Objectif Understanding past climate change is crucially dependent on understanding oceanic and atmospheric circulation. The atmospheric contribution to paleoclimate is poorly constrained, especially on long (orbital) timescales that might provide meaningful information about the forcing mechanisms of major atmospheric components such as the monsoons. Aeolian dust preserved in deep-sea sediments provides an excellent means of determining past variations in continental paleoclimate and atmospheric circulation. Previous studies have focused mainly on sedimentologically determined variations of clay and quartz concentrations in aeolian dust. Direct comparison of dust records among different ocean cores and between the North Pacific Ocean and the Asian continent is hampered by poor age control and by poor data resolution from marine cores. Sediment magnetic parameters can efficiently provide high-resolution data for reconstructing paleoclimatic fluctuations. This project aims to detect systematic spatial-temporal variations in magnetic parameters as proxies of the Asian aeolian dust flux recorded in North Pacific marine sediments along a downwind longitudinal transect over the last several million years. Age models will be determined by a combination of relative paleointensity, oxygen isotope and paleomagnetic reversal stratigraphies. Paleoclimatically controlled variations in grain size and concentration of magnetite, hematite and goethite will be quantified and interpreted along with constraints from non-magnetic parameters (e.g. oxygen isotopes, Ti/Al ratios). We aim to detect how terrigenous dust flux is controlled at the full range of orbital periods. In turn, this will provide important constraints on the forcing mechanisms that drive atmospheric circulation and the Asian Monsoon. Champ scientifique natural sciencesearth and related environmental sciencespalaeontologypaleoclimatologyagricultural sciencesagriculture, forestry, and fisheriesagriculturegrains and oilseedsnatural sciencesearth and related environmental sciencesatmospheric sciencesmeteorologyatmospheric circulationnatural sciencesearth and related environmental sciencesatmospheric sciencesclimatologyclimatic changes Mots‑clés North Pacific Rock magnetism aeolian dust magnetic mineralogy marine sediment paleoclimate relative paleointensity Programme(s) FP6-MOBILITY - Human resources and Mobility in the specific programme for research, technological development and demonstration "Structuring the European Research Area" under the Sixth Framework Programme 2002-2006 Thème(s) MOBILITY-2.3 - Marie Curie Incoming International Fellowships (IIF) Appel à propositions FP6-2002-MOBILITY-7 Voir d’autres projets de cet appel Régime de financement IIF - Marie Curie actions-Incoming International Fellowships Coordinateur UNIVERSITY OF SOUTHAMPTON Contribution de l’UE Aucune donnée Adresse Highfield SOUTHAMPTON Royaume-Uni Voir sur la carte Liens Site web Opens in new window Coût total Aucune donnée
