Varieties of a single cosmopolitan diatom species associated with surface water masses in the North Pacific

1999 ◽  
Vol 37 (2) ◽  
pp. 199-218 ◽  
Author(s):  
Yoshihiro Tanimura
Keyword(s):  
Surface Water ◽  
North Pacific ◽  
Water Masses ◽  
Diatom Species ◽  
The North ◽  
The North Pacific

Pleistocene shifts of the Subarctic Front in the North Pacific: Evidence from planktonic foraminiferal proxy data

2020 ◽  
Author(s):  
Lara Jacobi ◽  
Dirk Nürnberg ◽  
Weng-si Chao ◽  
Ralf Tiedemann ◽  
Lester Lembke- Jene ◽  
...  
Keyword(s):  
Surface Water ◽  
North Pacific ◽  
Kuroshio Current ◽  
Water Masses ◽  
Subsurface Water ◽  
The North ◽  
Tropical Water ◽  
Subarctic Front ◽  
Pleistocene Climate ◽  
The North Pacific

<p>The North Pacific plays a key role in shaping the Earth’s climate, yet there still is a lack in understanding the complex interplay of atmosphere and ocean, and their respective circulation patterns reacting to a varying Pleistocene climate. Proxy records established on marine sediment core SO264-28-2, recovered from the Emperor Seamount Chain (Suiko Seamount; ~45°N, close to the Subarctic Front) during R/V SONNE Cruise SO264 in 2018, allow to reconstruct changes of surface and subsurface water masses in order to provide unique insight in spatial and temporal shifts of North Pacific Subarctic<em> vs.</em> Subtropical gyres. According to the preliminary age model based on radiocarbon dating, benthic oxygen isotopes, combined magneto-, tephra- and biostratigraphical approaches, the only 7 m long core covers the last ~1.35 Myr. This core was chosen due to its highly characteristic pattern in magnetic susceptibility and a prominent lithological change from carbonate oozes to more siliciclastic sediment sequences at ~1.2 Ma. Thus, numerous other cores from the study area can be correlated with it suggesting this core as a reference record for the North Pacific.</p><p>A continuous and synchronous cooling of both surface and subsurface ocean temperatures since ~1.35 Ma changed rapidly at 1.2 Ma to a continuous warming surface from <4 °C to ~ 8 °C while subsurface temperature remained constant below 4 °C. The long-term diverging temperatures and increasing salinities at both surface and subsurface point to the continuous northward displacement of the Subarctic Front and an increased influence of the North Pacific Tropical Water at Suiko Seamount, with most prominent, millennial-scale, changes of the gyre system and the related Kuroshio Current during interglacials. Around ~430 ka, the influence of warm and saline subtropical surface water masses declines, reflected by a rapid decrease of sea surface temperatures of 4-5 °C and a salinity inversion, whereby the subsurface water mass becomes more saline than the surface water. After ~430 ka, interglacials are very pronounced and with the prominent presence of low saline and cooler surface waters, conditions are similar to present.</p>

scholarly journals Distributions of mixed layer properties in North Pacific water mass formation areas: comparison of Argo floats and World Ocean Atlas 2001

Ocean Science ◽  
2006 ◽  
Vol 2 (1) ◽  
pp. 61-70 ◽  
Author(s):  
F. M. Bingham ◽  
T. Suga
Keyword(s):  
Mixed Layer ◽  
North Pacific ◽  
World Ocean ◽  
Water Masses ◽  
Mode Water ◽  
The North ◽  
Central Mode Water ◽  
Central Mode ◽  
World Ocean Atlas ◽  
The North Pacific

Abstract. Winter mixed layer characteristics in the North Pacific Ocean are examined and compared between Argo floats in 2006 and the World Ocean Atlas 2001 (WOA01) climatology for a series of named water masses, North Pacific Tropical Water (NPTW), Eastern Subtropical Mode Water (ESTMW), North Pacific Subtropical Mode Water (NPSTMW), Light Central Mode Water (LCMW) and Dense Central Mode Water (DCMW). The WOA01 is found to be in good agreement with the Argo data in terms of water mass volumes, average temperature-salinity (T-S) properties, and outcrop areas. The exception to this conclusion is for the central mode waters, DCMW and LCMW, whose outcropping is shown to be much more intermittent than is apparent in the WOA01 and whose T-S properties vary from what is shown in the WOA01. Distributions of mixed layer T-S properties measured by floats are examined within the outcropping areas defined by the WOA01 and show some shifting of T-S characteristics within the confines of the named water masses. In 2006, all the water masses were warmer than climatology on average, with a magnitude of about 0.5°C. The NPTW, NPSTMW and LCMW were saltier than climatology and the ESTMW and DCMW fresher, with magnitudes of about 0.05. In order to put these results into context, differences between Argo and WOA01 were examined over the North Pacific between 20 and 45° N. A large-scsale warming and freshening is seen throughout this area, except for the western North Pacific, where results were more mixed.

scholarly journals Water masses labeled with global fallout137Cs formed by subduction in the North Pacific

2008 ◽  
Vol 35 (1) ◽  
Author(s):  
Michio Aoyama ◽  
Katsumi Hirose ◽  
Kazuhiro Nemoto ◽  
Yasushi Takatsuki ◽  
Daisuke Tsumune
Keyword(s):  
North Pacific ◽  
Water Masses ◽  
The North ◽  
The North Pacific

Ekman Transport and Zooplankton Concentration in the North Pacific Ocean

1967 ◽  
Vol 24 (3) ◽  
pp. 581-594 ◽  
Author(s):  
W. Percy Wickett
Keyword(s):  
Surface Water ◽  
Bering Sea ◽  
North Pacific ◽  
North Pacific Ocean ◽  
Ekman Transport ◽  
Sampling Area ◽  
The North ◽  
Western Bering Sea ◽  
North And South ◽  
The North Pacific

Annual concentrations of zooplankton off California varied directly, and concentrations in the western Bering Sea varied indirectly with calculated southerly components of Ekman transport in the previous year at 50°N,140°W. This point is in the area in which surface subarctic water and the deeper currents divide north and south. The underlying geostrophic flow requires approximately 1 year to reach each downstream sampling area. Summer concentrations of zooplankton at Ocean Station P, 50°N,145°W, varied with southerly and westerly components at 50°N,160°W during the previous winter. Fifty to sixty per cent of the variance of the annual concentration in zooplankton appears to be due to advection of surface water.

scholarly journals Sensitivity of the Simulated Distributions of Water Masses, CFCs, and Bomb 14C to Parameterizations of Mesoscale Tracer Transports in a Model of the North Pacific

2006 ◽  
Vol 36 (3) ◽  
pp. 273-285 ◽  
Author(s):  
Yongfu Xu ◽  
Shigeaki Aoki ◽  
Koh Harada
Keyword(s):  
North Pacific ◽  
General Circulation ◽  
Western North Pacific ◽  
North Pacific Ocean ◽  
Circulation Model ◽  
Water Masses ◽  
Intermediate Water ◽  
North Pacific Intermediate Water ◽  
The North ◽  
The North Pacific

Abstract A basinwide ocean general circulation model of the North Pacific Ocean is used to study the sensitivity of the simulated distributions of water masses, chlorofluorocarbons (CFCs), and bomb carbon-14 isotope (14C) to parameterizations of mesoscale tracer transports. Five simulations are conducted, including a run with the traditional horizontal mixing scheme and four runs with the isopycnal transport parameterization of Gent and McWilliams (GM). The four GM runs use different values of isopycnal and skew diffusivities. Simulated results show that the GM mixing scheme can help to form North Pacific Intermediate Water (NPIW). Greater isopycnal diffusivity enhances formation of NPIW. Although greater skew diffusivity can also generate NPIW, it makes the subsurface too fresh. Results from simulations of CFC uptake show that greater isopycnal diffusivity generates the best results relative to observations in the western North Pacific. The model generally underestimates the inventories of CFCs in the western North Pacific. The results from simulations of bomb 14C reproduce some observed features. Greater isopycnal diffusivity generates a longitudinal gradient of the inventory of bomb 14C from west to east, whereas greater skew diffusivity makes it reversed. It is considered that the ratio of isopycnal diffusivity to skew diffusivity is important. An increase in isopycnal diffusivity increases storage of passive tracers in the subtropical gyre.

scholarly journals The North Pacific Diatom Species Neodenticula seminae in the Modern and Holocene Sediments of the North Atlantic and Arctic

Geosciences ◽  
2020 ◽  
Vol 10 (5) ◽  
pp. 173
Author(s):  
Alexander Matul ◽  
Galina Kh. Kazarina
Keyword(s):  
North Atlantic ◽  
North Pacific ◽  
Arctic Sea Ice ◽  
The Arctic ◽  
Diatom Species ◽  
Pacific Water ◽  
The North ◽  
Holocene Sediments ◽  
The North Atlantic ◽  
The North Pacific

The paper presents micropaleontological information and observations of the North Pacific diatom species Neodenticula (N.) seminae (Simonsen and Kanaya) Akiba and Yanagisawa in the surface and Holocene sediments from the North Atlantic, Nordic, and Arctic Seas. The compilation of previously published data and new findings of this study on N. seminae in the surface sediments shows its broad occurrence as a usual element of the modern diatom microflora in the Nordic, Labrador, and Irminger Seas. The recent migration of N. seminae from its native area, the Subarctic Pacific, reflects the oceanographic shift in the late 1990s as greater transport of the warmer surface Pacific water to the Arctic causes Arctic sea-ice reduction. Micropaleontological studies of the Holocene sediments document the multiple events of N. seminae appearance in the Arctic during the latest Pleistocene and Holocene warming intervals. These observations can suggest the events of the increased influence of the North Pacific water on the Arctic environments in the past, not just during the recent warm climate amplification.

Comparative study of alkenone production in contrasting surface water environments in the north Pacific ocean

2006 ◽  
Vol 70 (18) ◽  
pp. A500
Author(s):  
B.N. Popp ◽  
F.G. Prahl ◽  
R.J. Wallsgrove ◽  
M.A. Sparrow ◽  
A.S. Pontius
Keyword(s):  
Surface Water ◽  
Pacific Ocean ◽  
Comparative Study ◽  
North Pacific ◽  
North Pacific Ocean ◽  
The North ◽  
The North Pacific

scholarly journals Surface pathway of radioactive plume of TEPCO Fukushima NPP1 released <sup>134</sup>Cs and <sup>137</sup>Cs

2013 ◽  
Vol 10 (1) ◽  
pp. 265-283 ◽  
Author(s):  
M. Aoyama ◽  
M. Uematsu ◽  
D. Tsumune ◽  
Y. Hamajima
Keyword(s):  
Surface Water ◽  
North Pacific ◽  
North Pacific Ocean ◽  
Satellite Observations ◽  
Main Body ◽  
The North ◽  
One Year ◽  
Direct Discharge ◽  
The North Pacific ◽  
Accident Site

Abstract. 134Cs and 137Cs were released to the North Pacific Ocean by two major likely pathways, direct discharge from the Fukushima NPP1 accident site and atmospheric deposition off Honshu Islands of Japan, east and northeast of the site. High density observations of 134Cs and 137Cs in the surface water were carried out by 17 cruises of cargo ships and several research vessel cruises since March 2011 till March 2012. Main body of radioactive surface plume of which activity was exceed 10 Bq m−3 had been travelling along 40° N, and reached International Date Line on March 2012 one year after the accident. A feature was that the radioactive plume was confined along 40° N when the plume reached International Date Line. A zonal speed of the radioactive plume was estimated to be about 8 cm s−1 which was consistent with zonal speeds derived by Argo floats and satellite observations at the region.

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