Location and chemical form of aerosol-origin impurities within Antarctic snow packs

利用本研究中开发的氟染料浸渍法，我们对南极积雪中的气溶胶源颗粒进行了微观观察和微拉曼分析。在地表积雪中，很少发现微米级的杂质颗粒；包体中未检测到水溶性盐的拉曼信号。另一方面，在封闭深度附近的铁中，观察到许多以硫酸钠和硫酸钙为主的超微颗粒。这些结果表明，亚微米水溶性气溶胶沉积到地表积雪后，随着积雪深度的增加，气溶胶源颗粒发生了化学物质的再分配和反应，导致气溶胶源颗粒的活跃生长和变化。

Using the fluorinert-immersion method developed in this study, we performed microscopic observations and micro-Raman analysis of aerosol-origin particles within Antarctic snow pack. In surface snow cover, impurity particles of micron-size were rarely found; and Raman signals of water-soluble salts were not detected from these inclusions. On the other hand, in firn near the close-off depth, a number of supermicron particles that mainly consist of the sodium and calcium sulfates were observed. These findings indicate that, after the deposition of submicron water-soluble aerosol to surface snow cover, the redistribution and reaction of chemical species occur in firn, resulting in the active growth and alteration of aerosol-origin particles with increasing snow-depth.