Chlorofluorocarbons in the western North Pacific in 1993 and formation of North Pacific intermediate water

1996 ◽  
Vol 52 (4) ◽  
pp. 475-490 ◽  
Author(s):  
Takayuki Tokieda ◽  
Shuichi Watanabe ◽  
Shizuo Tsunogai
2006 ◽  
Vol 36 (3) ◽  
pp. 273-285 ◽  
Author(s):  
Yongfu Xu ◽  
Shigeaki Aoki ◽  
Koh Harada

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.


2007 ◽  
Vol 34 (2) ◽  
Author(s):  
Shinya Kouketsu ◽  
Ikuo Kaneko ◽  
Takeshi Kawano ◽  
Hiroshi Uchida ◽  
Toshimasa Doi ◽  
...  

2001 ◽  
Vol 106 (C4) ◽  
pp. 6931-6942 ◽  
Author(s):  
Ichiro Yasuda ◽  
Yutaka Hiroe ◽  
Kosei Komatsu ◽  
Kiyoshi Kawasaki ◽  
Terrence M. Joyce ◽  
...  

2019 ◽  
Vol 8 (34) ◽  
Author(s):  
Maki Teramoto ◽  
Ayumi Komatsu ◽  
Kouhei Ohnishi

The bacterial composition in North Pacific Intermediate Water (NPIW) was investigated in three different years and compared with that in other seawaters around Japan. The results indicated that bacterial composition was surprisingly stable at the same point in a mesopelagic water mass throughout the years and supported previous physicochemical observations that NPIW is distributed to Kumejima, Japan.


2020 ◽  
Author(s):  
Xun Gong ◽  
Lars Ackermann ◽  
Gerrit Lohmann

<p>North Pacific Intermediate water (NPIW) is a dominant water mass controlling ~400-1200m depth North Pacific Ocean, characterized by its low salinities and relatively lower temperatures. In the modern climate, the interplay between NPIW-related physical and biogeochemical processes among seasons determines annual-mean budget and efficiency of carbon sink into the North Pacific Ocean. Thus, to understand the NPIW physics is key to project roles of the North Pacific Ocean in changing Earth climate and carbon systems in the future. In this study, we provide a modelling view of the NPIW history since Yr 1850 (historical experiment) and its projection to near future (IPCC-defined RCP 4.2 and 8.5 experiments until Yr 2100), using new-generation Alfred Wegener Institute Earth System Model (AWI-ESM). Our results suggest an important role of regional hydroclimate feedback over the NW Pacific and Sea of Okhotsk in determining the NPIW from recent past to near future.</p>


2016 ◽  
Vol 1 (2) ◽  
pp. 17
Author(s):  
Dewi Surinati ◽  
Edi Kusmanto

<strong>Stratification of Water Mass in Lasolo Bay, Southeast Sulawesi.</strong> As a nature conservation area, Lasolo Bay should be supported by data and information of waters oceanographic. Research for stratification of water masses in Lasolo Bay was conducted. from 10 to 19 July 2011. Temperature and salinity data were obtained using CTD SBE 911 Plus preinstalled on Research Vessel Baruna Jaya VIII at intervals of 24 data per second. Current data were obtained using Vessel Mounted Acoustic Doppler Current Profiler (VMADCP) with an interval of two seconds. The results show that there are differences in the speed and direction of currents in the water column that lead to stratification of water masses. Currents that drove the water mass of Banda Sea into Lasolo Bay was caused by southeasterly winds with an average speed of 4.1 m/s. At depths of 0–50 m and 100–200 m the current dominance occurs to the northwest, while at depths of 50–100 m and 200–350 m it occurs to the south. The water mass with a salinity of 32.1–34.0 PSU and temperature 26–28°C occupied the surface layer (0–50 m). The water mass with a salinity of 34.4–34.5 PSU identified as the water mass of North Pacific Intermediate Water (NPIW) occupied two depths, i.e. 50–100 m and 200–350 m with different range of temperatures. The water mass with maximum salinity (34.5–34.6 PSU), identified as the water mass of North Pacific Subtropical Water (NPSW) also occupied two depths i.e. 100–200 m and 350 m until near the bottom with different range of temperatures<br /><br />


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