Characteristics of dust particles and their hydrochemical influence in Mingyong Glacier ice-meltwater, Meili Snow Mountains, China

Abstract This study systematically analyzes the size distribution, concentration characteristics, atmospheric sources, and their coupling relationships with hydrochemical components of dust particles in glacial ice and meltwater from the Mingyong Glacier on the southeastern margin of the Tibetan Plateau. It reveals the transport patterns, source characteristics, and coupling relationships with hydrochemical components of local dust particles. The results indicate: (1) The average size (i.e., particle diameter) (2.01 μm), number concentration (1622.19 × 10 4 mL −1 ), and mass concentration (2699.32 × 10 4 µg kg −1 ) of dust particles in glacial ice are significantly higher than those in meltwater (1.63 μm, 551.75 × 10 4 mL −1 , and 251.57 × 10 4 µg kg −1 , respectively), with the hydraulic sorting effect of meltwater being an important mechanism for this difference. (2) Meltwater dust particle exhibits a unimodal distribution throughout the year (median size 14.15 μm) with relatively homogeneous sources, while glacial ice dust particle shows a multimodal distribution during the accumulation period, indicating more complex sources. (3) Backward trajectory analysis indicates that dust particle during the accumulation period is primarily transported over long distances (Central Asia, Southwest Asia), controlled by stable westerly circulation, while during the ablation period, it is mainly from local Tibetan Plateau and neighboring areas via short-range transport, influenced by the interaction between westerlies and monsoons. (4) Hydrochemical analysis shows that ions in the water primarily originate from carbonate and silicate rock weathering. Correlation and wavelet coherence analyses reveal that the mass concentration of dust particle in glacial ice is significantly positively correlated with TDS (Total Dissolved Solid) and major ions, with coherence periods of 2–4 days or 4–8 days and phase lags at different times. The number concentration of dust particles in meltwater is significantly positively correlated with regional air temperature and precipitation, with temperature consistently leading the dust concentration. This study clarifies that dust particles in the Mingyong Glacier are influenced by both regional and distant sources, and their release process is closely coupled with glacier ablation, hydrological processes, and seasonal shifts in atmospheric circulation. It provides data support for further understanding the glacier-dust-climate interaction mechanisms in the southeastern Tibetan Plateau.