Using in situ data from 88 cruises 1987 to 2009 the East China Sea, downstream nutrient flux (the product of velocity and concentration) transport (integration over a section) by Kuroshio were examined. The presence maximum core middle layer was confirmed. Seasonal variation not significant much smaller than interannual variations. change speed current structure major causes for variations flux. nitrate Sea had mean value 170.8 kmol s −1 standard deviation 41.6 . seasonal ranged between...

Pacific Decadal Oscillation (PDO) index is strongly correlated with vertically integrated transport carried by the Kuroshio through East China Sea (ECS). Transport was determined from satellite altimetry calibrated in situ data and its correlation PDO (0.76) highest at zero lag. Total PDO‐correlated variation ECS‐Kuroshio Ryukyu Current about 4 Sv. In addition, negatively correlated, lag, NCEP wind‐stress‐curl over central North ECS latitudes. Sverdrup transport, calculated anomalies,...

Abstract. Based on absolute geostrophic velocity, which was calculated using repeated hydrographic data of 39 cruises from 2000 to 2009 and nitrate concentrations measured in the same areas 1964 2009, we obtained temporally averaged flux (the product velocity concentration) transport (integration over one section) four sections across Kuroshio East China Sea (sections PN TK) an area south Japan ASUKA 137E). In addition, examined section OK east Ryukyu Islands order understand how Current...

Two detachment processes of low salinity water (LSW) in the Changjiang Estuary July 2006, and role wind on detaching LSW particular, are explored with a three‐dimensional numerical model. The real‐case simulation sensitivity experiments results show that plays crucial events is highlighted three aspects. First, most important dynamic factor two LSW. Wind mixing, wind‐driven northward current wind‐induced upwelling driving forces LSW, which increase upper layer region along 30 m isobath...

Abstract In this study, for the first time, we found a Subsurface Low Potential Vorticity Water (SLPVW) to east of Taiwan Island (122–124, 21.67–23) via an array comprising 12 current and pressure‐recording inverted echo sounders (CPIESs) from 25 June 2018 29 July 2019. This SLPVW exhibits remarkable intraseasonal variability, with ∼100‐day period Island, corresponding variability in mesoscale eddies. Compared large‐scale climatological mean circulation, eddy can trap as highway westward...

Abstract Conventional methods of measuring water discharge and suspended sediment concentration (e.g., sampling moving acoustic Doppler current profiler [ADCP]) present challenges in large tidal rivers due to temporal spatial constraints. This study introduces a novel approach monitor (SSD) rivers. Total SSD exhibit notable variability the river–tidal interactions; understanding this its causes is essential for effective river management. From June November 2023, field was conducted at...

The first Chinese coastal acoustic tomography (CAT) experiment for mapping the tidal currents in Zhitouyang Bay near Zhoushan Island was successfully performed with seven stations from July 12 to 13, 2009. Using CAT, horizontal distributions of domain were calculated by inverse analysis, which travel time differences sound traveling reciprocally between station pairs are used as data. specified current structures, such strong east-west oscillation current, branched and vortices,...

Abstract Using satellite altimeter data and a long‐term altimetric transport index for the Kuroshio inflow northeast of Taiwan, effects mesoscale eddies on volume (KVT) at East Taiwan Channel branching pattern east are investigated scales from those individual events to interannual timescales. Both anticyclonic cyclonic found be able either strengthen or weaken KVT, depending relative strength mass convergence divergence produced upstream downstream eddies. The major factor influencing...

Abstract The subsurface structures of internal solitary waves were observed over two days from 27 to 29 February 2019, by bottom‐moored coastal acoustic tomography systems a path length 18.286 km in the Lombok Strait, Indonesia. One‐way travel times along transmission between stations determined for first three arrival peaks. resulting used execute four‐layer (0–50, 150–300, 300–450, and 400–603 m) temperature inversion, constructing an underdetermined problem. inverted temperatures show...

The coastal acoustic tomography system (CATS), composed of five moored stations, has been constructed to measure current fields. is developed with special considerations in mind, including the use Global Positioning System clock signals synchronization timing among multiple and differently coded Gold sequences identify corresponding individual stations from a received signal. CATS was successfully applied map structure strongly nonlinear tidal currents sea. In spite limited spatial...

Abstract Temperature variations caused by a typhoon were measured in the northern part of Hiroshima Bay four coastal acoustic tomography (CAT) systems. The horizontal distributions depth‐averaged temperature from 0 to 8 m mapped at 10 min intervals between 11 and 25 September 2013. upwelling associated diurnal internal tides reconstructed well regularized inversion based on grid segmented method, using one‐way travel time data along five successful sound transmission lines....

Abstract This study analyzes the observed subtidal currents, 1/12° global HYCOM model results, and time series to interpret seasonal interannual patterns in behavior of Kuroshio intrusion around Luzon Strait (LS). The observations include current measurements conducted at mooring station N2 (20°40.441′N, 120°38.324′E) from 7 July 2009 31 March 2011, surface geostrophic currents derived merged absolute dynamic topography, trajectory an Argo float during winter 2010–2011. Results confirmed...

Abstract For the first time, we present application of an unstructured triangular grid to Finite‐Volume Community Ocean Model using ensemble Kalman filter scheme, assimilate coastal acoustic tomography (CAT) data. The fine horizontal and vertical current field structures around island inside observation region were both reproduced well. assimilated depth‐averaged velocities had better agreement with independent Doppler profiler (ADCP) data than obtained by inversion simulation....

Abstract During the winter of 2015–2016, strongest El Niño event twenty‐first century occurred. At same time, volume transport (VT) time series South China Sea western boundary current (SCSWBC) exhibited a minimum value 3.7 Sv (1 = 1 × 10 6 m 3 s −1 ) toward southwest, indicating weakest strength ever recorded in boreal (from November to February). The (SCS) cyclonic gyre, inferred from satellite‐derived surface absolute geostrophic current, was significantly reduced. It considered that...

In order to estimate the variability of current structure and mean geostrophic volume transport in southeast Okinawa Island, round‐trip acoustic travel times between sea bottom surface at nine sites were measured by Inverted Echo Sounder with pressure gauge (PIES) from November 2000 August 2001. Vertical sections velocity are calculated using vertical profiles specific anomaly derived Gravest Empirical Mode method PIES data. upper 500 m layer over a slope shallower than 1000 depth,...

In spring 2013, 33 repeat shipboard Acoustic Doppler Current Profile (ADCP) surveys were conducted to measure the tidal current in Qiongzhou Strait (QS). The major currents and residual along a section across QS estimated using modified harmonic analysis method based on inverse technique. A simple simulation comparisons with previous observations demonstrated that are reasonable, this was able control magnitude deviation of estimation error. direction axis ellipses is generally strait....

Abstract Transverse‐vertical structure and temporal variability of the Kuroshio current across Tokara Strait during 2003–2012 measured by a ferryboat acoustic Doppler profiler with 2‐km horizontal resolution two‐day interval are presented. The passing through exhibits multicore velocity structure. Its seasonal volume transport variation is biannual for baroclinic components relative to 700 m, peaking in July December–January. However, barotropic component an annual cycle maximum December....

Abstract The abyssal current is important for water renewal and energy conversion in the deep South China Sea (SCS), it potentially contributes to upper middle circulations. A mooring array including 11 pressure‐recording inverted echo sounders was deployed northern SCS between July 2016 April 2019 observe large‐scale long‐term currents. yearly averaged flows southwestward following boundary with a maximum velocity of 2.25–2.52 cm/s. spatial structure exhibits weaker wider north, where...