A5034060391- Geology and Paleoclimatology Research
- Geological formations and processes
- Geological and Geophysical Studies
- Geological Studies and Exploration
- Hydrocarbon exploration and reservoir analysis
- Methane Hydrates and Related Phenomena
- Isotope Analysis in Ecology
- Marine and environmental studies
- Paleontology and Stratigraphy of Fossils
- Marine Biology and Ecology Research
- Marine and coastal ecosystems
- Geochemistry and Elemental Analysis
- Geomagnetism and Paleomagnetism Studies
- Pleistocene-Era Hominins and Archaeology
- Geochemistry and Geologic Mapping
- Environmental and Cultural Studies in Latin America and Beyond
- Maritime and Coastal Archaeology
- Tree-ring climate responses
- Calcium Carbonate Crystallization and Inhibition
- Geological Formations and Processes Exploration
- Oceanographic and Atmospheric Processes
- Geophysics and Gravity Measurements
- Climate variability and models
- Arctic and Antarctic ice dynamics
- Groundwater and Isotope Geochemistry
University of California, Santa Barbara
2012-2023
GEOMAR Helmholtz Centre for Ocean Research Kiel
2007
Kiel University
2007
University of Bremen
2004-2006
Deutsche Forschungsgemeinschaft
2005
University of Tübingen
2002-2003
Leibniz Institute for Baltic Sea Research
2002-2003
A detailed reconstruction of West African monsoon hydrology over the past 155,000 years suggests a close linkage to northern high-latitude climate oscillations. Ba/Ca ratio and oxygen isotope composition planktonic foraminifera in marine sediment core from Gulf Guinea, eastern equatorial Atlantic (EEA), reveal centennial-scale variations riverine freshwater input that are synchronous with stadials interstadials penultimate interglacial last deglaciation. EEA Mg/Ca-based sea surface...
Abstract Rapid changes in ocean circulation and climate have been observed marine-sediment ice cores over the last glacial period deglaciation, highlighting non-linear character of system underlining possibility rapid shifts response to anthropogenic greenhouse gas forcing. To date, these are still not fully explained. One obstacle hindering progress our understanding interactions between past is difficulty accurately dating marine cores. Here, we present a set 92 sediment from Atlantic...
Thirteen laboratories from the USA and Europe participated in an intercomparison study of Mg/Ca Sr/Ca measurements foraminifera. The included five planktonic species surface sediments different geographical regions water depths. Each followed their own cleaning analytical procedures had no specific information about samples. Analysis solutions known ratios showed that intralaboratory instrumental precision is better than 0.5% for both measurements, regardless whether ICP‐OES or ICP‐MS used....
[1] In this study we utilize two organic geochemical proxies, the U37k′ index and TEX86, to examine past sea surface temperatures (SST) from a site located near Nile River Delta in eastern Mediterranean (EM) Sea. The TEX86 records generally are agreement indicate SST ranges of 14°C–26°C 14°C–28°C, respectively, during last 27 cal ka. During Holocene, TEX86-based estimates usually higher than U37k′-based estimates, which is likely due seasonal differences between timing haptophyte...
Abstract African monsoon precipitation experienced a dramatic change in the course of Holocene. The pace with which shifted from strong early to middle weak late Holocene is critical for our understanding climate dynamics, hydroclimate‐vegetation interaction, and shifts prehistoric human settlements, yet it controversially debated. On basis planktonic foraminiferal Ba/Ca time series eastern Mediterranean Sea, here we present proxy record Nile River runoff that provides spatially integrated...
Research Article| December 01, 2005 Holocene African droughts relate to eastern equatorial Atlantic cooling Syee Weldeab; Weldeab 1Deutsche Forschungsgemeinschaft (DFG) Center Ocean Margins, Bremen University, Leobener Strasse, 28359 Bremen, Germany Search for other works by this author on: GSW Google Scholar Ralph R. Schneider; Schneider 2Institut für Geowissenschaften, Universität Kiel, Ludewig-Meyn-Strasse 10, 24118 Martin Kölling; Kölling 3Deutsche Gerold Wefer Geology (2005) 33 (12):...
Sea surface temperature (SST) for the central equatorial Indian Ocean, has been reconstructed over last ∼137 kyr, from Mg/Ca of planktonic foraminiferal species Globigerinoides ruber . According to our record Ocean SST was ∼2.1°C colder during glacial maximum as compared present times. The data further shows that comparatively warmer isotopic stage 5e than at (∼29.9 vs ∼28.5°C). Comparison with Antarctic δD and Greenland δ 18 O records, major high‐latitude cooling/warming events are also in...
A Holocene Gulf of Guinea record riverine runoff, based on Ba/Ca in tests a shallow‐dwelling planktic foraminifer, and sea surface temperature (SST), Mg/Ca, reveals centennial‐scale instabilities West African monsoon (WAM) precipitation eastern equatorial Atlantic (EEA) thermal conditions. The long‐term climate trend is characterized by warm wet early‐mid gradual drying cooling during the late Holocene. Superimposed this are numerous centennial scale drops greatest declines early were...
Abstract. We established a multi-proxy time series comprising analyses of major elements in bulk sediments, Sr and Nd isotopes, grain size terrigenous fraction, δ18O δ13C tests Neogloboquadrina pachyderma (sinistral) from marine sediment sequence recovered off the Orange River. The records reveal coherent patterns variability that reflect changes wind strength, precipitation over river catchments, upwelling cold nutrient-rich coastal waters western South Africa. wettest episode Holocene...
The stability of widespread methane hydrates in shallow subsurface sediments the marine continental margins is sensitive to temperature increases experienced by upper intermediate waters. Destabilization and ensuing release would produce climatic feedbacks amplifying accelerating global warming. Hence, improved assessment ongoing water warming crucially important, especially that resulting from a weakening Atlantic meridional overturning circulation (AMOC). Our study provides an independent...
Indian Summer Monsoon (ISM) precipitation is the main determinant of livelihood in a densely populated world region. The interannual variability ISM influenced by several modes climate variability, including anomalous seasonal sea surface temperature (SST) gradient reversals between eastern, western, and northeastern Ocean. With global warming, frequency zonal meridional Ocean's SST changes projected to increase but its impact on debated. Here we present 25,000-year proxy record inferred...
Abstract We present a benthic foraminiferal multiproxy record of eastern equatorial Atlantic (EEA) middepth water (1295 m) covering the last deglacial. show that EEA temperatures were elevated by 3.9 ± 0.5°C and 5.2 1.2°C during Heinrich event 1 (H1) Younger Dryas (YD), respectively. The radiocarbon content H1 YD is relatively low comparable to values pre‐H1 episode Bølling‐Allerød, A transient Earth system model simulation, which mimics observed deglacial Meridional Overturning Circulation...