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.

A high-resolution mid-Pleistocene temperature record from Arctic Lake El'gygytgyn: a 50 kyr super interglacial from MIS 33 to MIS 31?

“…In light of our temperature reconstruction, however, it could be interpreted as a mechanism that can explain the warmth during MIS 32 (when SH insolation was high, prior the NH peak) (Figure 4). A recent study by Hao et al (2015) also pointed to changes in Antarctic ice volume driving prolonged interglacial conditions in the NH during MIS 15-13. More research is required to substantiate this interhemispheric linkage, but it does provide a plausible explanation for the apparent connection between SH records and the warming seen in western Beringia.…”

On the importance of grain size in luminescence dating using quartz

“…MST is the laboratory code used at the Mostistea section from the Romanian Plain Timar-Gabor et al, 2012). CST samples were taken from Costineş ti section near the Black Sea shore (Timar-Gabor and Wintle, 2013;Constantin et al, 2014), samples coded as LCA come from Lunca section in South Western Romania , samples coded as ORL are quartz extracts from Serbian loess , samples coded with XF come from Xifeng section in the Chinese loess plateau (Hao et al, 2012(Hao et al, , 2015 (see details in the supplementary material), while sample coded as RUH comes from Ruhama desert loess section in Israel (Wieder et al, 2008). In addition, samples with an origin other than loess were investigated.…”

High-resolution enviromagnetic records of the last deglaciation from Dali Lake, Inner Mongolia

“…Research in this region on tectonic (Guo et al, 2002), orbital (Deng et al, 2006;Ding et al, 2002;Hao et al, 2015;Heller and Liu, 1984) and millennial scales (Ding et al, 1998;Guo et al, 1996;Porter and An, 1995) has provided a wealth of information on global and regional climate changes. The climate instability during the last deglaciation in semi-arid East Asia was mostly reported in the Loess Plateau (Ding et al, 1998;Guo et al, 1996;Zhou et al, 1999).…”