抄録
The structure of a wind-driven flow in the Tsushima Strait is investigated with moored acoustic Doppler current profiler (ADCP) and HF radar. Two ADCPs of high and low acoustic frequencies are simultaneously used to measure velocities in both the surface boundary layer and the interior with high resolutions. The velocity relative to an interior flow in the surface boundary layer is estimated by subtracting the reference velocity (estimated from velocities at greater depths) from a velocity in the surface layer, and complex principal component analysis (PCA) of the lagged wind stress and the relative velocity is performed. Despite a short (2 weeks) observation period of relatively calm and variable wind, a clockwise velocity spiral similar to a theoretical Ekman spiral is detected as the first mode of PCA. Ekman transport estimated from the relative velocities of the first mode agrees best with Ekman transport expected from wind stress of the first mode with 11-13 hours time lag, for which the explained variance of the first mode is also largest. This indicates that a wind-driven flow is balanced with wind stress after 11-13 hours, half of the inertial period at this latitude. Eddy viscosity is also inferred from wind stress and the relative velocities of the first mode. It is found to increase from O(10-3) m2 s-1 at greater depth to O(10-2) m2 s-1 near the sea surface.
| 元の言語 | 英語 |
|---|---|
| 記事番号 | C06022 |
| ジャーナル | Journal of Geophysical Research: Oceans |
| 巻 | 112 |
| 発行部数 | 6 |
| DOI | |
| 出版物ステータス | 出版済み - 6 8 2007 |
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All Science Journal Classification (ASJC) codes
- Geophysics
- Forestry
- Oceanography
- Aquatic Science
- Ecology
- Water Science and Technology
- Soil Science
- Geochemistry and Petrology
- Earth-Surface Processes
- Atmospheric Science
- Earth and Planetary Sciences (miscellaneous)
- Space and Planetary Science
- Palaeontology
これを引用
A surface velocity spiral observed with ADCP and HF radar in the Tsushima Strait. / Yoshikawa, Y.; Matsuno, T.; Marubayashi, K.; Fukudome, K.
：: Journal of Geophysical Research: Oceans, 巻 112, 番号 6, C06022, 08.06.2007.研究成果: ジャーナルへの寄稿 › 記事
}
TY - JOUR
T1 - A surface velocity spiral observed with ADCP and HF radar in the Tsushima Strait
AU - Yoshikawa, Y.
AU - Matsuno, T.
AU - Marubayashi, K.
AU - Fukudome, K.
PY - 2007/6/8
Y1 - 2007/6/8
N2 - The structure of a wind-driven flow in the Tsushima Strait is investigated with moored acoustic Doppler current profiler (ADCP) and HF radar. Two ADCPs of high and low acoustic frequencies are simultaneously used to measure velocities in both the surface boundary layer and the interior with high resolutions. The velocity relative to an interior flow in the surface boundary layer is estimated by subtracting the reference velocity (estimated from velocities at greater depths) from a velocity in the surface layer, and complex principal component analysis (PCA) of the lagged wind stress and the relative velocity is performed. Despite a short (2 weeks) observation period of relatively calm and variable wind, a clockwise velocity spiral similar to a theoretical Ekman spiral is detected as the first mode of PCA. Ekman transport estimated from the relative velocities of the first mode agrees best with Ekman transport expected from wind stress of the first mode with 11-13 hours time lag, for which the explained variance of the first mode is also largest. This indicates that a wind-driven flow is balanced with wind stress after 11-13 hours, half of the inertial period at this latitude. Eddy viscosity is also inferred from wind stress and the relative velocities of the first mode. It is found to increase from O(10-3) m2 s-1 at greater depth to O(10-2) m2 s-1 near the sea surface.
AB - The structure of a wind-driven flow in the Tsushima Strait is investigated with moored acoustic Doppler current profiler (ADCP) and HF radar. Two ADCPs of high and low acoustic frequencies are simultaneously used to measure velocities in both the surface boundary layer and the interior with high resolutions. The velocity relative to an interior flow in the surface boundary layer is estimated by subtracting the reference velocity (estimated from velocities at greater depths) from a velocity in the surface layer, and complex principal component analysis (PCA) of the lagged wind stress and the relative velocity is performed. Despite a short (2 weeks) observation period of relatively calm and variable wind, a clockwise velocity spiral similar to a theoretical Ekman spiral is detected as the first mode of PCA. Ekman transport estimated from the relative velocities of the first mode agrees best with Ekman transport expected from wind stress of the first mode with 11-13 hours time lag, for which the explained variance of the first mode is also largest. This indicates that a wind-driven flow is balanced with wind stress after 11-13 hours, half of the inertial period at this latitude. Eddy viscosity is also inferred from wind stress and the relative velocities of the first mode. It is found to increase from O(10-3) m2 s-1 at greater depth to O(10-2) m2 s-1 near the sea surface.
UR - http://www.scopus.com/inward/record.url?scp=34548331371&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=34548331371&partnerID=8YFLogxK
U2 - 10.1029/2006JC003625
DO - 10.1029/2006JC003625
M3 - Article
AN - SCOPUS:34548331371
VL - 112
JO - Journal of Geophysical Research
JF - Journal of Geophysical Research
SN - 0148-0227
IS - 6
M1 - C06022
ER -