热带中东太平洋海域10°N断面水团分析

本文基于实测温盐数据等资料，利用水团的浓度混合分析等方法，揭示了热带中东太平洋海域10°N断面的水团构成自上而下分别为东部赤道–热带水团、北太平洋中央水团、加利福尼亚流系水团、南太平洋中央水团、太平洋亚北极水团和太平洋深层水团。分析发现，受热带辐合带影响，9°～10°N海域常年持续的正风应力旋度诱发上升流出现，北太平洋中央水团、加利福尼亚流系水团、南太平洋中央水团和太平洋亚北极水团4个通风潜沉水团经向运动至该纬度带时被抽吸至次表层和中层，并散布在不同深度。以往研究仅指出上述4个水团在海表通风形成后将潜沉并向赤道方向运动，本研究进一步阐明了4个水团潜沉后向热带海域运动的动力机制及其在热带中东太平洋10°N断面的散布深度。研究成果揭示了热带中东太平洋水团与北太平洋副热带、亚极地和南太平洋副热带海区中上层水团间的循环过程，对认识北太平洋高–中–低纬度间物质和能量的交换和再分配具有重要科学价值。

Analysis of water masses at the 10°N section in the tropical central and eastern Pacific

Based on the survey data of temperature and salinity, concentration mixture analysis method is used to analyze water masses at 10°N section in the tropical central and eastern Pacific. From top to bottom, the water masses are the Eastern Equatorial Tropical Water Mass (E-ETWM), the North Pacific Central Water (NPCW), the California Current System waters (CCS), the South Pacific Central Water (SPCW), the Pacific Subarctic Water Mass (PSWM) and the Pacific Deep Water (PDW). It is found that the upwelling is induced by the constant positive wind stress curl throughout the year in the sea area from 9°N to 10°N under the influence of the intertropical convergence zone (ITCZ), then the four ventilated subduction water masses of the NPCW, the CCS, the SPCW and the PSWM are pumped into the subsurface and intermediate layer and distributed at different levels. Previous studies have only pointed out that the above four water masses will sink and move towards the equator after the formation of surface ventilation. This study further clarify the dynamic mechanism of the four water masses moving equatorwards as it subduction. What’s more, we reveal their corresponding depths at the 10°N section in the tropical central and eastern Pacific. The results reveal the cycling process between the tropical central and eastern Pacific water masses and the upper and intermediate layer water masses in the subtropical, subpolar regions in the North Pacific and subtropical region in South Pacific, which are of great scientific value to understand the exchange and redistribution of matter and energy between high, middle and low latitudes in the North Pacific.