scholarly journals Water Masses Characteristics at the Western Pasific Equator on August 2018

Author(s):  
Duaitd Kolibongso

The Western Pacific Equator waters are a meeting place for water masses coming from the Northern and Southern Hemispheres. This study aims to identify the characteristics of water masses formed in the waters of Northern Papua. The study of water mass characteristics in the northern waters of Papua was carried out based on reanalysis data from the World Ocean Atlas (WOA) in August 2018. There were 12 stations divided into 3 transects to be analyzed in this study, namely transect 1 and transect 2 which stretched north-south and transect 3 which stretches east-west. The analysis were performed by method of the core layer and was processed with Sofware Ocean Data View (ODV). The results showed in the waters of North Papua there was a meeting of 2 water masses from the North Pacific and South Pacific. The water masses characteristics in latitudes <5 oLU are affected by surface and intermediates of the South Pacific carried by the Papua New Guinea Coastal Current that flows along the northern coast of Papua New Guinea and into Papua waters and beyond into the waters of the Halmahera Sea. Whereas the mass of water in latitudes > 5 oLU is dominated by surface and intermediate water masses from the North Pacific carried by North Equatorial Counter Current.

2015 ◽  
Vol 6 (2) ◽  
Author(s):  
Ivonne M Radjawane ◽  
Paundra P Hadipoetranto

<p><strong><em>ABSTRACT</em></strong></p> <p><em>Measurement of ocean physical param</em><em>eter</em><em>s using the CTD was conducted by </em><em>deep water expedition </em><em>INDEX-SATAL 2010 (Indonesian Expedition Sangihe-Talaud) in July-August 2010. Th</em><em>e</em><em> </em><em>aim of this </em><em>study wa</em><em>s to</em><em> determine the characteristics of water masses around the Sangihe Talaud Water where the</em><em>re </em><em>wa</em><em>s an entry passage of </em><em> Indonesian throughflow (ITF) </em><em>at</em><em> </em><em>the </em><em>west </em><em>path</em><em>way that passed through the </em><em>primary</em><em> pathway i.e., </em><em>the Sulawesi</em><em> Sea and Makassar Strait and the secondary pathway (east pathway) that passed through the Halmahera Sea. The analyses were performed by the method of the core layer and was  processed with software Ocean Data View (ODV). The results showed that in the Sangihe Talaud waters there was a meeting water masses from the North Pacific and the South Pacific. The water mass characteristics in main pathway through the Sulawesi Sea was dominated by surface and intermediate North Pacific water masses and carried by the Mindanao Currents. While the Halmahera Sea water mass was dominated by surface and intermediate South Pacific water masses carried by the New Guinea Coastal Current that moved along the Papua New Guinea and Papua coast enters to the Halmahera Sea. </em></p> <p><em> </em></p> <p><strong><em>Keywords</em></strong><em>: Index-Satal 2010, Northern Pacific Water Mass</em><em>es</em><em>, Southern Pacific Water </em></p> <em> Masses, Sangihe Talaud</em>


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.


2008 ◽  
Vol 21 (17) ◽  
pp. 4514-4528 ◽  
Author(s):  
Lu Anne Thompson ◽  
Wei Cheng

Abstract An examination of model water masses in the North Pacific Ocean is performed in the Community Climate System version 3 (CCSM3) and its ocean-only counterpart. While the surface properties of the ocean are well represented in both simulations, biases in thermocline and intermediate-water masses exist that point to errors in both ocean model physics and the atmospheric component of the coupled model. The lack of North Pacific Intermediate Water (NPIW) in both simulations as well as the overexpression of a too-fresh Antarctic Intermediate Water (AAIW) is indicative of ocean model deficiencies. These properties reflect the difficulty of low-resolution ocean models to represent processes that control deep-water formation both in the Southern Ocean and in the Okhotsk Sea. In addition, as is typical of low-resolution ocean models, errors in the position of the Kuroshio, the North Pacific subtropical gyre western boundary current (WBC), impact the formation of the water masses that form the bulk of the thermocline as well as the properties of the NPIW. Biases that arise only in the coupled simulation include too-salty surface water in the subtropical North Pacific and too deep a thermocline, the source of which is the too-strong westerlies at midlatitudes. Biases in the location of the intertropical convergence zone (ITCZ) and the southern Pacific convergence zone (SPCZ) lead to the opposite hemispheric asymmetry in water mass structure when compared to observations. The atmospheric component of the coupled model acts to compound most ocean model biases.


2015 ◽  
Vol 6 (2) ◽  
Author(s):  
Ivonne M Radjawane ◽  
Paundra P Hadipoetranto

ABSTRACT Measurement of ocean physical parameters using the CTD was conducted by deep water expedition INDEX-SATAL 2010 (Indonesian Expedition Sangihe-Talaud) in July-August 2010. The aim of this study was to determine the characteristics of water masses around the Sangihe Talaud Water where there was an entry passage of Indonesian throughflow (ITF) at the west pathway that passed through the primary pathway i.e., the Sulawesi Sea and Makassar Strait and the secondary pathway (east pathway) that passed through the Halmahera Sea. The analyses were performed by the method of the core layer and was  processed with software Ocean Data View (ODV). The results showed that in the Sangihe Talaud waters there was a meeting water masses from the North Pacific and the South Pacific. The water mass characteristics in main pathway through the Sulawesi Sea was dominated by surface and intermediate North Pacific water masses and carried by the Mindanao Currents. While the Halmahera Sea water mass was dominated by surface and intermediate South Pacific water masses carried by the New Guinea Coastal Current that moved along the Papua New Guinea and Papua coast enters to the Halmahera Sea. Keywords: Index-Satal 2010, Northern Pacific Water Masses, Southern Pacific Water Masses, Sangihe Talaud


Ocean Science ◽  
2006 ◽  
Vol 2 (1) ◽  
pp. 61-70 ◽  
Author(s):  
F. M. Bingham ◽  
T. Suga

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.


2008 ◽  
Vol 35 (1) ◽  
Author(s):  
Michio Aoyama ◽  
Katsumi Hirose ◽  
Kazuhiro Nemoto ◽  
Yasushi Takatsuki ◽  
Daisuke Tsumune

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

&lt;p&gt;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.&lt;/p&gt;


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