RAPID: Measurements of Hydroxyl Radicals, Sulfuric Acid, sCIs, Hydroperoxy Radicals and Organic Peroxy Radicals on the C-130 during FRAPPE

这项工作涉及在美国国家科学基金会/国家航空航天研究中心C-130飞机平台上部署一个四通道化学电离质谱仪（CIMS）系统，该系统将于2014年7月16日至8月16日在科罗拉多北方前靶场大都市区进行前靶场空气污染和光化学实验（FRAPPE）现场活动。FRAPPE是一项由国家大气研究中心（NCAR）的研究人员领导的运动，许多大学科学家参与其中。FRAPPE活动将与NASA DISCOVER-AQ同时进行（从与空气质素有关的柱状及垂直解析观测资料中获取地面情况资料）计划。透过这项工作所量度的化学种类包括（羟基），HO 2（过氧化氢自由基）和HO 2 + RO 2（氢过氧加有机过氧自由基）、H2SO 4（硫酸）和sCl（来自烯烃与臭氧- O3反应的稳定Criegee自由基中间体的总和）。这些测量将改善活动期间采样空气团氧化能力的空间和时间变化的特性。它们还将有助于限制硫酸在气溶胶形成和增长中的作用，并量化sCI在城市环境中作为氧化剂的重要性。羟基自由基（OH）是低层大气中的主要氧化剂，也是导致臭氧形成的最重要的氧化剂。在这项研究中所做的测量将作出重要贡献的空气质量建模和预测，并在确定臭氧的来源在科罗拉多北方前山脉大都市区。这一努力预计将导致改进的模型表示的化学过程中发生的城市环境。

This effort involves the deployment of a four-channel chemical ionization mass spectrometer (CIMS) system on the NSF/NCAR C-130 aircraft platform during the Front Range Air Pollution and Photochemistry Experiment (FRAPPE) field campaign scheduled to take place from July 16-August 16, 2014 in the Colorado Northern Front Range Metropolitan Area. FRAPPE is a campaign being lead by researchers from the National Center for Atmospheric Research (NCAR), with the participation of many university scientists. The FRAPPE campaign will run concurrently with the NASA DISCOVER-AQ (Deriving Information on Surface conditions from Column and Vertically Resolved Observations Relevant to Air Quality) project.Chemical species to be measured through this effort include OH (hydroxyl radicals), HO2 (hydroperoxy radicals) and HO2+RO2 (hydroperoxy plus organic peroxy radicals), H2SO4 (sulfuric acid), and sCIs (the sum of stabilized Criegee radical Intermediates from the reactions of alkenes with ozone - O3). These measurements will improve characterization of the spatial and temporal variability of the oxidizing capacity of the sampled air masses during the campaign. They will also help to constrain the role of sulfuric acid in aerosol formation and growth, and quantify the importance of sCIs as an oxidant in the urban environment.The hydroxyl radical (OH) is the main oxidant in the lower atmosphere and the most significant one causing the formation of ozone. The measurements made in this study will make a vital contribution to modeling and forecasting air quality and in determining the sources of ozone in the Colorado Northern Front Range Metropolitan area. This effort is expected to lead to improved model representations of chemical processes occurring in the urban environment.