• Publications
  • Influence
Global temperature change
Comparison of measured sea surface temperatures in the Western Pacific with paleoclimate data suggests that this critical ocean region is approximately as warm now as at the Holocene maximum and within ≈1°C of the maximum temperature of the past million years. Expand
Reevaluation of the oxygen isotopic composition of planktonic foraminifera: Experimental results and revised paleotemperature equations
Cultured planktonic foraminifera, Orbulina universa (symbiotic) and Globigerina bulloides (nonsymbiotic), are used to reexamine temperature:δ18O relationships at 15°–25°C. Relationships for bothExpand
Controls on magnesium and strontium uptake in planktonic foraminifera determined by live culturing
Abstract Because strontium and magnesium occur in seawater with nearly constant ratios to calcium, variations in Sr/Ca and Mg/Ca in modern foraminifer shells are due to the influence of environmentalExpand
Core top calibration of Mg/Ca in tropical foraminifera: Refining paleotemperature estimation
[1] Optimal use of Mg/Ca as a paleotemperature proxy requires establishing calibrations for different species of foraminifera and quantifying the influence of dissolution. To achieve this goal, weExpand
Middle Miocene Southern Ocean Cooling and Antarctic Cryosphere Expansion
Comparing SSTs and global carbon cycling proxies challenges the notion that episodic pCO2 drawdown drove this major Cenozoic climate transition, and suggests instead that orbitally paced ocean circulation changes altered meridional heat/vapor transport, triggering ice growth and global cooling. Expand
Effect of seawater carbonate concentration on foraminiferal carbon and oxygen isotopes
Stable oxygen and carbon isotope measurements on biogenic calcite and aragonite have become standard tools for reconstructing past oceanographic and climatic change. In aquatic organisms, 18O/16OExpand
Final closure of Panama and the onset of northern hemisphere glaciation
The Greenland ice sheet is accepted as a key factor controlling the Quaternary “glacial scenario“. However, the origin and mechanisms of major Arctic glaciation starting at 3.15 Ma and culminating atExpand
Variability in the El Niño-Southern Oscillation Through a Glacial-Interglacial Cycle
Annual banded corals from Papua New Guinea are used to show that ENSO has existed for the past 130,000 years, operating even during “glacial” times of substantially reduced regional and global temperature and changed solar forcing, and it is found that during the 20th century ENGSO has been strong compared with E NSO of previous cool and warm times. Expand
Synchroneity of Tropical and High-Latitude Atlantic Temperatures over the Last Glacial Termination
A rapid southward shift in the atmospheric intertropical convergence zone could account for the synchroneity of tropical temperature, atmospheric methane, and high-latitude changes during the Younger Dryas. Expand
Links between salinity variation in the Caribbean and North Atlantic thermohaline circulation
Caribbean salinity oscillated between saltier conditions during the cold oxygen isotope stages 2, 4 and 6, and lower salinities during the warm stages 3 and 5, covarying with the strength of North Atlantic Deep Water formation, suggesting that the advection of salty tropical waters into the North Atlantic amplified thermohaline circulation and contributed to high-latitude warming. Expand