Spatial variation of isotopic compositions of snowpack nitrate related to post-depositional processes in eastern Dronning Maud Land, East Antarctica
Spatial variation of isotopic compositions of snowpack nitrate related to post-depositional processes in eastern Dronning Maud Land, East Antarctica
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DOI：
10.2343/geochemj.2.0519
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发表时间：
2018-03
影响因子：
0.8
通讯作者：
K. Noro;S. Hattori;R. Uemura;K. Fukui;M. Hirabayashi;K. Kawamura;H. Motoyama;N. Takenaka;N. Yoshida
中科院分区：
文献类型：
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作者：
K. Noro;S. Hattori;R. Uemura;K. Fukui;M. Hirabayashi;K. Kawamura;H. Motoyama;N. Takenaka;N. Yoshida
例如，2009年; Jacobi和Hilker，2007年; Röthlisberger等人，2000年）。沉积后损失过程，即，硝酸（HNO 3）的挥发和硝酸盐的光解，长期以来一直存在争议（Blunier等人，2005; Röthlisberger等人，2000）。然而，利用雪中硝酸盐的稳定同位素组成，最近在野外、实验室和模型实验中表明，硝酸盐的损失是由紫外线光解主导的，特别是在寒冷条件下（Berhanu等人，2014; Erbland等人，2013; Frey等人，2009年）。HNO 3挥发和相关的同位素分馏在高于-20 ° C的较暖温度下可能变得重要（Erbland等人，2013年）。迄今为止，注意力集中在南极洲东部地表雪的光解NO3 -损失的空间变异性。这种可变性已被沿着Dumont d 'Urville站（在Adelie Land）和东方之间的导线研究，穿过Dome C（Erbland等人，2013），以及沿着一条从东南极海岸到Dome Argus（Shi等，2015年）的报告。根据这些研究，很明显，在低积累地点，硝酸盐光解导致表层雪中硝酸盐浓度降低，在10 cm深度以下从数百到数十mg L-1，以及东南极洲德龙宁毛德地东部与沉积后过程有关的积雪硝酸盐同位素组成的空间变化
et al., 2009; Jacobi and Hilker, 2007; Röthlisberger et al., 2000). The relative importance of post-depositional loss processes, i.e., volatilization of nitric acid (HNO3) and photolysis of nitrate, has long been debated (Blunier et al., 2005; Röthlisberger et al., 2000). However, using the stable isotopic composition of nitrate in snow, it has recently been shown in field, laboratory and model experiments that nitrate loss is driven by UV photolysis dominates, especially under cold conditions (Berhanu et al., 2014; Erbland et al., 2013; Frey et al., 2009). HNO3 volatilization and associated isotopic fractionation may become important at warmer temperatures, greater than –20∞C (Erbland et al., 2013). To date, attention has focused on the spatial variability of photolytic NO3 – loss from surface snow in East Antarctica. This variability has been investigated along a traverse between the Dumont d’Urville station (in Adelie Land) and Vostok, passing through Dome C (Erbland et al., 2013), as well as along one from the East Antarctic coast to Dome Argus (Shi et al., 2015). Based on these studies, it is apparent that, at low accumulation sites, nitrate photolysis results in decreased nitrate concentration in the surface snow, from hundreds to tens of mg L–1 below a depth of 10 cm, and Spatial variation of isotopic compositions of snowpack nitrate related to post-depositional processes in eastern Dronning Maud Land, East Antarctica