Physical and Chemical Properties of Aerosols in the Marine Boundary Layer

9619984本项目侧重于海洋气溶胶粒子的吸湿特性，以了解和确定海洋边界层气溶胶粒子的物理、光学和云成核特性。气溶胶的吸湿特性与大气相对湿度f(RH)有关。这些特性是影响传输过程中气溶胶物理和光学特性的空间和时间变异性的关键因素。该项目是北大西洋区域气溶胶特性实验(ACE-2)的一部分，该实验将于1997年6月和7月在亚热带东北大西洋上空进行，作为一项国际合作努力。ACE-2的主要目标是利用飞机、船载和地面测量来研究与辐射强迫和气候变化有关的大气气溶胶特性。这些测量将涉及使用能够测量海洋边界层气溶胶颗粒的吸湿增长特性的串联式差动流度分析仪(RH-TDMA)。PI将比较周围颗粒物和实验室制备的合成气雾剂的吸湿性，这些气雾剂的化学成分包括人造海水、源自海水溶液的气溶胶、酸性硫酸盐和海藻的内部混合物以及酸性硫酸盐、硝酸盐和有机酸的内部混合物。实验室研究将用于解释在大型ACE-2现场试验期间测量的海洋边界层气溶胶和人为气溶胶的增长情况。该项目将提供必要的资料，以评估通过测量海洋边界层中的颗粒大小分布和吸湿性，能够以何种确定性预测光散射和云凝结核的数量。改善气溶胶物理和光学性质之间的联系是量化大气中的气溶胶粒子的直接和间接辐射效应的必要步骤。自动柜员机-9619984

9619984 Covert This project focuqes on the hygroscopic properties of marine aerosol particles in order to understand and to determine the physical, optical and cloud nucleating properties of marine boundary layer aerosol particles. The hygroscopic properties of aerosol are related to atmospheric relative humidity f(RH) . These properties are key factors that influence the spatial and temporal variability of the aerosol physical and optical properties during transport. The project is part of the North Atlantic Regional Aerosol Characterization Experiment (ACE-2) which will be conducted in June and July, 1997, over the subtropical Northeastern Atlantic Ocean as an international collaborative effort. The main objectives of ACE-2 are to study the properties of atmospheric aerosols that are relevant to radiative forcing and climate change using aircraft, ship-board, and ground-based measurements. The measurements will involve use of a tandem differential mobility analyzer (RH-TDMA) that is capable of measuring the hygroscopic growth properties of marine boundary layer aerosol particles. The PI will compare the hygroscopic behavior of ambient particles with those of synthetic aerosol prepared in the laboratory and having chemical compositions of artificial seawater, aerosol derived from sea water solutions, internal mixtures of acid sulfate and seasalt and internal mixtures of acid sulfate, nitrate and organic acids. The laboratory studies will be used to interpret the growth of marine boundary layer aerosols and anthropogenic aerosols measured during the large-scale ACE-2 field experiment. The project will develop information needed to evaluate with what certainty light scattering and numbers of cloud condensation nuclei can be predicted from measurements of particle size distributions and hygroscopicity in the marine boundary layer. Improving the linkage between aerosol physical and optical properties is a necessary step for quantifying the direct and indirect radiative effects of a erosol particles within the atmosphere. ATM-9619984