摘要
根据天山乌鲁木齐河源地区的一个完整年周期的大气降水样品、１ 号冰川连续雪坑样品及浅冰芯样品的ｐ Ｈ 和电导率资料， 初步探讨冰芯ｐ Ｈ 和电导率记录的形成过程和影响因素结果表明， 降水沉积后的粒雪化过程和成冰作用过程中样品的ｐ Ｈ 和电导率有较大的变化， 但两者之间仍基本保持正相关关系这说明在消融率较大和融水渗浸作用较强的内陆地区， 仍可以根据冰芯的ｐ Ｈ
Analyses of pH and conductivity in precipitation samples collected from June 1995 to June 1996, in snow pit samples collected during the winter of 1995～1996 and during the summer of 1996, and in shallow ice core samples retrieved in May 1996 from the headwaters of the Urümqi River are presented in this paper The pH values of the precipitation samples were in the range of 5 7～7 9, most of which were close to neutrality The conductivity values of the precipitation samples were in the range of 3 0～292 μS/cm, among which over half of the samples were below 30 μS/cm The low pH values appeared mostly in summer and autumn, while the seasonal variation of the conductivity was not apparent The relationship between pH and conductivity was more complicated at the headwaters of the Urümqi River than that in the other remote places: a negative relationship existed between pH and conductivity on the condition of 5 7<pH<6 3, which was similar to that in polar snow and ice Nevertheless, a positive relationship existed between them on the condition of 6 3<pH<7 9 Though much difference in the pH and conductivity values of the winter snow pits existed at 4 030 m and at 3 900 m a s l owing to the snow re distribution caused by snow drifting, a significant positive relationship still preserved between the pH and conductivity values, which demonstrated that the pH and conductivity values of the winter snowpacks was controlled mainly by the alkaline dust The dissolution of the alkaline dust in meltwater of the summer snowpacks might increase the pH and conductivity values of the summer snow pit samples However, a significant positive relationship still existed between the pH and conductivity values of the summer snow pits Such relationship was also preserved in the ice core pH and conductivity records This fact implies that the post depositional processes do not shift the relationship between the pH and conductivity values, which validates the application of the ice core pH and conductivity records from the zones with seriously melting for paleoclimate reconstruction
出处
《冰川冻土》
CSCD
北大核心
1999年第3期225-232,共8页
Journal of Glaciology and Geocryology
基金
国家自然科学基金
中国科学院 "九五"重大项目
攀登计划项目
中国科学院天山冰川观测试验站基金
关键词
乌鲁木齐河源
PH
电导率
现代环境过程
冰川
the head water of Urümqi River
precipitation
snow and ice
pH and conductivity
the present environmental processes
