Advances in Earth Science
• Articles •
Li Xiangying,Li Zhongqin,Chen Zhenghua,Zhao Zhongping,You Xiaoni,Zhu Yuman. Seaspnal Variations and Elution Processes of pH and Electrical Conductivity in Snowpits on Glacier No.1 at the Urumqi River Head, Tianshan[J]. Advances in Earth Science, 2006, 21(5): 487-495.
Analysis of pH and electrical conductivity in surface snow and snowpit samples collected successively in a weekly basis from September 14, 2002 to September 28, 2004 on the east branch of Glacier No.1 at the Urumqi river head, Tianshan is presented. pH and electrical conductivity in surface snow show obvious seasonal variations, which to some extent are associated with the dominant NE and ENE valley wind. The pH in surface snow is more alkaline and electrical conductivity in surface snow reaches maximum in spring because of the Asian dust storm increases and primary aerosols contribution; pH in surface snow is less alkaline and electrical conductivity in surface snow reaches minimum in winter due to the transformation of primary aerosol to secondary aerosol. During the post-depositional processes (October 4, 2003 September 8, 2004), pH and electrical conductivity in snowpits duing different periods show visible seasonal characteristics and elution processes. The date that the peak value P1 of electrical conductivity in snowpit merges into firn ice is about 40 days prior to that of large particles (Diameter>10μm) merging into firn ice. To some extent, the peak values of pH and electrical conductivity in some snowpits occur near dust layers and their peak values also correspond to the dust layers in snowpits, which imply that dust layers probably had an influence on elution processes of soluble ions. Electrical conductivity observations indicate different elution of some of ions in snowpits, the elution of soluble ions is more likely and easier to happen than that of insoluble ions in snowpits. Furthermore, correlation analysis shows that Ca2+ is the key ion determining pH and electrical conductivity in surface snow.