Department of Environmental Science, Policy, and Management, University of California at Berkeley, Berkeley, CA 94720, USA.
Science. 2013 Aug 9;341(6146):643-7. doi: 10.1126/science.1235053.
Numerous volatile organic compounds (VOCs) exist in Earth's atmosphere, most of which originate from biogenic emissions. Despite VOCs' critical role in tropospheric chemistry, studies for evaluating their atmosphere-ecosystem exchange (emission and deposition) have been limited to a few dominant compounds owing to a lack of appropriate measurement techniques. Using a high-mass resolution proton transfer reaction-time of flight-mass spectrometer and an absolute value eddy-covariance method, we directly measured 186 organic ions with net deposition, and 494 that have bidirectional flux. This observation of active atmosphere-ecosystem exchange of the vast majority of detected VOCs poses a challenge to current emission, air quality, and global climate models, which do not account for this extremely large range of compounds. This observation also provides new insight for understanding the atmospheric VOC budget.
在地球大气中存在着大量的挥发性有机化合物（VOCs），其中大部分来源于生物排放。尽管 VOCs 在对流层化学中起着至关重要的作用，但由于缺乏适当的测量技术，评估它们在大气-生态系统交换（排放和沉积）方面的研究仅限于少数几种主要化合物。我们使用高分辨率质子转移反应-飞行时间质谱仪和绝对值涡度协方差方法，直接测量了 186 种具有净沉积的有机离子和 494 种具有双向通量的有机离子。这种对绝大多数已检测到的 VOC 进行的活跃的大气-生态系统交换的观测，对当前的排放、空气质量和全球气候模型提出了挑战，因为这些模型没有考虑到如此广泛的化合物范围。这一观测结果也为理解大气 VOC 预算提供了新的认识。
