Ground-level ozone influenced by circadian control of isoprene emissions
Ground-level ozone influenced by circadian control of isoprene emissions
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DOI：
10.1038/ngeo1271
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发表时间：
2011-10
影响因子：
18.3
通讯作者：
C. Hewitt;K. Ashworth;A. Boynard;A. Guenther;B. Langford;A. Mackenzie;P. Misztal;E. Nemitz;S. Owen;M. Possell;T. Pugh;Annette C Ryan;O. Wild
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作者：
C. Hewitt;K. Ashworth;A. Boynard;A. Guenther;B. Langford;A. Mackenzie;P. Misztal;E. Nemitz;S. Owen;M. Possell;T. Pugh;Annette C Ryan;O. Wild
挥发性有机化合物异戊二烯由许多植物物种产生，并提供针对生物和非生物胁迫的保护。在全球范围内，植物的异戊二烯排放量估计远远超过挥发性有机化合物的人为排放量。一旦进入大气中，异戊二烯就会迅速与羟基自由基反应形成过氧自由基，过氧自由基可以与氮氧化物反应形成地面臭氧。在这里，我们使用马来西亚两个热带生态系统（雨林和油棕榈种植园）的树冠尺度测量异戊二烯通量以及三个大气化学模型来探索异戊二烯通量对地面臭氧的影响。我们表明，这些生态系统中的异戊二烯排放在冠层范围内受到昼夜节律控制，特别是在油棕种植园中。因此，这些生态系统排放的异戊二烯比现有排放模型预测的要少。利用当地、区域和全球尺度的大气化学和运输模型，我们表明，考虑到异戊二烯排放的昼夜节律控制，可以使地面臭氧的模型预测与测量结果更加一致，特别是在世界上对异戊二烯敏感的地区。
The volatile organic compound isoprene is produced by many plant species, and provides protection against biotic and abiotic stresses. Globally, isoprene emissions from plants are estimated to far exceed anthropogenic emissions of volatile organic compounds. Once in the atmosphere, isoprene reacts rapidly with hydroxyl radicals to form peroxy radicals, which can react with nitrogen oxides to form ground-level ozone. Here, we use canopy-scale measurements of isoprene fluxes from two tropical ecosystems in Malaysia—a rainforest and an oil palm plantation—and three models of atmospheric chemistry to explore the effects of isoprene fluxes on ground-level ozone. We show that isoprene emissions in these ecosystems are under circadian control on the canopy scale, particularly in the oil palm plantation. As a result, these ecosystems emit less isoprene than present emissions models predict. Using local-, regional- and global-scale models of atmospheric chemistry and transport, we show that accounting for circadian control of isoprene emissions brings model predictions of ground-level ozone into better agreement with measurements, especially in isoprene-sensitive regions of the world.