scholarly journals Large Variability Measured in Kuroshio Current East of Taiwan

Eos ◽  
2015 ◽  
Vol 96 ◽  
Author(s):  
Terri Cook
Keyword(s):  
Gulf Stream ◽  
Kuroshio Current ◽  
Boundary Current ◽  
Large Variability ◽  
Stable Boundary ◽  
The Pacific

Ship surveys show that the "Gulf Stream" of the Pacific is not a stable boundary current.

Two-layer gap-leaping oceanic boundary currents: experimental investigation

2014 ◽  
Vol 740 ◽  
pp. 97-113 ◽  
Author(s):  
Joseph J. Kuehl ◽  
V. A. Sheremet
Keyword(s):  
Gulf Stream ◽  
Lower Layer ◽  
Kuroshio Current ◽  
Loop Current ◽  
Boundary Current ◽  
Layer System ◽  
Open Problems ◽  
Typical Structure ◽  
Boundary Currents ◽  
Rotating Table

AbstractThe problem of oceanic gap-traversing boundary currents, such as the Kuroshio current crossing the Luzon Strait or the Gulf Stream traversing the mouth of the Gulf of Mexico, is considered. Systems such as these are known to admit two dominant states: leaping across the gap or penetrating into the gap forming a loop current. Which state the system will assume and when transitions between states will occur are open problems. Sheremet (J. Phys. Oceanogr., vol. 31, 2001, pp. 1247–1259) proposed, based on idealized barotropic numerical results, that variation in the current’s inertia is responsible for these transitions and that the system admits multiple states. Generalized versions of these results have been confirmed by barotropic rotating-table experiments (Sheremet & Kuehl, J. Phys. Oceanogr., vol. 37, 2007, 1488–1495; Kuehl & Sheremet,J. Mar. Res., vol. 67, 2009, pp. 25–42). However, the typical structure of oceanic boundary currents, such as the Gulf Stream or Kuroshio, consists of an upper-layer intensified flow riding atop a weakly circulating lower layer. To more accurately address this oceanic situation, the present work extends the above findings by considering two-layer rotating table experiments. The flow is driven by pumping water through sponges and vertical seals, creating a Sverdrup interior circulation in the upper layer which impinges on a ridge where a boundary current is formed. The $\beta $ effect is incorporated in both layers by a sloping rigid lid as well as a sloping bottom and the flow is visualized with the particle image velocimetry method. The experimental set-up is found to produce boundary currents consistent with theory. The existence of multiple states and hysteresis, characterized by a cusp topology of solutions, is found to be robust to stratification and various properties of the two-layer system are explored.

scholarly journals The East Greenland Spill Jet*

2005 ◽  
Vol 35 (6) ◽  
pp. 1037-1053 ◽  
Author(s):  
Robert S. Pickart ◽  
Daniel J. Torres ◽  
Paula S. Fratantoni
Keyword(s):  
Gulf Stream ◽  
Current System ◽  
Vertical Mixing ◽  
Relative Vorticity ◽  
Boundary Current ◽  
Velocity Measurements ◽  
East Greenland ◽  
Irminger Sea ◽  
Denmark Strait ◽  
Vorticity Analysis

Abstract High-resolution hydrographic and velocity measurements across the East Greenland shelf break south of Denmark Strait have revealed an intense, narrow current banked against the upper continental slope. This is believed to be the result of dense water cascading over the shelf edge and entraining ambient water. The current has been named the East Greenland Spill Jet. It resides beneath the East Greenland/Irminger Current and transports roughly 2 Sverdrups of water equatorward. Strong vertical mixing occurs during the spilling, although the entrainment farther downstream is minimal. A vorticity analysis reveals that the increase in cyclonic relative vorticity within the jet is partly balanced by tilting vorticity, resulting in a sharp front in potential vorticity reminiscent of the Gulf Stream. The other components of the Irminger Sea boundary current system are described, including a presentation of absolute transports.

scholarly journals Gulf Stream and Kuroshio Current are synchronized

2019 ◽  
Author(s):  
Tsubasa Kohyama ◽  
Hiroaki Miura ◽  
Shoichiro Kido
Keyword(s):  
Gulf Stream ◽  
Kuroshio Current

scholarly journals Further spreading of the non-indigenous bryozoan Celleporaria brunnea in the Mediterranean Sea: port to port morphological variations

2015 ◽  
Author(s):  
Jasmine Ferrario ◽  
Agnese Marchini ◽  
Martina Marić ◽  
Dan Minchin ◽  
Anna Occhipinti-Ambrogi
Keyword(s):  
Mediterranean Sea ◽  
Western Mediterranean ◽  
Indigenous Species ◽  
Large Variability ◽  
Morphometric Characters ◽  
Morphological Variations ◽  
The North ◽  
Western Mediterranean Sea ◽  
The Pacific ◽  
The Mediterranean

The Pacific cheilostome bryozoan Celleporaria brunnea (Hincks, 1884), a non-indigenous species already known for the Mediterranean Sea, was recorded in 2013-2014 from nine Italian port localities (Genoa, Santa Margherita Ligure, La Spezia, Leghorn, Viareggio, Olbia, Porto Rotondo, Porto Torres and Castelsardo) in the North-western Mediterranean Sea; in 2014 it was also found for the first time in the Adriatic Sea, in the marina “Kornati”, Biograd na Moru (Croatia). In Italy, specimens of C. brunnea were found in 44 out of 105 samples (48% from harbour sites ad 52% from marinas). These data confirm and update the distribution of C. brunnea in the Mediterranean Sea, and provide evidence that recreational boating is a vector responsible for the successful spread of this species. Previous literature data have shown the existence of differences in orifice and interzooidal avicularia length and width among different localities of the invaded range of C. brunnea. Therefore, measurements of orifice and avicularia were assessed for respectively 30 zooids and 8 to 30 interzooidal avicularia for both Italian and Croatian localities, and compared with literature data, in order to verify the existence of differences in the populations of C. brunnea that could reflect the geographic pattern of its invasion range. Our data show high variability of orifice measures among and within localities: zooids with broader than long orifice coexisted with others displaying longer than broad orifice, or similar values for both length and width. The morphological variation of C. brunnea in these localities, and above all the large variability of samples within single localities or even within colonies poses questions on the reliability of such morphometric characters for inter and intraspecific evaluations.

scholarly journals IODP Expedition 330: Drilling the Louisville Seamount Trail in the SW Pacific

2013 ◽  
Vol 15 ◽  
pp. 11-22 ◽  
Author(s):  
A. A. P. Koppers ◽  
T. Yamazaki ◽  
J. Geldmacher ◽  
Keyword(s):  
Mantle Plume ◽  
Mantle Source ◽  
Isotope Geochemistry ◽  
Oceanic Lithosphere ◽  
Similar Amount ◽  
Mantle Plumes ◽  
Large Variability ◽  
Sw Pacific ◽  
Integrated Ocean Drilling Program ◽  
The Pacific

Deep-Earth convection can be understood by studying hotspot volcanoes that form where mantle plumes rise up and intersect the lithosphere, the Earth's rigid outer layer. Hotspots characteristically leave age-progressive trails of volcanoes and seamounts on top of oceanic lithosphere, which in turn allow us to decipher the motion of these plates relative to "fixed" deep-mantle plumes, and their (isotope) geochemistry provides insights into the long-term evolution of mantle source regions. However, it is strongly suggested that the Hawaiian mantle plume moved ~15° south between 80 and 50 million years ago. This raises a fundamental question about other hotspot systems in the Pacific, whether or not their mantle plumes experienced a similar amount and direction of motion. Integrated Ocean Drilling Program (IODP) Expedition 330 to the Louisville Seamounts showed that the Louisville hotspot in the South Pacific behaved in a different manner, as its mantle plume remained more or less fixed around 48°S latitude during that same time period. Our findings demonstrate that the Pacific hotspots move independently and that their trajectories may be controlled by differences in subduction zone geometry. Additionally, shipboard geochemistry data shows that, in contrast to Hawaiian volcanoes, the construction of the Louisville Seamounts doesn’t involve a shield-building phase dominated by tholeiitic lavas, and trace elements confirm the rather homogenous nature of the Louisville mantle source. Both observations set Louisville apart from the Hawaiian-Emperor seamount trail, whereby the latter has been erupting abundant tholeiites (characteristically up to 95% in volume) and which exhibit a large variability in (isotope) geochemistry and their mantle source components. <br><br> doi:<a href="http://dx.doi.org/10.2204/iodp.sd.15.02.2013" target="_blank">10.2204/iodp.sd.15.02.2013</a>

Seasonal to interannual variability of the Pacific water boundary current in the Beaufort Sea

2014 ◽  
Vol 127 ◽  
pp. 1-20 ◽  
Author(s):  
Eric T. Brugler ◽  
Robert S. Pickart ◽  
G.W.K. Moore ◽  
Steven Roberts ◽  
Thomas J. Weingartner ◽  
...  
Keyword(s):  
Interannual Variability ◽  
Beaufort Sea ◽  
Boundary Current ◽  
Pacific Water ◽  
The Pacific

Ship Routing Based on the Kuroshio Current

2017 ◽  
Author(s):  
Chen Chen ◽  
Masashi Kashiwagi
Keyword(s):  
North Pacific Ocean ◽  
Kuroshio Current ◽  
Ocean Model ◽  
Ocean Current ◽  
Western Boundary ◽  
Boundary Current ◽  
Ship Maneuvering ◽  
Ship Routing ◽  
Ship Navigation ◽  
The Kuroshio

As a strong western-boundary current, the Kuroshio Current has significant effects on the ship navigation in the East China Sea (ECS). To quantitatively know more about its influence, we present simulations of the ocean current in the North Pacific Ocean using the well-known Princeton Ocean Model (POM). The high-resolution current distributions could be applied to conduct numerical simulations of the ship navigation, which utilized a ship maneuvering model known as the Mathematical Maneuvering Group (MMG). Calculation of a container ship as well as a training ship have been conducted. The simulation results of both ships can show the significant effects of ocean currents on ship’s drifting as well as speed change, which could be used to optimize cost of both fuel and time by properly utilizing the current in ship routing.

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