Abstract:
The oxygen isotope value (
δ18O) of foraminiferal shell depends upon the
δ18O and temperature of sea water. The seawater temperature, therefore, can be extracted from foraminiferal
δ18O if the
δ18O composition of sea water is known. In this paper, the planktonic foraminifera
Globigerinoides ruber picked out from the nine sediment cores in the northern South China Sea were analyzed for
δ18O. Using the published summer and winter sea water
δ18O values at each site, we calculated the sea water temperature (
Truber), and then comparison was made for
Truber and the 0~30m water temperature download from the World Ocean Atlas (WOA) database. Our data shows that there is a large difference between
TWOA and
Truber when summer water
δ18O was used in calculation, however, the difference was in a reasonable range when winter water
δ18O was used. It suggests that
δ18O
ruber reflects better the temperature and
δ18O composition of winter seawater, and further implies that the productivity and deposition flux of
G.ruber may reach the maximum when the East Asian Winter Monsoon prevails.