一个耦合模式下北赤道流分叉的初步研究

利用一个全球海洋-大气耦合模式,对北赤道流分叉的季节、年际变化特征进行了初步研究.模式结果表明北赤道流的分叉纬度,在表层大约是15.2°N,随深度而向北移动,在1000m深度大约为20°N.北赤道流分叉在春、夏季节偏南,而秋、冬季节偏北,可能主要与局地的Ekman抽吸有关.北赤道流分叉的年际变化周期表现有准2年、3～4...     

海相钾盐矿床溶滤卤水找钾指标体系: 以川东北天星桥构造寒武系深部地下卤水为例

长期工作成果显示我国现阶段常用的找钾指标Br×103/Cl值偏低.创新性地应用"以古验古"的溶滤实验与地质统计法厘清了海相蒸发盐盆地找钾指标体系,充分考虑了不同地质年代海水成分的变化,也可克服"将今论古"应用于现代海水在等温等压条件下实验数据的不足.通过对世界上典型钾盐矿床的石盐、含钾石盐及钾盐(含光卤石)进行溶滤实验...     

新疆库车坳陷西段膏盐层沉积、 地球化学特征及找钾方向

库车坳陷西段深部(5141～5218 m埋深)已有古近纪固体钾石盐矿(化)层的发现,但对该区域的膏盐层特征及成钾条件、找钾方向仍需做进一步的系统研究.以油气钻井深部膏盐层岩屑为主要对象,对库车坳陷西段膏盐层的沉积、岩石学特征以及钾、溴氯系数、Sr和S同位素等地球化学特征进行研究,并对该区盐构造特征及演化进行分析.结果表...     

热带太平洋第二类El Nio事件及其对中国气候的影响

基于热带太平洋次表层海温资料,分析了热带太平洋第二类El Nio事件海温异常的分布特征及其形成机制,讨论了与经典El Nio事件、El Nio Modoki、WP(西太平洋暖池)及CT(冷舌)El Nio事件之间的关系,揭示了第二类El Nio事件对中国降水的影响,得到以下结论。(1)第二类El Nio事件表征为热带太平洋次表层海温异常第三模态,占总方差贡献的4.7%。在海洋表面层,第二类El Nio事件暖期赤道东太平洋为沿赤道西伸的冷舌,热带中西太平洋为环绕冷舌的马蹄型大范围暖区。该型具11a和30~40a年代际振荡及3~4a年际变率,峰值多出现在春季。第二类El Nio事件是热带太平洋异常海面风应力场和赤道两侧的风应力旋度共同作用的结果,在赤道东印度洋-中西太平洋与赤道东太平洋-南美洲上空出现以反号垂直运动为特征的异常Walker环流。(2)El Nio Modoki与第二类El Nio事件有密切关系,它实质上是第二类El Nio事件次表层海温与近海面大气相互作用的结果,捕捉了第二类El Nio事件的主要信息。(3)第二类El Nio事件对中国春季及夏初降水有一定影响。在事件暖期,东海地区存在一个显著的异常反气旋性环流,其南侧的中国南方地区盛行异常东北气流,水汽来源减少,导致该地区少雨,其西侧的异常偏南气流北上直达华北地区,异常多水汽向北输送,并与北方的偏北流场相遇,导致该地区降水偏多。在第二类El Nio事件冷期相反。本文结果还指出,WP与CT El Nio事件是由经典El Nio事件第一模态与El Nio Modoki事件组合而成,它们不是独立的El Nio类型。此外,还讨论了夏半年El Nio事件对大气环流影响的物理过程。     

西北太平洋中尺度涡半径与涡动能的统计关系

中尺度涡的半径与涡动能之间的关系及其内在机制的研究,对我们理解中尺度涡旋的三维结构特征及其变异规律有很大的帮助。本文利用AVISO卫星高度计融合数据,基于流场几何特征的识别方法对西北太平洋(10°～52°N, 120°～180°E)的中尺度涡进行了识别追踪,并由此分析了该区域内中尺度涡的半径与涡动能(Eddy Kinetic Energy, EKE)的统计关系。结果表明该区域中尺度涡的半径与EKE之间存在类似翻转高斯函数的递增关系,特别是在涡旋半径达到一定程度后,EKE将不随半径的变大而继续增强。而且该关系与纬度密切相关,相同半径条件下,涡旋的EKE近似与其所在纬度的第一斜压Rossby变形半径的平方呈反比。进一步分析表明该统计关系与中尺度涡所处的发展阶段没有明显的联系。该结果为建立一个实用性的参数化、归一化的中尺度涡模型提供了一定的理论基础。     

ENSO相联系的热带太平洋上层海洋异常环流

本文使用SODA(simple ocean data assimilation)海洋同化资料,系统分析了厄尔尼诺-南方涛动(El Ni?o-Southern Oscillation,ENSO)循环中冷暖位相期间热带太平洋上层海洋环流的演变规律,探讨了形成海洋环流异常的新机制。结果表明,在厄尔尼诺成熟期,热带中东太平洋赤道潜流最弱,赤道两侧出现反气旋性环流异常;西太平洋赤道外热带海域出现气旋性环流异常,该区南、北赤道流、棉兰老流、黑潮、新几内亚沿岸潜流及南赤道逆流增强;北赤道逆流区出现异常气旋性环流串,北赤道逆流接近正常。在厄尔尼诺衰退期和拉尼娜发展期,热带中西太平洋赤道潜流达到极强,赤道两侧出现气旋性环流异常;西太平洋赤道外热带海域异常环流减弱,该处主要流场的强度减弱或处于正常状态;北赤道逆流区反转为异常西向流。结果表明, ENSO循环期间的上层海洋环流异常受到热带太平洋温跃层深度异常产生的压强梯度力异常调控,在赤道外热带海洋温跃层深度异常和科里奥利力共同作用产生大尺度海洋环流异常,而在赤道海域,海洋温跃层深度异常和Gill效应造成赤道潜流异常以及关于赤道对称的气旋或反气旋性环流异常。     

Thermohaline finestructure observed near the northern Philippine coast

Using hydrographic measurements from three recent surveys in the western tropical Pacific, this study revealed the existence and general features of thermohaline finestructure near the northern Philippine coast. Pronounced finestructures were detected in the layers of the North Pacific Tropical Water (NPTW) and the North Pacific Intermediate Water (NPIW) during all three cruises and shown to be mainly thermohaline intrusions. Characteristics of the intrusions were further investigated with spiciness curvature and salinity anomaly methods. The vertical scale of the intrusions was 20-50m and 50-100m in the NPTW and NPIW layers, respectively. Within the NPTW layer, the Turner angle distribution and correlation between salinity and density anomalies suggested that diffusive convection between surface fresh water and subsurface saline water played an important role in the development and maintenance of the intrusions. In addition, connection between thermohaline finestructure and larger-scale oceanic processes was explored using historical hydrographic data. The results reveal that the salinity field and the distribution of the intrusions in this region were largely determined by mesoscale eddies. As a result of eddy stirring, both isopycnal and diapycnal temperature/salinity gradients were strengthened, which gave rise to the development of thermohaline intrusions. The intrusions acted to enhance heat and salt fluxes and resulted in the mixing of water masses being more efficient. By linking mesoscale eddy stirring to micro-scale diffusion, thermohaline finestructure plays a vital role in the ocean energy cascade and water mass conversion in the northern Philippine Sea.     

我国高精度地心坐标框架确定方法研究

基于我国现有国家GNSS连续运行基准站数据资源,提出了实现我国区域地心坐标框架的方法,重点解决了数据处理过程中分区处理的方法和策略。首次提出了将国家基准站分成7个区域进行单天解处理,再进行联合平差的策略,以获得高效、快速的数据处理结果。将区域结果与全球结果进行联合平差,给出选取全球和我国区域框架点的原则,在此基础上对单天解解算结果进行坐标参考框架转换,得到稳定可靠的全球和区域解结果,实现我国地心坐标框架的精确确定。     

深层富钾卤水类型、勘查技术方法及工业指标建议

为修订完善现行《盐湖和盐类矿产地质勘查规范》(DZ/T0212-2002)有关深层卤水的勘查类型、勘查技术要求及工业指标等内容,作者系统收集了近年来富钾深层卤水的勘查成果及研究资料,并进行归纳总结。根据卤水的赋存条件,对深层卤水类型进行了分类,划分为孔隙型、孔隙-裂隙型和溶蚀孔洞-裂隙型三种勘查类型;针对不同卤水矿类型及已有工作程度提出了"油钾兼探"及开展专项勘查评价两种工作方法;总结了近年来对深层富钾卤水工业指标论证成果,确定深层富钾卤水矿一般工业指标:边界品位为KCl≥0. 3%～0. 5%,最低工业品位为KCl≥0. 5%～1. 0%。该成果已应用到规范修订中。     

PRELIMINARY STUDY OF RELATIONSHIP BETWEEN INTERANNUAL VARIATIONS OF SST IN SOUTH CHINA SEA AND TROPICAL INDIAN OCEAN AND SOUTH CHINA SEA MONSOON OUTBREAK

Conclusions are divided regarding the role of the variations of thermodynamics in the monsoon activity for the South China Sea region. In this study, primary eigenvectors are studied for the SSTA from East Asia to the tropical eastern Indian Ocean in May. The results show that temperature anomalies that center on Sumatra are closely related with the outbreak of the South China Sea monsoon. When the SST is warmer (cooler) than average year, it is likely that the monsoon set in late (early). It may be caused by the changes in meridional difference in thermodynamics between the Indochina Peninsula and its southern tropical oceans. Studying the temporal and spatial evolution of primary eigenvector distribution of the SSTA in the South China Sea-tropical eastern Indian Ocean from winter to summer, we find that the temperature anomalies that center around Sumatra in late spring and early summer can be traced back to the variations of the SST fields in the South China Sea in the preceding winter. Being well associated with the outbreak of the South China Sea monsoon, the latter is a signifi-cant index for it. The work helps understanding the atmospheric and oceanic background against which the South China Sea monsoon breaks out and behaves.