Biogenic Organic Aerosol Experiment in Amazonia

在雨季，亚马逊雨林是一个很大程度上不受干扰的系统，就积累模式形成的生物气溶胶而言。本研究将进一步描述在原始环境下天然二次有机气溶胶（SOA）的形成、加工和云形成特性。由于植物排放物（如异戊二烯、单萜烯）和大气氧化剂的光反应，SOA的大小决定了颗粒演变成更大的云凝结核（CCN），可能通过由此产生的降水模式的控制，在生物过程和气候之间发挥机制联系。实地调查将利用一个现有的森林研究地点，即位于玛瑙斯以北60公里处的亚马逊大型生物圈-大气实验（LBA）塔。玛瑙斯是巴西亚马逊州的首府，拥有约200万人口。主要的实验策略将集中在高（质量）分辨率飞行时间气溶胶质谱仪（HR ToF-AMS）的部署上，该质谱仪将允许在高时间分辨率下观察大气质量负载，质谱（化学鉴定）和SOA颗粒的气动尺寸分布（35nm至1.5um）。

During the wet season, the Amazon rainforest is a largely unperturbed system with respect to the formation of accumulation mode biogenic aerosols. This study will further describe the formation, processing and cloud forming properties of natural secondary organic aerosols (SOA) in a pristine setting. Arising from the photoreaction of vegetative emissions (e.g., isoprene, monoterpenes) and atmospheric oxidants, the size resolved particulate evolution of SOA into larger, cloud condensation nuclei (CCN) potentially serves as a mechanistic link between biological processes and climate through resulting control of precipitation patterns. Field investigations will take advantage of an existing forest research site, the Large Scale Biosphere-Atmosphere Experiment in Amazonia (LBA) tower site located 60km north of Manaus, a city of approximately 2 million and the capital of Amazonas state, Brazil. The prime experimental strategy will concentrate on the deployment of a high (mass) resolution time-of-flight aerosol mass spectrometer (HR ToF-AMS) which will allow the atmospheric mass loading, the mass spectra (chemical identification) and the aerodynamic size distribution (35nm to 1.5um) of SOA particles to be observed at high temporal resolution.