摘要
降雪通过冷型或暖型成冰作用转化为冰川冰, 中国冰川以暖型成冰作用为主.利用在雪层中插置竹板, 通过竹板进行层位跟踪的方法, 历时24个月连续观测, 研究了1号冰川积累区(海拔4 130 m)降雪演化为粒雪冰的时间问题.结果表明: 夏季, 新雪转化为细粒雪约需要7 d, 细粒雪转化为粗粒雪约20 d到3个月; 同样的转化在冬季分别需要约2.5个月和2～4.5个月.粗粒雪转化成粒雪冰的时间大约40个月.由此得到该处新雪演化为粒雪冰历时约41～47个月.8～9月为雪粒演化的主要成冰期.不同层位雪层的密实成冰速率因粒雪性质和密度的不同而有很大差别, 融水是影响成冰时间及成冰量的重要因素.
Fresh snow transfers to glacier ice through a cold or a warm ice formation process. In China, the transformation of most glaciers takes place following a warm ice formation process. However, the time scale of the transformation from snow to ice is poorly documented in literatures. The main reason for it is of lack of longterm field observation data. In this paper, an explicit transformation period from snow to ice on the accumulation zone （4 130 m） of the Glacier No. 1 is given out based on a 24- month continuous observation of snow pits profiles by employing snow layer-tracing method. The study demonstrates that, in summer, the time for snow developing to fine firn is about 7 days, and the time for fine firn turning to coarse firn is about 20 days～3 months. The same transformation processes take about 2. 5 months and 2～4.5 months in winters. Thus, the total snow to ice transformation age at this site is about 41～47 months. In this paper, the seasonal variability of snow layer＇s movement, the relationship between movement velocity changing with snow depth and density, and the magnitude of ice formation in summer are also discussed. It is concluded that the late summer （August--September） is a main period for ice formation, and melting water greatly affects the snow to ice transformation process.
出处
《冰川冻土》
CSCD
北大核心
2005年第6期853-860,共8页
Journal of Glaciology and Geocryology
基金
中国科学院寒区旱区环境与工程研究所引进国外杰出人才基金项目(CACX2003101)
国家自然科学基金项目(403710284030100990102005)
国家自然科学基金创新群体项目资助
关键词
1号冰川
成冰年限
层位跟踪
Tianshan Mountains
Glacier No. 1
ice formation age
transformation of snow to ice
