title: Paleoceanography. Antarctic role in Northern Hemisphere glaciation.
abstract: Earth's climate underwent a major transition from the warmth of the late Pliocene, when global surface temperatures were ~2° to 3°C higher than today, to extensive Northern Hemisphere glaciation (NHG) ~2.73 million years ago (Ma). We show that North Pacific deep waters were substantially colder (4°C) and probably fresher than the North Atlantic Deep Water before the intensification of NHG. At ~2.73 Ma, the Atlantic-Pacific temperature gradient was reduced to <1°C, suggesting the initiation of stronger heat transfer from the North Atlantic to the deep Pacific. We posit that increased glaciation of Antarctica, deduced from the 21 ± 10-meter sea-level fall from 3.15 to 2.75 Ma, and the development of a strong polar halocline fundamentally altered deep ocean circulation, which enhanced interhemispheric heat and salt transport, thereby contributing to NHG.
authors.affiliation: Department of Marine and Coastal Sciences, Rutgers University, 71 Dudley Road, New Brunswick, NJ 08901, USA. woodard@marine.rutgers.edu.
authors.forename: Stella C
authors.initials: SC
authors.lastname: Woodard
authors.affiliation: Department of Marine and Coastal Sciences, Rutgers University, 71 Dudley Road, New Brunswick, NJ 08901, USA. Department of Earth and Planetary Sciences, Rutgers University, 610 Taylor Road, Piscataway, NJ 08845, USA.
authors.forename: Yair
authors.initials: Y
authors.lastname: Rosenthal
authors.affiliation: Department of Earth and Planetary Sciences, Rutgers University, 610 Taylor Road, Piscataway, NJ 08845, USA.
authors.forename: Kenneth G
authors.initials: KG
authors.lastname: Miller
authors.affiliation: Department of Earth and Planetary Sciences, Rutgers University, 610 Taylor Road, Piscataway, NJ 08845, USA.
authors.forename: James D
authors.initials: JD
authors.lastname: Wright
authors.affiliation: Department of Earth and Planetary Sciences, Rutgers University, 610 Taylor Road, Piscataway, NJ 08845, USA.
authors.forename: Beverly K
authors.initials: BK
authors.lastname: Chiu
authors.affiliation: Department of Geology and Environmental Geosciences, Lafayette College, 730 High Street, Easton, PA 18042, USA.
authors.forename: Kira T
authors.initials: KT
authors.lastname: Lawrence
mesh_terms: D000864:Antarctic Regions; D057232:Global Warming; D006358:Hot Temperature; D046448:Ice Cover; D009792:Oceans and Seas