title: Extra-long interglacial in Northern Hemisphere during MISs 15-13 arising from limited extent of Arctic ice sheets in glacial MIS 14.
abstract: Knowledge of the behavior of Northern Hemisphere (NH) ice sheets over the past million years is crucial for understanding the role of orbitally driven insolation changes on glacial/interglacial cycles. Here, based on the demonstrable link between changes in Chinese loess grain-size and NH ice-sheet extent, we use loess grain-size records to confirm that northern ice-sheets were restricted during marine oxygen isotope stage (MIS) 14. Thus, an unusually long NH interglacial climate of over 100 kyr persisted during MISs 15-13, much longer than expected from marine oxygen isotope records. Taking a global view of the paleoclimate records, MIS 14 inception seems to be a response to changes in Antarctic ice-sheets rather than to NH cooling. Orbital configuration in the two Polar regions shows that the onset of MIS 14 was forced by austral insolation changes, rather than by boreal summer insolation, as Milankovitch theory proposes. Our analysis of MIS 14 raises the possibility that southern insolation forcing may have played an important role in the inception of several other glacials. We suggest that the extra-long NH interglacial climate during MISs 15-13 provided favorable conditions for the second major dispersal episode of African hominins into Eurasia.
authors.affiliation: Key Laboratory of Cenozoic Geology and Environment, Institute of Geology and Geophysics, Chinese Academy of Sciences, P.O. Box 9825, Beijing 100029, China.
authors.forename: Qingzhen
authors.initials: Q
authors.lastname: Hao
authors.affiliation: Key Laboratory of Cenozoic Geology and Environment, Institute of Geology and Geophysics, Chinese Academy of Sciences, P.O. Box 9825, Beijing 100029, China.
authors.forename: Luo
authors.initials: L
authors.lastname: Wang
authors.affiliation: School of Environmental Sciences, University of Liverpool, Liverpool L69 7ZT, UK.
authors.forename: Frank
authors.initials: F
authors.lastname: Oldfield
authors.affiliation: Key Laboratory of Cenozoic Geology and Environment, Institute of Geology and Geophysics, Chinese Academy of Sciences, P.O. Box 9825, Beijing 100029, China.
authors.forename: Zhengtang
authors.initials: Z
authors.lastname: Guo
mesh_terms: D000864:Antarctic Regions; D001110:Arctic Regions; D001272:Atmosphere / Q000032:analysis*; D002980:Climate; D046448:Ice Cover / Q000737:chemistry*; D010100:Oxygen / Q000737:chemistry; D010103:Oxygen Isotopes / Q000737:chemistry*; D012621:Seasons
chemical_list: D010103:Oxygen Isotopes; D010100:Oxygen