Description: We present a high-resolution (not, vert, similar 60-110 yr) multi-proxy record spanning Marine Isotope Stage 3 from IMAGES Core MD01-2378 (13°04.95'S and 121°47.27'E, 1783 m water depth), located in the Timor Sea, off NW Australia. Today, this area is influenced by the Intertropical Convergence Zone, which drives monsoonal winds during austral summer and by the main outflow of the Indonesian Throughflow, which represents a key component of the global thermohaline circulation system. Thus, this core is ideally situated to monitor the linkages between tropical and high latitude climate variability. Benthic d18O data (Planulina wuellerstorfi) clearly reflect Antarctic warm events (A1-A4) as recorded by the EPICA Byrd and Dronning Maud Land ice cores. This southern high latitude signal is transferred by deep and intermediate water masses flowing northward from the Southern Ocean into the Indian Ocean. Planktonic d18O shows closer affinity to northern high latitudes planktonic and ice core records, although only the longer-lasting Dansgaard-Oeschger warm events, 8, 12, 14, and 16-17 are clearly expressed in our record. This northern high latitude signal in the surface water is probably transmitted through atmospheric teleconnections and coupling of the Asian-Australian monsoon systems. Benthic foraminiferal census counts suggest a coupling of Antarctic cooling with carbon flux patterns in the Timor Sea. We relate increasing abundances of carbon-flux sensitive species at 38-45 ka to the northeastward migration of the West Australian Current frontal area. This water mass reorganization is also supported by concurrent decreases in Mg/Ca and planktonic d18O values (Globigerinoides ruber white).

Description: We present sea surface and upper thermocline temperature records (60-100 yr temporal resolution) spanning Marine Isotope Stage 3 (~24-62 kyr BP) from IMAGES Core MD01-2378 (121°47.27'E and 13°04.95'S; 1783 m water depth) located in the outflow area of the Indonesian Throughflow within the Timor Sea. Stable isotopes and Mg/Ca of the near surface dwelling planktonic foraminifer Globigerinoides ruber (white) and the upper thermocline dwelling Pulleniatina obliquiloculata reveal rapid changes in the thermal structure of the upper ocean during Heinrich Events. Thermocline warming and increased delta18Oseawater (P. obliquiloculata record) during Heinrich Events 3, 4, and 5 reflect weakening of the relatively cool and fresh thermocline flow and reduced export of less saline water from the North Pacific and Indonesian Seas to the tropical Indian Ocean. Three main factors influenced Indonesian Throughflow variability during Marine Isotope Stage 3: (1) global slow-down in thermohaline circulation during Heinrich Events triggered by northern hemisphere cooling; (2) increased freshwater export from the Java Sea into the Indonesian Throughflow controlled by rising sea level from ~60 to 47 ka and (3) insolation related changes in Australasian monsoon with associated migration of hydrological fronts between Indian Ocean and Indonesian Throughflow derived water masses at ~46-40 ka.

Description: Climatic conditions in the western Timor Sea and the adjacent northwestern part of Australia are reconstructed for the last 460 ka, based on geochemical and palynological proxy records of paleoproductivity and land vegetation (precipitation) from IMAGES Core MD01-2378. Reduced precipitation and elevated productivity characterize glacial stages, whereas enhanced precipitation and reduced productivity are typical of interglacial stages. A long-term reduction in precipitation over the last 320 ka occurred in two steps at approximately 300 ka and 180 ka BP that are clearly recognizable in the pollen record. Variations in paleoproductivity and paleoclimate in the Timor Sea and adjacent landmasses appear to be driven by similar mechanisms that are related to the precession-controlled Australian monsoon system.

Description: A high-resolution (~1-2 kyr) multiproxy record from the Timor Sea in the easternmost Indian Ocean (International Marine Global Change (IMAGES) Program Core MD01-2378, latitude 13°04.95'S, longitude 121°47.27'E, 1783 m water depth) closely tracks changes in intermediate water ventilation and paleoproductivity over the last 460 kyr within one of the main outflow passages of the Indonesian Throughflow. Spectral analysis of five different flux-based productivity proxies indicates spectral power concentrated in the 100 kyr (glacial-interglacial) and the 23 kyr and 19 kyr (precessional) periods. Paleoproductivity maxima lead ice volume (benthic delta18O) maxima by 20° to 40° (~1300 to 2600 years) at the precession band. The spectral differences in tropical paleoproductivity records from the Pacific and Indian oceans suggest that local processes (wind and circulation patterns driven by insolation) are dominant in driving productivity rather than large-scale tropical features. In the Timor Sea, productivity fluctuations over the last 460 kyr were strongly influenced by monsoonal wind patterns offshore NW Australia (23 and 19 kyr) and were also modulated by sea level-related variations in the intensity of the Indonesian Throughflow (100 kyr).