Correlation between climate events in the North Atlantic and China during the last glaciation

Abstract

EPISODES of massive iceberg release (Heinrich events)^1-3 into the North Atlantic Ocean during the last glaciation were associated with recurring episodes of unusually cold North Atlantic surface water (Bond cycles)⁴ and cold air temperatures over Greenland (Dansgaard-Oeschger events)^5,6. Four of the youngest of these cold events have also been reported in climate records from sites outside the North Atlantic region⁷, but until now the entire suite has been identified only in North Atlantic marine sediments, Greenland ice-core records and, tentatively, in French lake sediments⁸. Here we examine grain-size data from Chinese loess and intercalated accretionary palaeosols of last-glacial age for evidence of similar climate signals remote from the North Atlantic region. We see grain-size maxima with ages that match those of the last six Heinrich events, which we interpret as an indication of the changing strength of the East Asian winter monsoon, which largely controls the transport and deposition of central Asian aeolian dust. Thus it seems that these Heinrich events have left their signature in the Chinese loess record. This is consistent with simulations of the glacial climate⁹, which imply that the climates of the North Atlantic and China were linked by the effect of westerly winds.