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 northem Philippine coast. Pronou...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 northem Philippine coast. Pronounced finestructttres 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 20-50 m and 50-100 m 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.展开更多
文摘为提高水下滑翔机搭载的温盐深剖面仪(CTD)数据处理质量及效率,在船载CTD数据处理方法基础上,研究了国产水下滑翔机CTD数据处理方法,基于Matlab GUI编程技术设计与研发了水下滑翔机CTD数据处理软件,利用该软件处理了“海燕”水下滑翔机GPCTD观测数据并与船用SBE 911 plus CTD、XCTD及MVP300传感器成果数据进行了对比,结果表明:GPCTD观测数据经处理得到的温、盐、声剖面整体趋势与各传感器成果数据基本一致,数据质量介于各传感器之间,其中温度、声速与XCTD、MVP数据更接近,而盐度与CTD数据更吻合,本文研究将为规范处理与使用水下滑翔机海洋水文数据提供参考。
基金Supported by the National Natural Science Foundation of China (No.40890152)the Knowledge Innovation Program of Chinese Academy of Sciences (No. KZCX2-YW-Q11-02)
文摘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 northem Philippine coast. Pronounced finestructttres 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 20-50 m and 50-100 m 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.
