Direct Studies of Peroxy Radical Autoxidation Reactions

生物来源的挥发性有机化合物(BVOCs)通过设定大气中气溶胶的本底水平，在气候变化中起着至关重要的作用。气溶胶直接或间接地与太阳辐射相互作用，影响气候。BVOCs还通过形成臭氧等二次污染物在空气质量中发挥关键作用，这些二次污染物会对人类和植物造成不利影响。过氧自由基(RO2)是参与这些物理化学过程的关键中间体，其形成具有无数的结构差异，预计这些差异将极大地影响它们的反应活性和形成气溶胶和臭氧的途径。然而，直到最近在近红外光腔衰荡光谱方面取得突破，才能了解RO2结构和反应性的分布，从而不可能了解对气溶胶和臭氧的影响。在这里，我们提出了一个实验室和地球系统相结合的模拟项目，该项目将从最重要的BVOCs(异戊二烯和α-蒎烯)中确定RO2的关键物理化学性质，并通过开发和纳入化学机制来整合这一知识，这些化学机制将被用来比以往任何时候都更真实地模拟BVOCs的气候影响。该项目的成果将直接惠及大气和物理科学领域的学术研究人员以及规划近期和长期环境和气候变化的政策制定者。这个项目将使Rabi Chhantyal Pun博士能够在剑桥大学亚历山大·阿奇博尔德博士的建模支持下，在诺丁汉大学启动一个专注于实验室光化学的新研究计划。它还将为一名新的博士后研究助理提供最先进的实验室和大气化学培训。

Biogenic volatile organic compounds (BVOCs) play a crucial role in climate by setting the background levels of aerosol in the atmosphere. Aerosols directly and indirectly interact with solar radiation and affect climate. BVOCs also play a crucial role in air quality through forming secondary pollutants like O3 which adversely affect humans and plants. Peroxy radicals (RO2) are key intermediates involved in these physio-chemical processes and are formed with myriad structural differences which are predicted to greatly affect their reactivity and pathways to form aerosols and O3. However, until the recent breakthroughs in near infrared cavity ring-down spectroscopy understanding the distribution of RO2 structures and reactivity, and so the effects on aerosols and O3, was impossible. Here we propose a combined laboratory and Earth system modelling project which will determine the key physio-chemical properties of RO2 from the most important BVOCs (isoprene and alpha-pinene) and integrate this knowledge through the development and incorporation of chemical mechanisms that will be used to simulate the climate impacts of BVOCs more faithfully than ever possible before. The results from this project will be of direct benefit to academic researchers in atmospheric and physical sciences and policy makers planning for the environmental and climate changes in the near and long-term future. This project will enable Dr Rabi Chhantyal Pun to start a new research program focused on laboratory photochemistry at the University of Nottingham, with modelling support from Dr Alexander Archibald at the University of Cambridge. It will also provide state-of-art laboratory and atmospheric chemistry training for a new postdoctoral research associate.