南极洲乔治王岛柯林斯冰帽表层积雪可溶杂质浓度特征

CONCENTRATION CHARACTERISTICS OF SOLUBLE IMPURITIES IN THE SURFACE SNOW OF COLLINS ICE CAP, KING GEORGE ISLAND,ANTARCTICA

柯林斯冰帽主冰穹冰芯上部10m的分析结果,揭示了积雪可溶杂质与大气气溶胶化学构成之间的直接联系。由于发育于典型的极地海洋环境,海盐气溶胶是柯林斯冰帽周围大气气溶胶的主要成分。积雪中Na^+、K^+、Mg^(2+)、Ca^(2+)、SO_4^(2-)、Cl^-、Br^-浓度-深度剖面的同步变化以及EF值的相近(≈1),说明了这些杂质降落以前具有共同源地,且经历了相近的沉积方式。NH_4^+除表层污染外,下部变化均匀,可代表当地铵基的本底变化。对NO_3^-的剖面变化目前尚不能得到完满的解释。

Measurements carried out for the upper 10m firn/ice core obtained at the main dome of Collins Ice Cap,King George Island,Antarctica revealed the direct association of soluble impurities of snow mass with the composition of atmosphere aerosols around Collins Ice Cap. The simultaneous variation shown by the concentration profiles of Na^+/K^+/Mg^(2+)/ Ca^(2+)/SO_4^(2-)/Cl^-/Br^- and Very approximate EF value (≈1) of them suggested a common marine source from which they originated before incorporated into snow, and experienced a similiar deposition process. Besides the possible surface contamination, NH_4^+ varied uniformly along the deeper part of the core in concentration, which could he considerect as background value of ammonium. A satisfactory explanation for NO_3^- concentration profile could not be obtained at present.