Cooperative study of measurements of the volume and heat transports of the Kuroshio and Kuroshio Countercurrent

为了测量日本南部的黑潮及其回流（黑潮逆流），一个名为“ASUKA”的小组（隶属于对黑潮的调查）沿着一条穿越黑潮的线进行了观测，这条线被选为与测高卫星TOPEX/POSEIDON的卫星下轨迹相吻合。1993年10月，他们部署了9个系泊设施，配备了33个流速计和2个多普勒水流剖面仪和10个反向回声测深仪，这些设备维修了两年，直到1995年11月。在这段密集的观测期间，他们尽可能频繁地使用CTD（电导率-温度-深度记录仪）、XBT（消耗性深海温度记录仪）和拖曳式adcp进行测量，以估计上层速度，而系泊仪器无法充分测量这些速度。这笔赠款支持飞鸟集团的活动。根据第一年的系泊海流测量数据和重复的水文数据，我们估计了地转速度，即在标称深度700米处观测到的速度。发现黑潮在1000 m以上的绝对体积输运（估计为这些地转速度的总和）与黑潮两岸的海平面差有非常密切的关系。结合TOPEX/POSEIDON每10天的测高数据，我们首次获得了两年黑潮运输的时间序列。估计的输运量在53 Sv的平均值上下波动很大（1 Sv =10^6 m^3/秒）。年周期在时间序列中不明显，但以某些半年周期为主。

To measure the Kuroshio and its recirculation (Kuroshio Countercurrent) south of Japan, a group called ASUKA (affiliated surveys of the Kuroshio off Cape Ashizuri) carried out observations along a line crossing the Kuroshio, which was chosen to coincide with a subsatellite track of the altimetry satellite TOPEX/POSEIDON.In October 1993, they deployed nine moorings equipped with 33 current meters and two ADCPs (acoustic Doppler current profilers), and ten IESs (inverted echo sounders), which were maintained for two years until November 1995. During this intensive observation period, they carried out measurements by CTD (conductivity-temperature-depth recorder), XBT (expendable bathy-thermograph) and towed-ADCP as frequently as possible to estimate upper layr velocities, which cannot be measured adequately by the moored instruments. This Grant-in Aid supported activities of the ASUKA group.From first-year moored current meter date and repeated hydrography data, we estimated geostrophic velocities referred to velocities observed at a nominal depth of 700 m. The absolute volume transport (estimated as the sum of those geostrophic velocities) of the Kuroshio for the upper 1000 m was found to have a very tight relationship with the difference of sea level across the Kuroshio. Combination of this relationship and TOPEX/POSEIDON altimetry data obtained every 10 days provided us, for the first time, with the time series of the Kuroshio transport for two years. The estimated transport fluctuates much around an average of 53 Sv (1 Sv =10^6 m^3/sec). The annual cycle is not apparent in the time series but some semi-annual cycle is dominated.