scholarly journals An Exchange Window for the Injection of Antarctic Intermediate Water into the South Pacific

2007 ◽  
Vol 37 (1) ◽  
pp. 31-49 ◽  
Author(s):  
Daniele Iudicone ◽  
Keith B. Rodgers ◽  
Richard Schopp ◽  
Gurvan Madec
Keyword(s):  
Southern Ocean ◽  
Large Scale ◽  
South Pacific ◽  
Intermediate Water ◽  
The South ◽  
Antarctic Intermediate Water ◽  
South Pacific Ocean ◽  
The Pacific ◽  
Basin Scale ◽  
Circumpolar Current

Abstract Antarctic Intermediate Water (AAIW) occupies the intermediate horizon of most of the world oceans. Formed in the Southern Ocean, it is characterized by a relative salinity minimum. With a new, denser in situ National Oceanographic Data Center dataset, the authors have reanalyzed the export characteristics of AAIW from the Southern Ocean into the South Pacific Ocean. These new data show that part of the AAIW is exported from the subpolar frontal region by the large-scale circulation through an exchange window of 10° width situated east of 90°W in the southeast corner of the Pacific basin. This suggests the origin of this water to be in the Antarctic Circumpolar Current. A set of numerical modeling experiments has been used to reproduce these observed features and to demonstrate that the dynamics of the exchange window is controlled by the basin-scale meridional pressure gradient. The exchange of AAIW between the Southern and Pacific Oceans must therefore be understood in the context of the large basin-scale dynamical balance rather than simply local effects.

scholarly journals Variability of Antarctic intermediate water properties in the South Pacific Ocean

2006 ◽  
Vol 3 (6) ◽  
pp. 2021-2058 ◽  
Author(s):  
M. Tomczak
Keyword(s):  
Time Series Data ◽  
World Ocean ◽  
South Pacific ◽  
Series Data ◽  
Intermediate Water ◽  
The South ◽  
Salinity Field ◽  
Antarctic Intermediate Water ◽  
Argo Float ◽  
South Pacific Ocean

Abstract. Argo float time series data are used to study the salinity field at the depth of the salinity minimum produced by Antarctic Intermediate Water (AAIW). It is found that far from showing the smooth erosion of the minimum that would result from diffusive flow, the salinity field is characterized by features of geostrophic turbulence such as fronts, eddies and intrusions. Comparison of the Argo float observations with the climatology of the World Ocean Atlas (WOA) reveals significant differences between the two data sets. Some of the differences may have their origin in problems with the WOA data density in remote regions of the South Pacific, but most are more likely produced by interannual variations of the AAIW salinity field.

scholarly journals Variability of Antarctic intermediate Water properties in the South Pacific Ocean

Ocean Science ◽  
2007 ◽  
Vol 3 (3) ◽  
pp. 363-377 ◽  
Author(s):  
M. Tomczak
Keyword(s):  
Time Series Data ◽  
World Ocean ◽  
South Pacific ◽  
Series Data ◽  
Intermediate Water ◽  
The South ◽  
Salinity Field ◽  
Antarctic Intermediate Water ◽  
Argo Float ◽  
South Pacific Ocean

Abstract. Argo float time series data are used to study the salinity field at the depth of the salinity minimum produced by Antarctic Intermediate Water (AAIW). It is found that far from showing the smooth erosion of the minimum that would result from diffusive flow, the salinity field is characterized by features of geostrophic turbulence such as fronts, eddies and intrusions. Comparison of the Argo float observations with the climatology of the World Ocean Atlas (WOA) reveals significant differences between the two data sets. Some of the differences may have their origin in problems with the WOA data density in remote regions of the South Pacific, but most are more likely produced by interannual variations of the AAIW salinity field.

IODP Expedition 378 South Pacific Paleogene Climate: New high-resolution high-latitude Cenozoic Section

2020 ◽  
Author(s):  
Ursula Röhl ◽  
Deborah J Thomas ◽  
Laurel Childress ◽  
Keyword(s):  
Pacific Ocean ◽  
High Latitude ◽  
Global Climate ◽  
South Pacific ◽  
The South ◽  
Red Clay ◽  
South Pacific Ocean ◽  
The Pacific ◽  
The Pacific Ocean ◽  
International Ocean Discovery Program

<p>As the world’s largest ocean, the Pacific Ocean is intricately linked to major changes in the global climate system. International Ocean Discovery Program (IODP) Expedition 378 is designed to recover Paleogene sedimentary sections in the South Pacific to reconstruct key changes in oceanic and atmospheric circulation. These cores will provide an unparalleled opportunity to add crucial new data and geographic coverage to existing reconstructions of Paleogene climate and as part of a major regional slate of expeditions in the Southern Ocean to fill a critical need for high-latitude climate reconstructions. Appropriate high-latitude records are unobtainable in the Northern Hemisphere of the Pacific Ocean.</p><p>The drilling strategy included a transect of sites strategically positioned in the South Pacific to recover Paleogene carbonates buried under red clay sequences at present latitudes of 40°–52°S in 4650 – 5075 meters of water depth. Due to technical issues we no longer will be able to reach the deeper sites. Therefore, the focus of Expedition 378 will be now to obtain a continuous sedimentary record of a previously single hole, rotary-drilled, spot-cored, classic Cenozoic high-latitude DSDP Site 277 and provide a crucial, multiple hole, mostly APC-cored, continuous record of the intermediate-depth Subantarctic South Pacific Ocean from the Latest Cretaceous to late Oligocene.</p>

scholarly journals Decadal Variability in the Large-Scale Sea Surface Height Field of the South Pacific Ocean: Observations and Causes

2006 ◽  
Vol 36 (9) ◽  
pp. 1751-1762 ◽  
Author(s):  
Bo Qiu ◽  
Shuiming Chen
Keyword(s):  
Pacific Ocean ◽  
Rossby Wave ◽  
Large Scale ◽  
South Pacific ◽  
Sea Surface Height ◽  
Sea Surface ◽  
South American ◽  
The South ◽  
South Pacific Ocean ◽  
Spatially Varying

Abstract Large-scale sea surface height (SSH) changes in the extraequatorial South Pacific Ocean are investigated using satellite altimetry data of the past 12 yr. The decadal SSH signals in the 1990s were dominated by an increasing trend in the 30°–50°S band and a decreasing trend in the central South Pacific Ocean poleward of 50°S. In recent years since 2002 there has been a reversal in both of these trends. Spatially varying low-frequency SSH signals are also found in the tropical region of 10°–25°S where the decadal SSH trend is negative in the eastern basin, but positive in the western basin. To clarify the causes for these observed spatially varying SSH signals, a 1½-layer reduced-gravity model that includes the wind-driven baroclinic Rossby wave dynamics and the responses forced by SSH changes along the South American coast was adopted. The model hindcasts the spatially varying decadal trends in the midlatitude and the eastern tropical regions well. Accumulation of the wind-forced SSH anomalies along Rossby wave characteristics is found to be important for both previously reported long-term trends and their reversals in recent years. The boundary forcing associated with the time-varying SSH signals along the South American coast is crucial for understanding the observed SSH signals of all time scales in the eastern tropical South Pacific basin, but it has little impact upon the midlatitude interior SSH signals.

Dissolved inorganic Radiocarbon content of the Western Coral sea: Implications for Intermediate and Deep Water Circulation

Radiocarbon ◽  
2019 ◽  
Vol 61 (6) ◽  
pp. 1685-1696 ◽  
Author(s):  
Aymeric PM Servettaz ◽  
Yusuke Yokoyama ◽  
Shoko Hirabayashi ◽  
Markus Kienast ◽  
Yosuke Miyairi ◽  
...  
Keyword(s):  
Carbon Cycle ◽  
Deep Water ◽  
South Pacific ◽  
Intermediate Water ◽  
The South ◽  
Central Pacific ◽  
South Pacific Ocean ◽  
Deep Waters ◽  
Coral Sea ◽  
South Pacific Gyre

ABSTRACTThe South Pacific Ocean contributes to the global carbon cycle by exchanging CO2 between the atmosphere and intermediate to deep water masses. The path of the Antarctic Intermediate Water (AAIW) in the South Pacific gyre has been inferred from salinity, oxygen, and nutrient measurements, but radiocarbon (14C) measurements—a direct tracer of the carbon cycle—remain sparse. Here, we present the first radiocarbon profiles in the western Coral Sea and compare our measurements with South Pacific stations from GLODAPv2, a database of ocean hydrochemistry. Surface and subsurface waters in the Coral Sea cannot be attributed to a single source based on their Δ14C signatures, and we observe a penetration of bomb-produced 14C. AAIW in the western Coral Sea shows Δ14C values comparable to those in the South Pacific gyre, consistent with circulation of AAIW in the lower part of the southern equatorial current. The deep waters of the western Coral Sea have significantly higher 14C than the South Pacific at the same isopycnal, consistent with a northward intrusion of Circumpolar Deep Water from the Tasman Sea, along with a westward influx of deep waters from the Central Pacific. In accordance with silicate concentrations published previously, this shows the dual origin of deep waters in the Coral Sea.

Basin-scale transport of hydrothermal dissolved metals across the South Pacific Ocean

Nature ◽  
2015 ◽  
Vol 523 (7559) ◽  
pp. 200-203 ◽  
Author(s):  
Joseph A. Resing ◽  
Peter N. Sedwick ◽  
Christopher R. German ◽  
William J. Jenkins ◽  
James W. Moffett ◽  
...  
Keyword(s):  
Pacific Ocean ◽  
South Pacific ◽  
The South ◽  
Dissolved Metals ◽  
South Pacific Ocean ◽  
Basin Scale
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