Biogenic Sources of Oxygenated Hydrocarbons in the Troposphere

小行星94180730 利用早期赠款进行的研究发现了甲醇和其他挥发性有机化合物（VOC）从植被到大气的主要通量。现在建议使用灵敏和特异的酶/荧光方法来测量主要森林树种和作物中甲醇和其他含一个碳的含氧碳氢化合物的排放，并确定叶片细菌作为这些化合物的汇的作用。所获得的数据将被用来开发排放算法，将在现场实验中验证，并在未来可能会被用作美国的生物源C1-oxHCs排放清单的基础。植物C1-oxHC通量到大气中可能是非常大的，无论是区域和全球范围内，与远距离传输的甲醇和各种影响大气化学。目前，这些通量估计存在很大的不确定性。该项目将有助于更全面地了解甲醇，甲醛和甲酸在生物圈和大气之间的地球化学循环，并帮助建立这些C1化合物的自然源和汇的知识。 本研究的主要目标是：（1）完善植物C1-oxHC排放的酶法和荧光法分析方法，（2）确定植物C1-oxHC排放的驱动因子，并在实验室和温室实验中收集大量的C1-oxHC排放数据，（3）开发生物源C1-oxHC的排放算法，（4）建立植物C1-oxHC的排放模型。（4）确定叶片细菌作为大气C1-oxHC源和/或汇的作用;（5）通过适当的C1-oxHC通量实地测量，验证实验室排放算法。

94180730 Fall Research conducted with earlier grants has resulted in the discovery of major fluxes of methanol and other volatile organic compounds (VOCs) from vegetation to the atmosphere. It is now proposed to use sensitive and specific enzyme/fluorescence methods to measure the emission of methanol and other oxygenated hydrocarbons containing one carbon from major forest tree species and crops, and establish the role of leaf bacteria as sinks for these compounds. The data obtained will be used to develop emission algorithms that will be validated in field experiments and in the future might be used as the basis of a US emissions inventory of biogenic C1-oxHCs. Plant C1-oxHC fluxes to the atmosphere may be very large, both regionally and globally, with long range transport of methanol and a variety of impacts on atmospheric chemistry. Currently there are large uncertainties in these flux estimates. This project will contribute to a more complete picture of the biogeochemical cycling of methanol, formaldehyde, and formic acid between the biosphere and atmosphere, and help establish knowledge of natural sources and sinks of these C1 compounds. The specific goals of the proposed work are: (1) to perfect enzymatic and fluorescence methods for analyzing methanol, formaldehyde, and formic acid emissions from vegetation; (2) to define the "drivers" of plant C1-oxHC emissions and collect a large data set of oxHC fluxes in laboratory and greenhouse experiments; (3) develop emission algorithms for biogenic C1-oxHCs; (4) to establish the role of leaf bacteria as sources and/or sinks of atmospheric C1-oxHCs; (5) and to validate laboratory emissions algorithms by appropriate field measurements of C1-oxHC fluxes.