TELE-CONNECTION BETWEEN EAST CHINA SEA AND GREENLAND

A 33.65 m long IMAGES core with very high sedimentation rate (ca. 80cm/ka) from the northern part of the East China Sea was analyzed at 10 cm (about 125 years) intervals using oxygen-carbon isotope of Globigerinoides ruber (sense strict) and sea surface temperature (SST) estimates from alkenones. The general pattern of the oxygen isotope curve is similar to the standard oxygen isotope curve in open ocean and shows many light oxygen isotope peaks similar to Dansgaard-Oeschger (D-O) cycles observed in Greenland ice cores since the last 43 ka. The alkenone SST curve of the core resembles to the oxygen isotope curve. The SST at the core top is 24 degrees centigrade, which is close to the present mean SST in June at the core site. Whereas the SST at the LGM is about 5 degrees centigrade lower than present-day. The alkenone SST curve does not show high values at the light oxygen isotope peaks of the D-O cycles. This suggests that these light oxygen isotope peaks were formed at the warm (D-O) events when fresh water was supplied to the core site. The sea surface salinity reconstruction using the oxygen isotope and alkenone SST values suggests that the low salinity (31-32 psu) events are observed at the LGM, due to the progressive movement of the river mouths of the Yellow and Changjiang Rivers to the core site in response to the sea level drop. Similar salinity drops are also observed at the warm events of D-O cycles, due to the increased precipitation in East China. Tele-connection between East Asia and Greenland must be caused by the meander of the westerly during the cold and warm D-O cycles.