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Middle Miocene Southern Ocean Cooling and Antarctic Cryosphere Expansion.
- Source :
-
Science . 9/17/2004, Vol. 305 Issue 5691, p1766-1770. 5p. - Publication Year :
- 2004
-
Abstract
- Magnesium/calcium data from Southern Ocean planktonic foraminifera demonstrate that high-latitude (∼55°S) southwest Pacific sea surface temperatures (SSTs) cooled 6° to 7°C during the middle Miocene climate transition (14.2 to 13.8 million years ago). Stepwise surface cooling is paced by eccentricity forcing and precedes Antarctic cryosphere expansion by ∼60 thousand years, suggesting the involvement of additional feedbacks during this interval of inferred low-atmospheric partial pressure of CO[sub 2] (pCO[sub 2]). Comparing SSTs and global carbon cycling proxies challenges the notion that episodic pCO[sub 2] drawdown drove this major Cenozoic climate transition. SST, salinity, and ice-volume trends suggest instead that orbitally paced ocean circulation changes altered meridional heat/vapor transport, triggering ice growth and global cooling. [ABSTRACT FROM AUTHOR]
- Subjects :
- *OCEAN
*COOLING
*TEMPERATURE
*CARBON dioxide
*HEAT
*SALINITY
Subjects
Details
- Language :
- English
- ISSN :
- 00368075
- Volume :
- 305
- Issue :
- 5691
- Database :
- Academic Search Index
- Journal :
- Science
- Publication Type :
- Academic Journal
- Accession number :
- 14576452
- Full Text :
- https://doi.org/10.1126/science.1100061