摘要
In September 1997, a 15-m firn core was recovered from an elevation of 7 000 m a. s.l. from the Dasuopu Glacier in the central Himalayas. The analysis of δ18O values and major ion (Ca2+ , Mg2+ , NH4+ , SO2- and NO3-) concentrations shows that average annual accumulation is 0.75 m (water equivalent) in the Dasuopu firn core. The seasonal variations of δ18O values and major ion concentrations in the core indicate that present summer monsoon and
In September 1997, a 15-m firn core was recovered from an elevation of 7 000 m a. s.I, from the Dasuopu Glacier in the central Himalayas. The analysis of δ18O values and major ion (Ca2+, Mg2 +, NH, 4 + , SO 4 2? - and NO 3 ? ) concentrations shows that average annual accumulation. is 0.75 m (water equivalent) in the Dasuopu firn core. The seasonal variations of δ18O values and major ion concentrations in the core indicate that present summer monsoon and dust signals are recorded with high-resolution in the Dasuopu Glacier. δ18O in precipitation are controlled by amount effect in summer monsoon season, more negative δ18O is representative of summer monsoon signal in snow layers. Higher concentrations of Ca2 +, Mg2 +, SO 4 2? and NO 3 ? are dominated by spring dust storm imput derived from the arid and semi-arid desert regions in central Asia. Also EOF analysis verifies that high spring concentrations of major ions are consistent. Due to the possibly different sources, the secondary variations of NH 4 + and NO 3 ? are negatively relevant with that of Ca2 + and Mg2 +.
