慕士塔格冰芯硝酸盐氮氧同位素记录的过去500年来大气活性氮含量变化研究

项目名称： 慕士塔格冰芯硝酸盐氮氧同位素记录的过去500年来大气活性氮含量变化研究

项目编号： No.41501077

项目类型： 青年科学基金项目

立项/批准年度： 2016

项目学科： 天文学、地球科学

项目作者： 姚平

作者单位： 中国科学院青藏高原研究所

项目金额： 28万元

中文摘要： 冰芯硝酸盐氮氧同位素是准确重建大气活性氮含量和定量化区分活性氮来源的良好指标。本项目拟以慕士塔格山扩扩色勒冰川为研究对象，以硝酸盐氮氧同位素为主要指标，通过对雪坑和现代降水样品的检测，获得现代大气活性氮的沉降特征，明确研究区域雪冰中硝酸盐氮氧稳定同位素的阈值范围、季节变化特征以及可能的活性氮来源，并对各自的贡献比例进行定量化计算。在此基础上，利用已获得的扩扩色勒深冰芯重建过去500年来大气活性氮含量的变化历史，并通过与该地区其他冰芯相关记录的对比分析，揭示过去500年来，尤其是工业革命前后人类活动对该地区活性氮沉降在种类、程度及趋势的差异。本项目将获得的大气活性氮的现代沉降过程和长时间尺度变化记录，不仅有助于了解硝酸盐氮氧同位素在青藏高原雪冰中的指示意义，拓宽青藏高原雪冰化学的研究范畴；也将通过对比工业革命前后人类活动对该地区氮沉降影响程度的差异为评估人类活动对青藏高原的影响提供科学依据。

中文关键词： 冰芯；硝酸盐；氮氧同位素；气候变化；人类活动

英文摘要： Nitrogen and oxygen stable isotope of nitrite is an excellent tracer to reconstruct the content of reactive nitrogen precisely and has an enormous potential for quantifying contributions from different nitrogen sources. Focusing the Kuokuosele Glacier on the Mt. Muztagh Ata, snow pit and fresh precipitation samples will be collected at the beginning of this project. Nitrogen and oxygen stable isotope of nitrite and the nitrite concentration will be analyzed using the denitrifier method and ion chromatography technology. The modern deposition mechanism will be diagnosed through its value, seasonal characters, specific sources and theirs contributions. And then the atmospheric reactive nitrogen content during the past 500 years will be reconstructed from the deep ice core drilled in 2012 from the same glacier. On the base of comparing with previous ice-core records in this area, the historical variation, specific natural and anthropogenic sources and their inputting transformation will be assessed, especially the influence of human activities after the industrial revolution era. The modern deposition process and the historical record of atmospheric reactive nitrogen will not only broaden our knowledge of glaciochemical science, but also offers dependable evidences about influence of human activities.

英文关键词： Ice core;nitrate;nitrogen and oxygen isotope;climate change;human acitivity