RONOCO (ROle of Nighttime chemistry in controlling the Oxidising Capacity of the AtmOsphere)

现在有越来越多的重要证据表明，主要由硝酸根NO3驱动的夜间化学在控制对流层组成方面起着重要作用。最近的发现表明，在远离地球表面的地方存在高浓度的NO3。在受污染的环境中，主汇丰富，但这也是它形成最快的地方，因此NO3的周转时间非常快。这种行为的重要性尚不清楚，但它可能对大气化学和臭氧形成、氧化氮的区域运输和转化以及酸化和富营养化产生非常大的影响，并可能显著增加硝酸铵颗粒的区域负担，这对气候的重要性日益增加。为了正确地理解和预测这些现象，需要量化控制NO3及其从大气中去除的基本化学过程；NO3化学对挥发性有机碳化学的影响及其作为自由基形成和传播的途径；其非均相化学性质及其对气溶胶负荷和组成的影响；它对区域和全球尺度臭氧形成的影响及其对氧化氮大气生命周期的调解作用。提出了一个联合项目，利用仪器开发、机载测量、详细过程建模以及区域和全球建模的综合方案来解决这些耦合问题。主要交付成果将包括：1增强FAAM飞机的仪器能力，包括NO3和N2O5的测量。2在一系列条件下对夜间自由基、其源和汇以及边界层和自由对流层气溶胶组成的综合测量。控制夜间化学过程的关键过程的量化。评估夜间化学对区域尺度的影响。5 .评估夜间化学对当前和未来大气的全球影响。

There is now a significant and increasing body of evidence that night time chemistry, driven primarily by the nitrate radical NO3, plays a significant role in governing the composition of the troposphere. Recent findings show that very high concentrations of NO3 are present away from the Earth's surface. In polluted environments, the main sinks are abundant but this is also where its formation may be most rapid and hence the NO3 turnover time is very fast. The importance of this behaviour is not as yet clearly understood, yet it may have a very large impact on atmospheric chemistry and ozone formation, regional transport and transformation of oxidised nitrogen and hence acidification and eutrophication, and may also significantly add to the regional burden of ammonium nitrate particulate, which has increasing climatic importance. To understand and predict these phenomena correctly there is a need to quantify the basic chemical processes controlling NO3 and its removal from the atmosphere; the impact of NO3 chemistry on volatile organic carbon chemistry and as a pathway for radical formation and propagation; its heterogeneous chemistry and its impact on the aerosol burden and composition; its influence on ozone formation on regional and global scales and its mediation of the atmospheric lifecycle of oxidised nitrogen. A consortium project is proposed that addresses these coupled questions using a combined programme of instrument development, airborne measurement, detailed process modelling, and regional and global modelling. The principal deliverables will be: 1 Enhancements to the instrumental capability of the FAAM aircraft to include measurements of NO3 and N2O5. 2 Comprehensive measurements of night time radicals, their sources and sinks, and aerosol composition in the boundary layer and free troposphere in a range of conditions. 3 Quantification of the key processes which control night-time chemical processes. 4 Assessment of the impacts of night-time chemistry on regional scales. 5 An assessment of the global impacts of night-time chemistry in the current and future atmospheres.