根据天山乌鲁木齐河源1号冰川积累区海拔4130m处28个月,每周1次的连续雪层剖面观测,分析研究了雪层厚度、雪层中的污化层、冰片和各种粒雪随时间的演变过程.结果表明:雪层中各种要素的演变受水热条件的影响而呈现明显的季节特征.根据温度、融水渗浸程度及雪层剖面的变化程度,我们将其分成冬季稳定期、夏季剧变期和春秋季波动期分别进行了分析.此外,还对雪层年限与年成冰量等进行了专门讨论.
Physical process of snow to ice transformation is one of important research objects in Glaciology. However, most previous studies on the Glacier No. 1 focused mainly on properties of snow profiles, rather than the process, because of lack of long-term field observation. The currently launched PGPI (the Program for Glacier Process Investigation) provides a unique opportunity to observe this evolution process and to trace every change in snow-firn pack at PGPI observation and experimental site on the Glacier No. 1, which in turn made a great contribute to PGPI. During PGPI field campaigns from 2002 through to 2004, about 110 snow/firn stratigraphy profiles (in weekly interval) were obtained at PGPI site (4 130 m a. s. 1. , in the percolation zone), on which various physical measurements and observations have been made simultaneously, as a result, the evolution process can be analyzed in detail. Particular effort was contributed to those visible layers on snow-firn stratigraphy, such as different sized firn, dust layers, ice slices, etc. , by tracing their evolution processes. The results have reveled enormous details of these processes over the twoyear period. It is found that percolation of meltwater has a definitive impact on the transformation process. Ice formation process in a year can be divided into four periods depending on features of the process: winter steady period, spring fluctuation periods, summer intense period and autumn fluctuation period. Different periods have been discussed respectively in this paper.