稳定同位素模型解析大气氨来源的参数敏感性  

Source Apportionment of Atmospheric Ammonia:Sensitivity Test Based on Stable Isotope Analysis in R Language

作　　者：顾梦娜 潘月鹏[1,2] 何月欣 田世丽 王彦君[1] 吕雪梅 倪雪 孙杰 吴电明[3] 方运霆 GU Meng-na;PAN Yue-peng;HE Yue-xin;TIAN Shi-li;WANG Yan-jun;LüXue-mei;NI Xue;SUN Jie;WU Dian-ming;FANG Yun-ting(State Key Laboratory of Atmospheric Boundary Layer Physics and Atmospheric Chemistry,Institute of Atmospheric Physics,Chinese Academy of Sciences,Beijing 100029,China;University of Chinese Academy of Sciences,Beijing 100049,China;Key Laboratory of Geographic Information Sciences,Ministry of Education,School of Geographical Sciences,East China Normal University,Shanghai 200241,China;Key Laboratory of Forest Ecology and Management,Institute of Applied Ecology,Chinese Academy of Sciences,Shenyang 110016,China)

机构地区：[1]中国科学院大气物理研究所,大气边界层物理和大气化学国家重点实验室,北京100029 [2]中国科学院大学,北京100049 [3]华东师范大学地理科学学院,教育部地理信息科学重点实验室,上海200241 [4]中国科学院沈阳应用生态研究所,森林生态与管理重点实验室,沈阳110016

出　　处：《环境科学》2020年第7期3095-3101,共7页Environmental Science

基　　金：国家重点研发计划项目(2016YFC0201802,2017YFC0210100,2017YFC0212703);国家自然科学基金项目(41807311)。

摘　　要：氨(NH3)是大气霾污染和过量氮沉降的关键前体物,准确厘清其来源是制定NH3减排策略的科学基础.稳定同位素模型(SIAR)在NH3溯源研究中展现出巨大潜力,其解析结果的可靠性与NH3排放源的氮同位素指纹谱(δ15N-NH3)密切相关.本研究基于2013年1月北京霾污染期间的同位素观测资料,使用SIAR评估了3个重要源谱参数(源的数量、源的δ15N-NH3特征值及其标准差)对NH3源解析的影响.结果表明,农业源的贡献率对源谱δ15N-NH3特征值的变化最敏感,其次为化石燃烧源,氨逃逸源的敏感性最低.农业源δ15N-NH3标准差的改变仅造成农业源贡献率变化约4%,但其特征值的改变却造成农业源贡献率20%的变化.相比之下,将农业源拆分为化肥挥发和畜牧养殖源后,解析结果并未显著增加农业源的总贡献,即"非农业源"仍然是2013年初北京霾污染期间NH3的重要来源.考虑到农业源的贡献率对SIAR模型参数改变的响应最为敏感,且不同类型的农业源δ15N-NH3差异较大,未来需要针对农业源δ15N-NH3的时空变化规律及影响因素开展深入研究,以此来降低同位素源解析模型的不确定性.Ammonia(NH3)is an important precursor of fine particles and nitrogen deposition.It is critical to identify and quantify the sources of NH3 before the implementation of a mitigation strategy.Stable isotope analysis in R(SIAR)has potential with regard to the source apportionment of NH3,but its reliability is closely related to the signatures(δ15N-NH3)of emission sources.Based on SIAR,we found that the agricultural contribution varied significantly with meanδ15N-NH3 values of endmember input.In contrast,both the contributions of fossil fuel and NH3 slip showed low sensitivity against the change of endmember input.Moreover,the agricultural contribution changed by about 20%due to the variations in agricultural endmember mean values.Such a change is five times that due to the variations in endmember standard deviation values.Notably,regardless of the number of input sources tested,"non-agricultural source"was the dominant source of NH3 during hazy days in January 2013 in Beijing.Since various agricultural sources showed large variations inδ15N-NH3,future studies should focus on the endmember signatures of agricultural sources to further reduce the uncertainty in SIAR-based NH3 source apportionment.

关 键 词：氨气 同位素 源谱 稳定同位素模型(SIAR) 源解析 

分 类 号：X511[环境科学与工程—环境工程]