Effect of the deepening of the Tasman Gateway on the global ocean

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doi: 10.1029/2011PA002143
Author(s): Sijp, Willem P.; England, Matthew H.; Huber, Matthew
Author Affiliation(s): Primary:
University of New South Wales, Climate Change Research Centre, Sydney, N.S.W., Australia
Other:
Purdue University, United States
Volume Title: Paleoceanography
Source: Paleoceanography, 26(4). Publisher: American Geophysical Union, Washington, DC, United States. ISSN: 0883-8305 CODEN: POCGEP
Note: In English. 62 refs.; illus., incl. 2 tables
Summary: We examine the effect of the deepening of the Tasman Seaway at the end of the Eocene in a climate model with realistic late Eocene bathymetry and winds. For this, we have constructed an Eocene numerical model based on the University of Victoria climate model with wind forcing derived from a fully coupled Eocene simulation. The model climate state is characterized by an oceanic meridional overturning circulation (MOC) involving Southern Hemisphere sinking and a northward atmospheric moisture transport across the equator. The deepening of the Tasman Seaway in the presence of an open Drake Passage and the associated establishment of the Antarctic Circumpolar Current (ACC) have a limited climatic impact on Antarctica. Nonetheless, the Antarctic deep sinking regions cool sufficiently to lead to a global deep ocean cooling of 3°C. No initiation of Northern Component Water is found, indicating that this may require the development of a more mature ACC. Previous studies suggest that the Ross Sea gyre cools the east coast of Australia, and expected the deepening of the Tasman Seaway to lead to a warming east of Australia due to the introduction of warmer water from the Australo-Antarctic Gulf. We here find that this warming is limited to close to the Australian coast, and that widespread cooling prevails further off shore.
Year of Publication: 2011
Research Program: DSDP Deep Sea Drilling Project
IPOD International Phase of Ocean Drilling
Key Words: 07 Marine Geology and Oceanography; Antarctic Circumpolar Current; Atlantic Ocean; Atmospheric circulation; Cenozoic; Climate; Climate forcing; Currents; DSDP Site 336; DSDP Site 511; Deep Sea Drilling Project; Eocene; Global; Heat transfer; IPOD; Iceland-Faeroe Ridge; Leg 38; Leg 71; Meridional overturning circulation; North Atlantic; Northern Component Water; Numerical models; Ocean circulation; Ocean currents; Pacific Ocean; Paleo-oceanography; Paleobathymetry; Paleoclimatology; Paleogene; Ross Sea Gyre; Sea-surface temperature; Simulation; South Atlantic; South Pacific; Southwest Pacific; Tasman Basin; Tertiary; Thermocline; West Pacific; Winds; World ocean
Coordinates: S510017 S510017 W0465818 W0465818
N632103 N632104 W0074716 W0074717
Record ID: 2014039630
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