乌鲁木齐河源1号冰川不溶微粒的季节变化特征

冰芯中的不溶微粒是反映大气粉尘的良好指标，亦是冰芯定年的重要方法。为了探究不溶微粒在雪层中的季节变化特征，对采自乌鲁木齐河源1号冰川4 130 m处的雪冰样品进行不溶微粒分析。表层雪中粗微粒浓度在一年中有2个峰值，分别出现在12~3月、6~9月；总微粒只有一个峰值区，出现在4~8月。对比同期气象资料发现，其受降水、大气环流以及局地风影响显著。结合雪层物理剖面和微粒在雪层中的浓度发现：污化层是粗颗粒（直径大于10 μm）聚集的区域。对该粒径范围的微粒浓度峰值进行跟踪，发现不溶微粒在雪层中的浓度和位置变化与融水、物理成冰过程密切相关。

Seasonal Evolution of Insoluble Microparticles Stratigraphy in Glacier No.1 Percolation Zone, Eastern Tianshan, China

The atmospheric dust is one of the most important factors in the global climate changes. Its effects include the scatter and reflect of solar insolation, the supply to the Iron fertilizer to ocean, and its restrain to rain. The microparticles record in ice cores is an excellent proxy for atmospheric dust. Therefore, the processes involved in the evolution of vertical profiles of microparticle concentrations as well as their seasonal variation in surface snow were studied by weekly sampling a snow pit from September 2003 to September 2004 on Glacier No. 1 in the eastern Tianshan. The development of the microparticle stratigraphy in the snow pit is closely related to the physical development of the snow-tim pack. The sampling site is located at 4130 m asl in the percolation zone of the glacier, and in addition to the effects of sublimation and wind erosion, melting plays a crucial role in both the physical and chemical evolution processes. During the winter season, aerosol concentrations in the surface layers are altered slightly by sublimation and wind erosion, and the concentrations are further modified as the wet season begins in late April. In contrast, aerosol stratigraphy in the deeper layers remains relatively unchanged through the winter. In early summer, as melting occurs in the upper part of the snow-tim pack, meltwater carries microparticles to different depths in the underlying snow-tim layers. At the end of the ablation season, all of the surface elements might be leached out from the upper layers.