The Isotopic Composition of Atmospheric Formaldehyde, FormicAcid and Acetic Acid

该项目旨在通过收集样本的同位素组成来评估美国偏远大陆地区大气甲醛、甲酸和乙酸的各种来源的相对重要性。在选定地点：(a)将确定大气甲醛的碳同位素组成，并与这些地点的主要来源- -甲烷和天然非甲烷碳氢化合物的组成进行比较。因此，应评估这些来源对通过甲醛产生一氧化碳的碳通量的相对贡献。(b)将测定甲酸和非甲酸轻单羧酸的碳同位素组成，并将它们与甲醛和其他主要的人为和自然有机排放物进行比较，以推断可能的来源贡献。具体而言，该项目将改进现有的收集和整理技术，确定三种大气物种的13C和14C含量，估计当地工厂排放的13C含量，并确定相对的人为影响。

This project seeks to evaluate the relative importance of the various sources of atmospheric formaldehyde, formic acid and acetic acid at remote continental locations within the US from the isotopic composition of collected samples. At chosen locations: (a) The carbon isotopic composition of atmospheric formaldehyde will be determined and compared to the compositions of the principal sources at those sites - methane and natural non-methane hydrocarbons. The relative contributions of these sources to the carbon flux through formaldehyde to carbon monoxide should thus be evaluated. (b) The carbon isotopic compositions of formic acid and non-formic light mono-carboxylic acids will be determined and compared to each other, to formaldehyde and to other major organic emissions, both anthropogenic and natural, to deduce likely source contributions. Specifically the project will refine existing collection and work-up techniques, determine the 13C and 14C content of the three atmospheric species, estimate the 13C content of local plant emissions, and determine the relative anthropogenic influence.