Chemical Pathways Leading to Organic Aerosol Formation from the Atmospheric Oxidation of Alkanes and Alkenes

加州大学河滨分校的研究人员将继续对非甲烷烃(NMHC)的烷烃和烯烃的氧化途径进行系统的实验室研究，这些非甲烷烃来自自然和人为来源，存在于城市和偏远的对流层空气中。特别是烷烃组分构成了城市大气中存在的NMHC的最大已知质量分数。然而，这些化合物与主要的大气氧化剂如OH、NOx和臭氧的反应活性较低，而且与异戊二烯和芳烃等活性较高的化合物相比，对它们向二次有机气溶胶(SOA)的氧化转化的研究较少。由NMHC的低蒸汽压反应产物和挥发性有机化合物(VOC)凝结而成的SOA，是我们理解细颗粒物(PM2.5；直径小于2.5微米的颗粒物)的化学、生理学和流行病学的关键因素，与大气气溶胶的健康影响有关。SOA对能见度和全球气候也有影响。

Researchers from UC Riverside will continue systematic laboratory based investigations of the oxidation pathways of the alkane and alkene fractions of the non-methane hydrocarbons (NMHC) arising from natural and anthropogenic sources and found in urban and remote tropospheric air. The alkane fraction in particular constitutes the largest known mass fraction of NMHC present in urban atmospheres. However, these compounds exhibit a lower general reactivity with key atmospheric oxidants such as OH, NOx and ozone and their oxidative conversation to secondary organic aerosols (SOA) has been less comprehensively studied than more reactive compounds such as isoprene and aromatics. SOA, resulting from the condensation of low vapor pressure reaction products of NMHCs and volatile organic compounds (VOCs), are a key factor in our understanding the chemistry, physiology and epidemiology of the fine particulate matter (PM 2.5; particulate matter less than 2.5 microns in diameter) implicated in the health impacts of atmospheric aerosols. SOA also have effects on visibility and global climate.