Eastern Pacific Pleistocene Alkenone Data and SST Reconstruction Liu, Z.; Herbert, T.D. Liu, Z. Herbert, T.D. Sea Surface Temperature Reconstruction earth science/paleoclimate/paleoceanography (depth,null,null,centimeter,null,paleoceanography,composited,null,N,null) earth science/paleoclimate/paleoceanography (age,null,null,radiocarbon year before present,null,paleoceanography,null,null,N,null) earth science/paleoclimate/climate reconstructions|paleoceanography (sea surface temperature,alkenone unsaturation index,null,degree Celsius,null,climate reconstructions|paleoceanography,null,null,N,null) earth science/paleoclimate/paleoceanography (C37 alkenone,null,null,nanomole per gram,null,paleoceanography,null,null,N,null) earth science/paleoclimate/paleoceanography (depth,null,null,centimeter,null,paleoceanography,null,null,N,null) earth science/paleoclimate/paleocean earth science/paleoclimate/paleocean earth science/paleoclimate/paleocean earth science/paleoclimate/paleocean (ODP 846>LATITUDE -3.095>LONGITUDE -90.81833) Many records of tropical sea surface temperature and marine productivity exhibit cycles of 23 kyr (orbital precession) and 100 kyr during the past 0.5Myr, whereas high-latitude sea surface temperature records display much more pronounced obliquity cycles at a period of about 41 kyr. Little is known, however, about tropical climate variability before the mid-Pleistocene transition about 900 kyr ago, which marks the change from a climate dominated by 41-kyr cycles (when ice-age cycles and high-latitude sea surface temperature variations were dictated by changes in the Earth?s obliquity) to the more recent 100-kyr cycles of ice ages. Here we analyse alkenones from marine sediments in the eastern equatorial Pacific Ocean to reconstruct sea surface temperatures and marine productivity over the past 1.8Myr. We find that both records are dominated by the 41-kyr obliquity cycles between 1.8 and 1.2Myr ago, with a relatively small contribution from orbital precession, and that early Pleistocene sea surface temperatures varied in the opposite sense to local annual insolation in the eastern equatorial Pacific Ocean. We conclude that during the early Pleistocene epoch, climate variability at our study site must have been determined by high-latitude processes that were driven by orbital obliquity forcing. NCDC-Paleoclimatology https://www.ncdc.noaa.gov/data-access/paleoclimatology-data - Bauer Bruce Investigator : Liu, Z. Investigator : Herbert, T.D. 2004-07-01 ONLINE Files online, ASCII https://www.ncdc.noaa.gov/paleo/study/2624 https://www1.ncdc.noaa.gov/pub/data/paleo/contributions_by_author/liu2004 https://www1.ncdc.noaa.gov/pub/data/paleo/paleocean/sediment_files/complete/odp846-l-tab.txt https://www1.ncdc.noaa.gov/pub/data/paleo/contributions_by_author/liu2004 https://www1.ncdc.noaa.gov/pub/data/paleo/paleocean/sediment_files/complete/odp846-l-tab.txt English https://www.ncdc.noaa.gov/paleo/study/2624 https://www1.ncdc.noaa.gov/pub/data/paleo/contributions_by_author/liu2004 https://www1.ncdc.noaa.gov/pub/data/paleo/paleocean/sediment_files/complete/odp846-l-tab.txt Liu, Z. and T.D. Herbert2004High-latitude influence on the eastern equatorial Pacific climate in the early Pleistocene epochNature10.1038/nature02338 START YEAR: 1833700 14C yr BP * END YEAR: 4000 14C yr BP -90.81833 -3.095 -90.81833 -3.095