Studies on the water-mass formation and temperature determination in the Kuroshio and Kuroshio Extension regions

我们通过这笔赠款推出了降声多普勒海流剖面仪(LADCP)。我们开发了一种用CTD数据处理LADCP的数据处理算法，精度可达几厘米/秒。在1999年7月、1999年8月至9月、2000年2月至3月、2000年10月至11月、2001年1月至2月，我们在西北太平洋进行了一系列观测，在两年中获得了180多天的观测和450多个站的LADCP资料。这种密集和广泛的LADCP观测对世界海洋学界来说是值得注意的。利用这些LADCP和CTD资料，我们发展了一种估计调整后的地转速度和垂直混合系数的分析方法。我们应用这些新方法来量化地表和地下环流，产生了大量的结果和出版物。我们发展了一种假定准地转动力学的垂直速度分析方法，得到了沿等轴面的大垂直速度和沿黑潮延伸的表层-次表层相互作用和俯冲的结果。我们还对历史数据进行了分析，20世纪初，黑潮延伸区的海温出现了年代际变化，就像后半叶一样。结合历史资料，结合散体混合层模式，阐明了黑潮及其延伸部的热量输送对确定海温的重要性。观测到了混合层深度和温度的变化，混合层深度的变化比SST移动早了几年。1980年代后期的变化可能是混合层和热量输送的变化共同作用的结果。从海洋环流模式来看，黑潮的热量输送对温度也是至关重要的。

We introduced Lowered Acoustic Doppler Current Profiler (LADCP) by this grant. We developed a data processing algorithm for LADCP with CTD data that is as accurate as a few cm/sec. With this LADCP, we performed a series of observations in the northwestern Pacific in July 1999, August-September 1999, February-March 2000, October-November 2000, January-February 2001, in which we obtained total observations amounted to be over 180days and over 450 stations of LADCP data in two years. This intensive and extensive LADCP observations are remarkable for the world oceanographic community. Using these LADCP and CTD data, we developed a analysis method for estimating adjusted geostrophic velocity and vertical mixing coefficients. We applied these new methods to quantifying surface and subsurface circulations to produce a large number of results and publications. We developed a analysis method of vertical velocity assuming quasi-geostrophic dynamics, and we obtained results of large vertical velocities along isopycnal surface and surface-subsurface interaction and subduction along the Kuroshio Extension. We also performed historical data analyzes; in early 20th century the interdecadal SST variations occurred in the Kuroshio Extension regions as in late half. With historical data combined with bulk mixed layer models, we clarified the importance of heat transport by the Kuroshio and Kuroshio Extension on the determination of SST. Regime shifts of mixed layer depths and temperature were detected and the change of mixed layer depth a few years preceded the SST shift. The shifts in late 1980s are suggested to be due to the combinations of shifts in mixed layer and heat transport. From oceanic general circulation models, heat transport by the Kuroshio is also suggested to be crucial for temperature.