Measurement of the Kuroshio and Its Associated Luzon Strait Throughflow by Ocean Acoustic Tomography
Abstract
The Luzon Strait is a key place in the East Asian climate change study. The climate condition of the South China Sea is significantly controlled by the Luzon Strait transport (LST). Variability in the Kuroshio origin around the strait is mostly caused by the LST, and significantly affects the oceanic variability around Japan and Korea in the downstream. In spite of the importance of LST measurement, most of the previous observations are based on hydrography and the direct measurement of current is still limited in the observational period and spatial coverage. The ocean acoustic tomography (OAT) is a powerful tool that can estimate the structure of sound speed (mainly proportional to temperature) and current in the ocean. While a lot of effort has been devoted to sound speed structure measurement, application of OAT to current structure measurement is still restricted to the coastal seas. The OAT has never been applied in oceans characterized with strong internal tides and waves like the Luzon Strait. This may be caused by that the sound transmission in such oceans interacts strongly with these tides and waves and is unexpectedly disturbed not to obtain an accurate result of temperature and current. A long-term OAT experiment for current measurement is attempted at the northern part of the Luzon Strait where the Kuroshio-related current and the strong internal tides and waves occur. Four-month observation results are presented together with the new clock correction method and compared with the moored upward-looking acoustic Doppler current profiler (ADCP) data.
Document Details
- Document Type
- Technical Report
- Publication Date
- Sep 30, 2009
- Accession Number
- ADA531728
Entities
People
- Arata Kaneko
Organizations
- Hiroshima University