积雪淋溶作用对冰川雪层内主要阴、阳离子记录的影响

The Ion Elution Effect on the Main Ion Profiles of the Glacier Snowpacks

利用乌鲁木齐河源１ 号冰川初始消融季节的连续雪坑离子浓度剖面，初步探讨本区冰川雪层中离子淋溶作用的特征及其对雪冰化学记录的影响。结果表明原始积雪内的大部分化学成分随融水向下渗浸，并富集在雪／ 冰界面处或附加冰内。当冰川消融进一步加剧、导致大部分离子成分随融水进入冰川径流，则会最终形成离子浓度很低的冰川冰，冰芯之定量记录将蜕变为定性结果。另有证据表明各离子间不仅存在淋溶择优性，而且各离子在不同淋溶阶段被淋滤的程度也具有较明显的差异。

The successive main ion profiles of the snowpit samples collected from No.1 Glacier at the head of the Urumqi River during the early ablation period of 1996 were compared to investigate the factors that affect the re location of the ionic species within the glacier snowpacks. It is found that most of the main ions preserved in the snowpacks since the precious melt season had percolated downwards, then were stopped at the snow/ice boundary or in the super imposed ice layer, where layers with significantly high ionic concentrations were observed. When heavy melting happened, most of the ions might be released from the snowpacks with the glacier runoff, consequently the glacier ice with extremely low ion concentrations would form. Thus it is suggested that the ion elution processes might deteriorate the quality of ice core chemical records for paleoenvironment reconstruction. In addition, preferential elution was observed among the main ions, and the leaching degree varied significantly for different ions at different leaching stages.