Observation of the Sea Surface in Southwest East China Sea by Sensor Network

利用9.25MHz海洋雷达对东海西南部的黑潮及其附近海流进行了连续观测。这一观测结果表明，黑潮具有两种流型，黑潮与八重山群岛之间的涡旋结构是由与那国岛引起的顺时针和逆时针涡旋引起的。这些涡旋的空间尺度在30 ~ 100 km之间，其移动速度在15 ~ 30 km/d之间。此外，通过对黑潮流型与石垣岛和与那国岛海平面的对比，阐明了黑潮变化是造成这两个岛屿海平面异常的主要原因。通过观测，明确了Sekiseishoukou及其周边海域的海流格局以及Sekiseishoukou与近海（东海和太平洋）的相互作用，并利用GPS浮标观测了Sekiseishoukou出生的珊瑚幼虫的输运情况。通过这一观察，澄清了大量珊瑚幼虫定居在石垣岛和西表岛周围的海底。此外，还阐明了在黑潮和附近海流的作用下，有珊瑚幼体附着在宫古岛附近海底的可能性。利用微尺度剖面仪观测了Sekiseishouk及其附近海域表层的垂直微结构。因为随着风力的增强，海面层的湍流会扩散到十米深的地方。50 cm/s的水平平均流速在海面上相对较快。

Kuroshio, where flows in southwest East China Sea, and other nearby currents are continuously observed by 9.25MHz Ocean Radar. By this observation, it is clarified that Kuroshio has two current patterns, and the eddy structure between the Kuroshio and Yaeyama Islands appeals to be caused by the clockwise and counterclockwise eddies caused by Yonaguni Island. The spatial scale of these eddies is between 30 and 100 km, and the traveling speed of these eddies is between 15 and 30 km/day. In addition, it is clarified that the abnormal sea level at Ishigaki and Yonaguni Islands depends on the variation of Kuroshio by comparing the current patterns of Kuroshio with the sea level at these Islands.The sea surface currents in Sekiseishoukou and other nearby currents are observed by 24.515MHz Ocean Radar. By this observation, it is clarified the current pattern in and around Sekiseishoukou and the interaction between Sekiseishoukou and offshore (East China Sea and Pacific Ocean).The transport of coral larval born in Sekiseishoukou is observed by GPS buoy. By this observation, it was clarified that lots of coral larval settle on the sea bottom around Ishigaki and Iriomote Islands. In addition, it was clarified the possibility that some coral larval settle on the sea bottom around Miyako Island by Kuroshio and other nearby currents.The vertical microstructure in the sea surface layer in and around Sekiseishoukou was observed by the Micro-scale profiler By this observation, supply of turbulence to the sea surface due to wind or wind wave seemed to be cause of this vertical mixing in the surface layer, because as wind blew up, turbulence in the sea surface layer spread to 10 m depth. And 50cm/s of horizontal mean velocity in the sea surface was relatively fast.