根据2004年11月至2005年10月在天山乌鲁木齐河源1号冰川积累区采集的雪坑样品研究发现,雪层中NO3-平均浓度存在季节性变化特征,湿季(4~10月)的NO3-浓度明显低于干季(11月至次年3月)。特别是在春季,在雪层上部出现的浓度峰,经过夏季淋溶改造,稀释并合并为稳定的浓度峰;雪层中各浓度峰普遍处于向下迁移的过程中。在后沉积过程中,距底部附加冰70~80 cm附近的雪层处存在一个过渡层,上部变化强烈,下部相对稳定;强淋溶期可以使NO3-溶质含量减小20%~60%。
Based on the snowpit samples collected at the accumulation zone of Glacier No.1 at the headwaters of Urumqi River in the Tianshan Mountains from November 2004 to October 2005,nitrate(NO-3) concentration in snowpacks is analyzed.Seasonality is displayed for the mean NO-3 concentrations in snowpacks,and the concentrations are higher in the dry season(from November to March) and lower in the wet season(from April to October).At the upper section of snowpacks,the spring-formed NO-3 concentration peaks are diluted significantly in the summer,according to the elution effect;for the whole snowpacks,the NO-3 concentration peaks relocate downward.In the vertical profile of snowpack,a transition layer appears at a distance of 70~80 cm to superimposed ice layer;the elution effect above the transition layer is much stronger than that below,and the concentration above the layer is higher than that below.With 20%~60% loss of content during the strong elution period in the post-depositional process,the environmental information is recorded in the ice.