scholarly journals Neodymium Evidence for Increased Circumpolar Deep Water Flow to the North Pacific During the Middle Miocene Climate Transition

2018 ◽  
Vol 33 (7) ◽  
pp. 672-682 ◽  
Author(s):  
Sev Kender ◽  
Kara A. Bogus ◽  
Ty D. Cobb ◽  
Deborah J. Thomas
Keyword(s):  
Water Flow ◽  
Deep Water ◽  
North Pacific ◽  
Middle Miocene ◽  
Circumpolar Deep Water ◽  
The North ◽  
Climate Transition ◽  
The North Pacific

Deep‐Water Formation in the North Pacific During the Late Miocene Global Cooling

2021 ◽  
Vol 36 (2) ◽  
Author(s):  
Lina Zhai ◽  
Shiming Wan ◽  
Christophe Colin ◽  
Debo Zhao ◽  
Yuntao Ye ◽  
...  
Keyword(s):  
Deep Water ◽  
Late Miocene ◽  
North Pacific ◽  
Deep Water Formation ◽  
The North ◽  
Global Cooling ◽  
Water Formation ◽  
The North Pacific

scholarly journals The global ocean circulation on a retrograde rotating earth

2011 ◽  
Vol 7 (2) ◽  
pp. 487-499 ◽  
Author(s):  
V. Kamphuis ◽  
S. E. Huisman ◽  
H. A. Dijkstra
Keyword(s):  
Ocean Circulation ◽  
Deep Water ◽  
North Pacific ◽  
Global Ocean ◽  
Freshwater Flux ◽  
Deep Water Formation ◽  
The North ◽  
Water Formation ◽  
Global Ocean Circulation ◽  
The North Pacific

Abstract. To understand the three-dimensional ocean circulation patterns that have occurred in past continental geometries, it is crucial to study the role of the present-day continental geometry and surface (wind stress and buoyancy) forcing on the present-day global ocean circulation. This circulation, often referred to as the Conveyor state, is characterised by an Atlantic Meridional Overturning Circulation (MOC) with a deep water formation at northern latitudes and the absence of such a deep water formation in the North Pacific. This MOC asymmetry is often attributed to the difference in surface freshwater flux: the Atlantic as a whole is a basin with net evaporation, while the Pacific receives net precipitation. This issue is revisited in this paper by considering the global ocean circulation on a retrograde rotating earth, computing an equilibrium state of the coupled atmosphere-ocean-land surface-sea ice model CCSM3. The Atlantic-Pacific asymmetry in surface freshwater flux is indeed reversed, but the ocean circulation pattern is not an Inverse Conveyor state (with deep water formation in the North Pacific) as there is relatively weak but intermittently strong deep water formation in the North Atlantic. Using a fully-implicit, global ocean-only model the stability properties of the Atlantic MOC on a retrograde rotating earth are also investigated, showing a similar regime of multiple equilibria as in the present-day case. These results indicate that the present-day asymmetry in surface freshwater flux is not the most important factor setting the Atlantic-Pacific salinity difference and, thereby, the asymmetry in the global MOC.

scholarly journals Does Net E − P Set a Preference for North Atlantic Sinking?

2012 ◽  
Vol 42 (11) ◽  
pp. 1781-1792 ◽  
Author(s):  
Selma E. Huisman ◽  
Henk A. Dijkstra ◽  
A. S. von der Heydt ◽  
W. P. M. de Ruijter
Keyword(s):  
North Atlantic ◽  
Deep Water ◽  
North Pacific ◽  
Multiple Equilibria ◽  
Meridional Overturning Circulation ◽  
Global Ocean ◽  
Overturning Circulation ◽  
The North ◽  
Meridional Overturning ◽  
The North Pacific

Abstract The present-day global meridional overturning circulation (MOC) with formation of North Atlantic Deep Water (NADW) and the absence of a deep-water formation in the North Pacific is often considered to be caused by the fact that the North Pacific basin is a net precipitative, while the North Atlantic is a net evaporative basin. In this paper, the authors study the effect of asymmetries in continent geometry and freshwater fluxes on the MOC both in an idealized two-dimensional model and in a global ocean model. This study approaches the problem from a multiple equilibria perspective, where asymmetries in external factors constrain the existence of steady MOC patterns. Both this multiple equilibria perspective and the fact that a realistic global geometry is used add new aspects to the problem. In the global model, it is shown that the Atlantic forced by net precipitation can have a meridional overturning circulation with northern sinking and a sea surface salinity that resembles the present-day salinity field. The model results are suggestive of the importance of factors other than the freshwater flux asymmetries, in particular continental asymmetries, in producing the meridional overturning asymmetry.

scholarly journals Deep water formation in the North Pacific and deglacial CO2rise

2014 ◽  
Vol 29 (6) ◽  
pp. 645-667 ◽  
Author(s):  
James W. B. Rae ◽  
Michael Sarnthein ◽  
Gavin L. Foster ◽  
Andy Ridgwell ◽  
Pieter M. Grootes ◽  
...  
Keyword(s):  
Deep Water ◽  
North Pacific ◽  
Deep Water Formation ◽  
The North ◽  
Water Formation ◽  
The North Pacific

Simulation of the 1976/77 Climate Transition over the North Pacific: Sensitivity to Tropical Forcing

2006 ◽  
Vol 19 (23) ◽  
pp. 6170-6180 ◽  
Author(s):  
Clara Deser ◽  
Adam S. Phillips
Keyword(s):  
Indian Ocean ◽  
North Pacific ◽  
Equatorial Pacific ◽  
Ensemble Average ◽  
Aleutian Low ◽  
The North ◽  
Tropical Ssts ◽  
Climate Transition ◽  
Western Half ◽  
The North Pacific

Abstract This study examines the contribution of tropical sea surface temperature (SST) forcing to the 1976/77 climate transition of the winter atmospheric circulation over the North Pacific using a combined observational and modeling approach. The National Center for Atmospheric Research (NCAR) Community Atmospheric Model version 3 (CAM3) simulates approximately 75% of the observed 4-hPa deepening of the wintertime Aleutian low from 1950–76 to 1977–2000 when forced with the observed evolution of tropical SSTs in a 10-member ensemble average. This response is driven by precipitation increases over the western half of the equatorial Pacific Ocean. In contrast, the NCAR Community Climate Model version 3 (CCM3), the predecessor to CAM3, simulates no significant change in the strength of the Aleutian low when forced with the same tropical SSTs in a 12-member ensemble average. The lack of response in CCM3 is traced to an erroneously large precipitation increase over the tropical Indian Ocean whose dynamical impact is to weaken the Aleutian low; this, when combined with the response to rainfall increases over the western and central equatorial Pacific, results in near-zero net change in the strength of the Aleutian low. The observed distribution of tropical precipitation anomalies associated with the 1976/77 transition, estimated from a combination of direct measurements at land stations and indirect information from surface marine cloudiness and wind divergence fields, supports the models’ simulated rainfall increases over the western half of the Pacific but not the magnitude of CCM3’s rainfall increase over the Indian Ocean.

Was deep water formed in the North Pacific during the Late Quaternary? Cadmium evidence from the Northwest Pacific

1994 ◽  
Vol 124 (1-4) ◽  
pp. 185-194 ◽  
Author(s):  
N. Ohkouchi ◽  
H. Kawahata ◽  
M. Murayama ◽  
M. Okada ◽  
T. Nakamura ◽  
...  
Keyword(s):  
Deep Water ◽  
North Pacific ◽  
Late Quaternary ◽  
Northwest Pacific ◽  
The North ◽  
The North Pacific
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