@article {364,
	title = {Southward movement of the Pacific intertropical convergence zone AD 1400-1850},
	journal = {Nature Geoscience},
	volume = {2},
	year = {2009},
	note = {id: 847; 497LS Times Cited:5 Cited References Count:45Y},
	pages = {519-525},
	abstract = {Tropical rainfall patterns control the subsistence lifestyle of more than one billion people. Seasonal changes in these rainfall patterns are associated with changes in the position of the intertropical convergence zone, which is characterized by deep convection causing heavy rainfall near 10 degrees N in boreal summer and 3 degrees N in boreal winter. Dynamic controls on the position of the intertropical convergence zone are debated, but palaeoclimatic evidence from continental Asia, Africa and the Americas suggests that it has shifted substantially during the past millennium, reaching its southernmost position some time during the Little Ice Age (AD 1400-1850). However, without records from the meteorological core of the intertropical convergence zone in the Pacific Ocean, quantitative constraints on its position are lacking. Here we report microbiological, molecular and hydrogen isotopic evidence from lake sediments in the Northern Line Islands, Galapagos and Palau indicating that the Pacific intertropical convergence zone was south of its modern position for most of the past millennium, by as much as 500 km during the Little Ice Age. A colder Northern Hemisphere at that time, possibly resulting from lower solar irradiance, may have driven the intertropical convergence zone south. We conclude that small changes in Earth{\textquoteright}s radiation budget may profoundly affect tropical rainfall.},
	issn = {1752-0894},
	doi = {10.1038/Ngeo554},
	author = {Sachs, J. P. and Sachse, D. and Smittenberg, R. H. and Zhang, Z. H. and Battisti, D. S. and Golubic, S.}
}
@article {458,
	title = {Biomarker evidence for the co-occurrence of three races (A, B and L) of Botryococcus braunii in El Junco Lake, Galapagos},
	journal = {Organic Geochemistry},
	volume = {38},
	year = {2007},
	note = {id: 590; 218MC Times Cited:7 Cited References Count:72},
	pages = {1459-1478},
	abstract = {In spite of the fact that individual races of Botryococcus braunii are widely distributed in lakes, reports of the co-existence of different chemical races are rare. Here we report biomarker evidence for the co-occurrence of three different races of B. braunii (A, B and L) in the water column and sediments of El Junco Lake, a freshwater crater lake at 700 m elevation on San Cristobal Island, Galapagos. We also show the existence of lycopadienes and lycopatrienes in suspended particles and sediments. Biomarker indicators of the three races were: cis and trans C-25-C-31 n-alkadienes and a C-29 triene for race A, a series of C34H58 botryococcenes for race B, and a C40H78 hydrocarbon, trans, trans-lycopadiene accompanied by minor amounts of isomers for race L. Epoxides derived from n-alkadienes and trans, trans-lycopadiene, specific to races A and L respectively, were also detected. Several previously unreported lycopadienes and lycopatrienes were identified in both the water column and sediment, and are believed to represent by-products and intermediates, respectively, of trans, trans-lycopadiene synthesis. Botryococcene and lycopadiene concentrations reached 16.7 and 0.8 mg/g dry sediment in near-surface sediments, and varied over more than three orders of magnitude, while n-alkadienes were present in trace quantities. Pyrolysates from the kerogen fraction of sediment contained lycopadiene and alkadiene related lipids along with chemically resistant polymers of R braunii cell walls. Apparently n-alkadienes, botryococcenes and lycopadienes and -trienes can survive in oxic sediments for several decades, and the down core variation in these lipids likely reflects changes in lake hydrology, alternately favoring the bloom or near-extinction of R braunii race B. (C). 2007 Elsevier Ltd. All rights reserved.},
	issn = {0146-6380},
	doi = {10.1016/J.Orggeochem.2007.05.015},
	author = {Zhang, Z. H. and Metzger, P. and Sachs, J. P.}
}
@article {1892,
	title = {Cooling of Northwest Atlantic slope waters during the Holocene},
	journal = {Geophysical Research Letters},
	volume = {34},
	year = {2007},
	note = {136deTimes Cited:35
Cited References Count:33
},
	month = {Feb 10},
	abstract = {[1] Climate of the last 11,000 years, the Holocene, is usually described as warm and stable. Benchmark temperature records from central Greenland ice cores show none of the large, abrupt variations that characterized the prior 100,000 years of glacial climate. Nor do they show any substantial trend, indicating at most 1 degrees-3 degrees C of cooling. Here we show that the slope waters east of the United States and Canada cooled 4 degrees-10 degrees C during the Holocene. Declining insolation, increasing convection in the Labrador Sea, and equatorward shifting of the Gulf Stream path may have caused the cooling.},
	keywords = {circulation, deposition, ice, labrador sea, ocean, oscillation, sea-surface, stratigraphy, Temperature, variability},
	isbn = {0094-8276},
	doi = {10.1029/2006GL028495},
	author = {Sachs, J. P.}
}
@article {1930,
	title = {Sea surface temperatures of southern middle-latitudes 0-160 by BP},
	journal = {Paleoceanography},
	volume = {21},
	year = {2006},
	note = {id: 591},
	month = {2006},
	author = {Pahnke, K. and Sachs, J. P.}
}
@article {1988,
	title = {The 8200 year B. P. event in the slop water system, western sublpolar North Atlantic},
	journal = {Paleoceanography},
	volume = {20},
	year = {2005},
	note = {id: 1097},
	month = {2005},
	author = {Keigwin, L. D. and Sachs, J. P. and Rosenthal, Y. and Boyle, E. A.}
}
@article {625,
	title = {Increased productivity in the subantarctic ocean during Heinrich events},
	journal = {Nature},
	volume = {434},
	year = {2005},
	note = {Sachs, Julian PAnderson, Robert FengResearch Support, Non-U.S. Gov{\textquoteright}tResearch Support, U.S. Gov{\textquoteright}t, Non-P.H.S.England2005/04/29 09:00Nature. 2005 Apr 28;434(7037):1118-21.},
	month = {Apr 28},
	pages = {1118-21},
	abstract = {Massive iceberg discharges from the Northern Hemisphere ice sheets, {\textquoteright}Heinrich events{\textquoteright}, coincided with the coldest periods of the last ice age. There is widespread evidence for Heinrich events and their profound impact on the climate and circulation of the North Atlantic Ocean, but their influence beyond that region remains uncertain. Here we use a combination of molecular fingerprints of algal productivity and radioisotope tracers of sedimentation to document eight periods of increased productivity in the subpolar Southern Ocean during the past 70,000 years that occurred within 1,000-2,000 years of a Northern Hemisphere Heinrich event. We discuss possible causes for such a link, including increased supply of iron from upwelling and increased stratification during the growing season, which imply an alteration of the global ocean circulation during Heinrich events. The mechanisms linking North Atlantic iceberg discharges with subantarctic productivity remain unclear at this point. We suggest that understanding how the Southern Ocean was altered during these extreme climate perturbations is critical to understanding the role of the ocean in climate change.},
	issn = {0028-0836 (Linking)},
	doi = {10.1038/nature03544},
	author = {Sachs, J. P. and Anderson, R. F.}
}
@article {617,
	title = {A 1600-year history of the Labrador Current off Nova Scotia},
	journal = {Climate Dynamics},
	volume = {21},
	year = {2003},
	note = {698thTimes Cited:25Cited References Count:31},
	month = {Jul},
	pages = {53-62},
	abstract = {A multicore from Emerald Basin, on the continental margin off Nova Scotia, has a modern C-14 age at the top, and other C-14 dates indicate a linear sedimentation rate of similar to30 cm/ka to 1600 calendar years BP. This rate is great enough to record century-to-millennial scale changes in the surface and deep (similar to250 m) waters in the basin that are influenced by the Labrador Current. We applied five proxies for seawater temperature changes to the sediments of Emerald Basin, including the percent abundance and the oxygen isotope ratio (delta(18)O) of the polar planktonic foraminifer N. pachyderma (s.), the unsaturation ratio of alkenones (U-37(k{\textquoteright})) produced by prymnesiophyte phytoplankton, and the delta(18)O and Mg/Ca of benthic foraminifera. All five proxies indicate the ocean warmed suddenly sometime in the past 150 years or so. The exact timing of this event is uncertain because C-14 dating is inaccurate in recent centuries, but this abrupt warming probably correlates with widespread evidence for warming in the Arctic in the nineteenth century. Because the Canadian Archipelago is one of the two main sources for the Labrador Current, warming and melting of ice caps in that region may have affected Labrador Current properties. Before this recent warming, sea surface temperature was continually lower by 1-2 degreesC, and bottom water was colder by about 6 degreesC in Emerald Basin. These results suggest that there was no Medieval Warm Period in the coastal waters off Nova Scotia. Because there is also no evidence of medieval warming in the Canadian archipelago, it seems likely that coastal waters from Baffin Bay to at least as far south as Nova Scotia were continually cold for similar to1500 of the past 1600 years.},
	issn = {0930-7575},
	doi = {10.1007/s00382-003-0316-6},
	author = {Keigwin, L. D. and Sachs, J. P. and Rosenthal, Y.}
}
@article {949,
	title = {Thirty thousand year record of climate from the Galapagos Islands and links with high latitudes},
	journal = {EOS},
	volume = {82},
	year = {2001},
	note = {id: 255},
	abstract = {Fall Meeting Supplement F737},
	author = {Koutavas, A. and Lynch-Stieglitz, J. and Sachs, J. P. and Marchitto, T. M.}
}
