Sea surface temperatures of southern midlatitudes 0-160 kyr BP

Publication Type  Journal Article
Year of Publication  2006
Authors  Pahnke, K.; Sachs, J. P.
Journal Title  Paleoceanography
Volume  21
Issue  2
Pages  -
Journal Date  Apr 13
ISBN Number  0883-8305
Accession Number  ISI:000237284700001
Key Words  glacial-interglacial changes; alkenone paleotemperature method; northern-hemisphere climate; eastern new-zealand; late quaternary; chatham rise; equatorial pacific; subtropical front; arabian sea; ice core

[1] Late Quaternary climate fluctuated between extremes of glaciations, lasting similar to 90 kyr on average, and interglacial episodes, lasting similar to 10 kyr. Still largely unknown are the spatial and temporal evolution of these global climate states, with vigorous debate still underway on the mechanisms responsible for glacial inceptions and terminations. Though it is widely believed that the Southern Hemisphere oceans play a central role in global climate changes, few paleoclimate records exist from there. Here we present three new alkenone-derived SST records from the midlatitude Southern Hemisphere spanning the last 160 kyr, a full glacial-interglacial cycle. Our subtropical SST records from the last glacial period are characterized by ( 1) warming 47 - 23 kyr B. P., when high latitudes in both hemispheres cooled, and ( 2) milder temperatures during the penultimate glacial period than during the last glacial interval. These SST features are found to be of tropical- to subtropical-wide extent, implying increased thermal gradients at times of high-latitude ice sheet growth. This has implications for the vigor of atmospheric and upper ocean circulation and the transport of heat and moisture to the poles that may have been instrumental in the growth and maintenance of polar ice sheets during glacial periods.


039EMTimes Cited:7Cited References Count:140

URL  <Go to ISI>://000237284700001
DOI  Doi 10.1029/2005pa001191