Title

Monsoon and dust signals recorded in Dasuopu glacier, Tibetan Plateau

Abstract

During summer 1997, a 15 m firn core was recovered from Dasuopu glacier (28°23′ N, 85°44′ E; 7000 m a.s.l.) on the northwest margin of Xixabangma Feng in the central Himalaya. Oxygen isotope values and concentrations of Ca2+, Mg2+, NH4+, SO42− and NO3 were measured over the 10 years of snow accumulation captured in the firn core. The seasonal variations of 18O values and major-ion concentrations in the Dasuopu core indicate that summer monsoon and dust signals are clearly recorded in Dasuopu glacier. Annual variations in 18O values are controlled by the amount effect, with more negative (i.e. lighter) 18O values representing summer monsoon precipitation characteristic of tropical regions. Higher concentrations of Ca2+, Mg2+ and SO42− reflect the influx of mineral aerosols from the vast arid and semi-arid desert regions to the north and west during the spring dust-storm period. High spring concentrations of NH4+ and NO3 appear to reflect changes in regional biogenic-source strength.

Publication Date

3-2000

Journal Title

Journal of Glaciology

Publisher

International Glaciological Society

Digital Object Identifier (DOI)

10.3189/172756500781832864

Document Type

Article