title: Physicochemical impacts of dust particles on alpine glacier meltwater at the Laohugou Glacier basin in western Qilian Mountains, China.
abstract: This work discusses the temporal variation of various physicochemical species in the meltwater runoff of Laohugou Glacier No. 12 (4260 ma.s.l.) in central Asia, and their correlation with dust particles, based on a two-year field observation in summer 2012 and 2013, mainly focusing on dust concentration and size distribution, meltwater chemistry, particles SEM-EDX analysis in the meltwater, and MODIS atmospheric optical depth fields around the Qilian Mountains in central Asia. We find that, the volume-size distribution of dust particles in the meltwater is mainly composed of three parts, which includes fine aerosol particles (with diameter of 0~3.0 μm, mainly PM 2.5), atmospheric dust (with diameter of 3.0~20 μm), and local dust particles (20~100 μm), respectively. Comparison of dust particles in the snowpack and meltwater runoff indicates that, large part of dust particles in the meltwater may have originated from atmospheric dust deposition to the snow and ice on the glacier, and transported into the meltwater runoff. Moreover, temporal variation of dust and major ions (especially crustal species) is very similar with each other, showing great influence of dust particles to the chemical constituents of the glacier meltwater. SPM and TDS implied significant influences of dust to the physical characteristics of the glacier meltwater. Results showed that, accelerated glacier melting may affect physicochemical characteristics of the meltwater at an alpine basin under global warming. MODIS atmospheric optical depth (AOD) fields derived using the Deep Blue algorithm, showed great influence of regional dust transportation over western Qilian Mountains in springtime. SEM-EDX analysis shows that dust particles in the glacier meltwater contain Si-, Al-, Ca-, K-, and Fe-rich materials, such as quartz, albite, aluminate, and fly ash, similar to that deposited in snowpack. These results showed great and even currently underestimated influences of atmospheric dust deposition to glacier meltwater physicochemistry at an alpine basin in central Asia.
authors.affiliation: The State Key Laboratory of Cryospheric Sciences, Chinese Academy of Sciences, Lanzhou 730000, China; Qilian Mountain Glacier and Ecological Environment Research Station, Lanzhou 730000, China. Electronic address: dongzhiwen@lzb.ac.cn.
authors.forename: Zhiwen
authors.initials: Z
authors.lastname: Dong
authors.affiliation: The State Key Laboratory of Cryospheric Sciences, Chinese Academy of Sciences, Lanzhou 730000, China; Qilian Mountain Glacier and Ecological Environment Research Station, Lanzhou 730000, China.
authors.forename: Dahe
authors.initials: D
authors.lastname: Qin
authors.affiliation: The State Key Laboratory of Cryospheric Sciences, Chinese Academy of Sciences, Lanzhou 730000, China; Qilian Mountain Glacier and Ecological Environment Research Station, Lanzhou 730000, China.
authors.forename: Jizu
authors.initials: J
authors.lastname: Chen
authors.affiliation: The State Key Laboratory of Cryospheric Sciences, Chinese Academy of Sciences, Lanzhou 730000, China; Qilian Mountain Glacier and Ecological Environment Research Station, Lanzhou 730000, China.
authors.forename: Xiang
authors.initials: X
authors.lastname: Qin
authors.affiliation: The State Key Laboratory of Cryospheric Sciences, Chinese Academy of Sciences, Lanzhou 730000, China; Qilian Mountain Glacier and Ecological Environment Research Station, Lanzhou 730000, China.
authors.forename: Jiawen
authors.initials: J
authors.lastname: Ren
authors.affiliation: The State Key Laboratory of Cryospheric Sciences, Chinese Academy of Sciences, Lanzhou 730000, China; Qilian Mountain Glacier and Ecological Environment Research Station, Lanzhou 730000, China.
authors.forename: Xiaoqing
authors.initials: X
authors.lastname: Cui
authors.affiliation: The State Key Laboratory of Cryospheric Sciences, Chinese Academy of Sciences, Lanzhou 730000, China; Qilian Mountain Glacier and Ecological Environment Research Station, Lanzhou 730000, China.
authors.forename: Zhiheng
authors.initials: Z
authors.lastname: Du
authors.affiliation: The State Key Laboratory of Cryospheric Sciences, Chinese Academy of Sciences, Lanzhou 730000, China; Qilian Mountain Glacier and Ecological Environment Research Station, Lanzhou 730000, China.
authors.forename: Shichang
authors.initials: S
authors.lastname: Kang
keywords: Anthropogenic activities; Dust particles; Glacier meltwater; Physicochemical constituents; SEM–EDX