In June 2006, samples were collected from a 90 cm snow-pit at an elevation of 5 040 m a.s.l, in the northern branch firn basin of the Glacier No. 12, Laohugou Valley, in the western part of Qilian Mountain, China. Oxygen isotopes （6180） and major soluble ions were measured. Results showed that Ca2＋ is the dominant cation, and SO42 is the dominant anion. All major ions have close positive correlations with eachother except NO3 and NH4＋. 6180 show positive correlation with air temperature. The method of correlation analysis, sea-salt ion tracer and trend analysis were used to determine the source of the chemical components. The correlation analysis and HYSPLIT backward trajectory analysis suggest that atmospheric soluble dust species dominate the chemical signature.
Xiaoqing CuiJiawen RenXiang QinWeijun SunGuangming YuZebin WangWeigang Liu
Retrieval of oxalate from snow and ice provides information on past environmental changes. In recent years, records of organic acids in middle-and low-latitude glaciers have attracted the attention of researchers globally. In this study, we analyzed oxalates in an ice core from Laohugou Glacier No. 12 on the Qilian Mountains at an elevation of 5,040 m a.s.l. in2006. Average oxalate concentration was 18.5±2.4 ng/g over the prior 46 years. Oxalate values showed a significantly increasing trend since 1985. From 1985 to 1995, oxalate concentrations had large fluctuations, peaking in about 1987 and exhibiting a slightly decreasing trend since 1995. The result shows that the abrupt increase of oxalate concentration in the ice core since the mid-1980 s reflects atmospheric environmental pollution by human and industrial activities.
