摘要

Numerous studies have focused on modern hydroclimate and the modulated mechanisms in the Tianshan Mountains (TMs), arid central Asia. However, the detailed information of hydroclimatic processes beyond the instrumental period is still scarce. This paper reconstructed a hydrology history from core sediments of the Dalongchi Lake in the Tianshan Mountains. The comparability between end-members (EMs) of grain size and ICP-AES based geochemical elements in the lake sediments highlighted their availability for hydrological reconstructions. Hydrodynamic forces (EM1, EM4, Ti/Al and Li/Al), chemical weathering intensity [(Mg+Ca+K)/Al], salinity proxy (Mg/Ca) and redox-sensitive proxy (Fe/Mn) highly correlated with the first principal component (P<0.01), whereas paleoproductivity proxies (TN, TOC, Ba/Al, Zn/Al and Cu/Al) and C/N showed high loadings on the second principal component (P<0.05). The inferred hydrology progress was nonlinearly responded to temperature, precipitation and climate-dictated glaciers. Specifically, the water level didn't always covary with the humidity because of glaciers. The maximum water level was the comprehensive result of glaciers melting and high humidity around 1830 CE. Thereafter, water level continually decreased with declining moisture at high temperature, implying a limited buffering capacity of glaciers in the Dalongchi Lake basin. EM3-indicated eolian activity intensity was caused by the behaviors of Siberian High because the latter intensified surface wind and the dust transportation. The hydrothermal patterns were characterized by warm/dry and cold/wet alternations in a long run although warm/wet pattern was identified from a short-term view.

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