钦州湾的龙门水道 ,表层分别为 5 0 ,6 0 ,40 cm/s。冬季表层存在较强的西偏南向沿岸流。铁山港外海存在一较强的逆时针环流。钦州湾龙门以北和以南分别存在半封闭逆时针环流和半封闭顺时针环流。廉州湾口存在西向风海流横向输运。冠头岭沿岸存在北偏西向补偿流。底层余流与表层的大致相同 ,但流速较小 ,沿岸流为西偏北向 ,具有补偿流性质。夏季余流与冬季相比 ,流向大致相反 ,但流速明显小     

天然热释光技术在海洋油气田勘查中的应用

沉积物热释光能有效地反映海洋环境下深部油气田引起的微弱放射性异常。热释光在不同的测试粒级、不同的岩性中的丰度不同，结果为粗粒级＞细粒级、砂岩＞粉砂质砂岩＞泥质粉砂岩＞泥岩。热释光也与部分金属元素含量有关，Ti、Ba、Zn、Fe^3 /Fe^2 与热释光呈正相关关系。热释光与烃类也呈较强的正相关性。不同采用深度热释光测量结果表明，热释光剂量随沉积物的沉积深度和沉积时间的增加而增加，深层样的热释光对油气藏的指示效果更好。     

基于地磁与红外双模探测的海洋浮标预警系统设计

设计了一种基于地磁检测与红外感应相结合、可对浮标周围异常目标进行探测和预警的控制系统。系统采用芯片级的微型磁感线圈,以及高集成度、低功耗的数据采集与总线技术,通过探测船体磁性对地磁场的扰动,监测船舶对浮标的靠近;采用芯片级的热释电红外传感器,通过探测人体红外辐射,监测浮标在正常工作期间未知人员的入侵。系统的预警采用声光报警和图像远程传输相结合的方式,现场采集的图像数据经过压缩编码后通过无线数传电台发送至远程岸基监测站,实现海洋浮标的远程预警与现场取证功能。     

Seasonality of oceanic primary production and its interannual variability from 1998 to 2007

The seasonality of primary productivity plays an important role in nutrient and carbon cycling. We quantify the seasonality of satellite-derived, oceanic net primary production (NPP) and its interannual variability during the first decade of the SeaWiFS mission (1998 to 2007) using a normalized seasonality index (NSI). The NSI, which is based upon production half-time, t(1/2), generally becomes progressively more episodic with increasing latitude in open ocean waters, spanning from a relatively constant rate of primary productivity throughout the year (mean t(1/2) ~5 months) in subtropical waters to more pulsed events (mean t(1/2) ~3 months) in subpolar waters. This relatively gradual, poleward pattern in NSI differs from recent estimates of phytoplankton bloom duration, another measure of seasonality, at lower latitudes (~40°S–40°N). These differences likely reflect the temporal component of production assessed by each metric, with NSI able to more fully capture the irregular nature of production characteristic of waters in this zonal band. The interannual variability in NSI was generally low, with higher variability observed primarily in frontal and seasonal upwelling zones. The influence of the El Niño–Southern Oscillation on this variability was clearly evident, particularly in the equatorial Pacific, where primary productivity was anomalously episodic from the date line east to the coast of South America in 1998. Yearly seasonality and the magnitude of annual production were generally positively correlated at mid-latitudes and negatively correlated at tropical latitudes, particularly in a region bordering the Pacific equatorial divergence. This implies that increases of annual production in the former region are attained over the course of a year by shorter duration but higher magnitude NPP events, while in the latter areas it results from an increased frequency or duration of similar magnitude events. Statistically significant trends in the seasonality, both positive and negative, were detected in various patches. We suggest that NSI be used together with other phenomenological characteristics of phytoplankton biomass and productivity, such as the timing of bloom initiation and duration, as a means to remotely quantify phytoplankton seasonality and monitor the response of the oceanic ecosystem to environmental variability and climate change.     

海水酸化对米氏凯伦藻和盐生杜氏藻种群增长和种间竞争的影响

大气中CO_2浓度升高导致的海水酸化改变了海洋生物赖以生存的化学环境,将对其生长、繁殖和代谢产生深远影响。本研究采用实验生态学的方法,以米氏凯伦藻(Karenia mikimotoi)和盐生杜氏藻(Dunaliella salina)为研究对象,探究在海水酸化条件下两种微藻种群增长和种间竞争关系的变化。结果发现:(1)在单培养体系中,随着二氧化碳浓度升高,米氏凯伦藻的环境负载能力(K)升高,而对其生长率进入拐点的时间(T_p)、内禀增长率(r)、进入指数增长期(T_(Ep))和静止期的时间(T_(Sp))均无显著性影响;对盐生杜氏藻而言,二氧化碳浓度升高显著降低了盐生杜氏藻的T_p和r值,而对其K、T_(Ep)、T_(Sp)均无显著性影响;(2)在共培养体系中,两种微藻的K值均受到显著抑制,与单培养体系相比差异显著(P0.05);二氧化碳升高改变了两种微藻的竞争关系,微藻之间的竞争表现为向有利于米氏凯伦藻的方向发展。(3)米氏凯伦藻去藻过滤液对盐生杜氏藻产生抑制作用,二氧化碳浓度升高加剧了这种抑制作用。     

派比安台风对上海黄浦江潮位的影响及成因探讨

2000年派比安台风产生的历史第二高潮位对上海的防汛带来严重影响。本文通过比较历史上的风暴潮，从动力机制、天文高潮与增水极值相碰头，潮波共振和水利工程的影响等四个方面分析了这次风暴潮造成的高水位，及台风余振期边缘波的影响，并用SLOSH（Sea,Lake,Overland Surge from Hurricanes)模式模拟了这次风暴潮，为防台减灾的正确决策提供了理论依据。     

A numerical study of detached shear layers in a rotating sliced cylinder

Abstract

The low Rossby number flow in a rotating cylinder with an inclined bottom, of small slope, is examined when part of the lid of the container is rotating at a slightly different rate. The resulting flow is calculated numerically by solving the governing equations for the two-dimensional geostrophic motion which approximates the flow in most of the fluid including the inertially-modified E ^¼ -layers. The presence of ageostrophic regions, on the container walls and beneath the velocity discontinuity on the lid, is accounted for in the governing equations and their boundary conditions. This study supplements previous work on this configuration, in which the zero Rossby number flow was calculated and experimental results were presented, by enabling a direct comparison to be made between the results of the low Rossby number theory and the experiments. The numerical results for a range of Rossby and Ekman numbers compare well with those from the experiments despite a severe limitation on the size of the Rossby number arising from the analysis in the ageostrophic part of the detached shear layer.     

海潮负荷对沿海地区宽幅InSAR形变监测的影响

海岸带地区是全球自然生态环境最为复杂和脆弱的地域之一,合成孔径雷达干涉测量（InSAR）技术可以为全球人类活动、气候变暖和俯冲带剧烈构造运动等背景下的大范围海岸带地理环境变化研究提供重要观测资料.海洋潮汐导致固体地球长周期形变,波长尺度为10²~10³ km的海潮负荷引入mm级至cm级的形变梯度,此类非构造信号对海岸带InSAR精密形变分析（如：大范围、微小、缓慢且非稳态构造过程等）造成显著影响.本文以宽幅模式SAR数据为例,基于多种海潮模型研究了全球典型海岸带地区（福建、智利和阿拉斯加湾）海潮负荷效应对宽幅InSAR形变监测的影响,给出了宽幅InSAR海潮负荷三维分量估计与差分相位提取方法,并进一步讨论了基于不同海潮模型估计海潮负荷位移的差异.海潮负荷影响不仅与研究范围大小有关,其形变梯度变化与研究区域地形特征存在强相关,对于长波长形变分析而言,传统平面或者曲面拟合方法难以有效分离海潮负荷位移.

     

地下水位固体潮加卸载响应比分析及预测意义

应用加卸载响应比的理论原理,对广东地下水位网的观测数据进行加卸载响应比计算,以广东及周边地区数次MS4．0级以上地震作为震例,提取可能的中期至短期的响应比异常变化,研究其异常特征以及与地震的对应关系。结果表明,在中强地震前响应比存在增大变化,大多数井的水位固体潮响应比在发震前1～4个月出现升高异常变化。     

东海八角亭海洋深井台地震监测

上海市地震局设计、建设的中国第1个真正意义上的海洋深井地震观测台位于东海石油平台上,井深780 m,安装2套JDF-1型地震计进行观测。通过对陆域地震台站记录的大地震进行分析比较、方位校准,采用单台地震分析方法,确定2009年5月—2011年6月记录到的136个地震参数,总结海域地震波形特征。结果表明,该海域地震活动性特征与当地地质构造一致。