|
|
|
|
|
| Xu, Jian; Kuhnt, Wolfgang; Holbourn, Ann; Regenberg, Marcus; Andersen, Nils. |
| We measured oxygen isotopes and Mg/Ca ratios in the surface-dwelling planktonic foraminifer Globigerinoides ruber (white s.s.) and the thermocline dweller Pulleniatina obliquiloculata to investigate upper ocean spatial variability in the Indo-Pacific Warm Pool (IPWP). We focused on three critical time intervals: the Last Glacial Maximum (LGM; 18-21.5 ka), the early Holocene (8-9 ka), and the late Holocene (0-2 ka). Our records from 24 stations in the South China Sea, Timor Sea, Indonesian seas, and western Pacific indicate overall dry and cool conditions in the IPWP during the LGM with a low thermal gradient between surface and thermocline waters. During the early Holocene, sea surface temperatures increased by similar to 3 degrees C over the entire... |
| Tipo: Text |
|
| Ano: 2010 |
URL: https://archimer.ifremer.fr/doc/00230/34131/33063.pdf |
| |
|
|
| Kuhnt, Wolfgang; Holbourn, Ann; Xu, Jian; Opdyke, Bradley; De Deckker, Patrick; Roehl, Ursula; Mudelsee, Manfred. |
| The evolution of the Australian monsoon in relation to high-latitude temperature fluctuations over the last termination remains highly enigmatic. Here we integrate high-resolution riverine runoff and dust proxy data from X-ray fluorescence scanner measurements in four well-dated sediment cores, forming a NE-SW transect across the Timor Sea. Our records reveal that the development of the Australian monsoon closely followed the deglacial warming history of Antarctica. A minimum in riverine runoff documents dry conditions throughout the region during the Antarctic Cold Reversal (15-12.9 ka). Massive intensification of the monsoon coincided with Southern Hemisphere warming and intensified greenhouse forcing over Australia during the atmospheric CO2 rise at... |
| Tipo: Text |
|
| Ano: 2015 |
URL: https://archimer.ifremer.fr/doc/00352/46296/45939.pdf |
| |
|
|
| Fraser, Nicholas; Kuhnt, Wolfgang; Holbourn, Ann; Bolliet, Timothe; Andersen, Nils; Blanz, Thomas; Beaufort, Luc. |
| Proxy records of hydrologic variability in the West Pacific Warm Pool (WPWP) have revealed wide-scale changes in past convective activity in response to orbital and suborbital climate forcings. However, attributing proxy responses to regional changes in WPWP hydrology versus local variations in precipitation requires independent records linking the terrestrial and marine realms. We present high-resolution stable isotope, U-37(K) sea surface temperature, X-ray fluorescence (XRF) core scanning, and coccolithophore-derived paleoproductivity records covering the past 120ka from International Marine Global Change (IMAGES) Program Core MD06-3075 (6 degrees 29N, 125 degrees 50E, water depth 1878m), situated in the Davao Gulf on the southern side of Mindanao.... |
| Tipo: Text |
Palavras-chave: Intertropical Convergence Zone; West Pacific Warm Pool; Walker circulation; Seawater 18O; X-ray fluorescence. |
| Ano: 2014 |
URL: https://archimer.ifremer.fr/doc/00289/40057/39357.pdf |
| |
|
|
| Zuraida, Rina; Holbourn, Ann; Nuernberg, Dirk; Kuhnt, Wolfgang; Duerkop, Anke; Erichsen, A.. |
| We present sea surface and upper thermocline temperature records (60-100 year temporal resolution) spanning marine isotope stage 3 (similar to 24-62 ka B. P.) from International Marine Global Change Study core MD01-2378 (121 degrees 47.27'E and 13 degrees 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 delta O-18(seawater) (P. obliquiloculata record) during Heinrich events 3, 4, and 5 reflect weakening of... |
| Tipo: Text |
|
| Ano: 2009 |
URL: https://archimer.ifremer.fr/doc/00218/32940/31434.pdf |
| |
|
|
| Xu, Jian; Kuhnt, Wolfgang; Holbourn, Ann; Andersen, Nils; Bartoli, Gretta. |
| We use a multiproxy approach to monitor changes in the vertical profile of the Indonesian Throughflow as well as monsoonal wind and precipitation patterns in the Timor Sea on glacial-interglacial, precessional, and suborbital timescales. We focus on an interval of extreme climate change and sea level variation: marine isotope (MIS) 6 to MIS 5e. Paleoproductivity fluctuations in the Timor Sea follow a precessional beat related to the intensity of the Australian (NW) monsoon. Paired Mg/Ca and delta(18)O measurements of surface- and thermocline-dwelling planktonic foraminifers ( G. ruber and P. obliquiloculata) indicate an increase of > 4 degrees C in both surface and thermocline water temperatures during Termination II. Tropical sea surface temperature... |
| Tipo: Text |
Palavras-chave: Vertical profile; Indonesian Throughflow (ITF); Termination II. |
| Ano: 2006 |
URL: https://archimer.ifremer.fr/doc/00234/34512/33420.pdf |
| |
|
|
| Kissel, Catherine; Laj, Carlo; Kienast, Markus; Bolliet, Timothe; Holbourn, Ann; Hill, Paul; Kuhnt, Wolfgang; Braconnot, Pascale. |
| Magnetic and grain size properties of a sediment core located in the western equatorial Pacific, off the southeastern tip of the Philippine island of Mindanao, are presented in an effort to reconstruct past changes in the East Asian Monsoon and deep ocean circulation during the last 160 kyrs. The sedimentary concentration of magnetic particles, interpreted to reflect past changes in runoff from Mindanao, varies almost in antiphase with Northern Hemisphere insolation. This suggests that precipitation was lower in the western equatorial Pacific region during boreal insolation maxima and thus corroborates model results showing opposing trends in precipitation between land and the marine realm there. Variations in the grain size distribution of the inorganic... |
| Tipo: Text |
Palavras-chave: North atlantic; Grain size; Water; Core; Mindanao; Paleoceanography; Susceptibility; Anisotropy; Remanence; Iceland. |
| Ano: 2010 |
URL: https://archimer.ifremer.fr/doc/00207/31854/30262.pdf |
| |
|
|
| Sadekov, Aleksey; Eggins, Stephen M.; De Deckker, Patrick; Ninnemann, Ulysses; Kuhnt, Wolfgang; Bassinot, Franck. |
| Laser-ablation inductively coupled plasma-mass spectrometry microanalyses of Mg/Ca across individual final chambers of three planktonic foraminifera species, Globigerinoides ruber, G. sacculifer, and Pulleniatina obliquiloculata, reveal significant interspecies differences in test Mg concentrations. Whereas these three species have similar Mg/Ca values at low sea surface temperatures (similar to 22 degrees C), they diverge markedly at high sea surface temperatures (similar to 29 degrees C). Explanations for these differences in species Mg/Ca values based on detailed comparison of species intratest Mg/Ca distributions suggest that compositional variability within tests cannot account for the observed deviation of species Mg/Ca values in warm-water... |
| Tipo: Text |
|
| Ano: 2009 |
URL: https://archimer.ifremer.fr/doc/00218/32934/31448.pdf |
| |
|
|
| Bolliet, Timothe; Holbourn, Ann; Kuhnt, Wolfgang; Laj, Carlo; Kissel, Catherine; Beaufort, Luc; Kienast, Markus; Andersen, Nils; Garbe-schoenberg, Dieter. |
| We present sea surface, upper thermocline, and benthic delta O-18 data, as well as temperature and paleoproductivity proxy data, from the International Marine Global Change Study Program (IMAGES) Core MD06-3067 (6 degrees 31' N, 126 degrees 30' E, 1575 m water depth), located in the western equatorial Pacific Ocean within the flow path of the Mindanao Current. Our records reveal considerable glacial-interglacial and suborbital variability in the Mindanao Dome upwelling over the last 160 kyr. Dome activity generally intensified during glacial intervals resulting in cooler thermocline waters, whereas it substantially declined during interglacials, in particular in the early Holocene and early marine oxygen isotope stage (MIS) 5e, when upwelling waters did... |
| Tipo: Text |
Palavras-chave: Mindanao Dome; East Asian monsoon; Oceanic circulation. |
| Ano: 2011 |
URL: https://archimer.ifremer.fr/doc/00213/32472/30924.pdf |
| |
|
|
| Bian, Yeping; Jian, Zhimin; Weng, Chengyu; Kuhnt, Wolfgang; Bolliet, Timothe; Holbourn, Ann. |
| A palynological analysis of a marine sediment core in the southern Philippines, provides a detailed regional vegetation and climate history for the West Pacific Warm Pool (WPWP) since the Last Glacial Maximum (LGM). Chronology was determined by a detailed oxygen isotope record. A higher representation of pollen from tropical upper montane rainforest during the LGM indicate that this forest type moved down along elevation, probabaly due to the lowered temperature. During the last deglaciation and the early Holocene, mangroves were more expanded and tropical mid and upper montane rainforests were restricted, suggesting a rising sea-level and temperature increase. Herbaceous pollen and pteridophyte spore records indicate a much drier condition during the LGM... |
| Tipo: Text |
Palavras-chave: Last Glacial Maximum; Tropical rainforests; Palynological analyses; Sea-level change; River discharge. |
| Ano: 2011 |
URL: https://archimer.ifremer.fr/doc/00213/32468/30921.pdf |
| |
|
|
|
