Tidal currents and Kuroshio transport variations in the Tokara Strait estimated from ferryboat ADCP data

Autor: Hirohiko Nakamura, Xiao-Hua Zhu, Toru Yamashiro, Ayako Nishina, Menghong Dong
Rok vydání: 2017
Předmět:
Zdroj: Journal of Geophysical Research: Oceans. 122:2120-2142
ISSN: 2169-9275
Popis: From 2003 through 2011, current surveys, using an acoustic Doppler current profiler (ADCP) mounted on the Ferry Naminoue, were conducted across the Tokara Strait (TkS). 1,234 of the resulting velocity sections were used to estimate major tidal current constituents in the TkS. The semi-diurnal M2 tidal current (maximum amplitude 27 cm s−1) was dominant among all the tidal constituents, and the diurnal K1 tidal current (maximum amplitude 21 cm s−1) was the largest among all the diurnal tidal constituents. Over the section, the ratios, relative to M2, of averaged amplitudes of M2, S2, N2, K2, K1, O1, P1, and Q1 tidal currents were 1.00:0.44:0.21:0.12:0.56:0.33:0.14:0.10. Tidal currents estimated from the ship-mounted ADCP data were in good agreement with those from the mooring ADCP data. Their root-mean-square difference for the M2 tidal current amplitude was 2.0 cm s−1. After removing the tidal currents, the annual-mean of the net volume transport (NVT) through the TkS ± its standard derivation was 23.03 ± 3.31 Sv (Sv = 106 m3 s−1). The maximum (minimum) monthly-mean NVT occurred in July (November) with 24.60 (21.47) Sv. NVT values from the ship-mounted ADCP were in good agreement with previous geostrophic volume transports calculated from conductivity temperature depth data, but the former showed much finer temporal structure than those from the geostrophic calculation. This article is protected by copyright. All rights reserved.
Databáze: OpenAIRE
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