Collaborative Research: VOCALS--Interaction of Aerosols with Marine Boundary Layer Clouds

这项研究将侧重于物理和化学分析的环境气溶胶和残留云滴核获得的NSF C-130飞机在东南太平洋（SEP）在2008年VOCALS-REx（VAMOS海洋-云-大气-陆地研究区域实验）项目。 这项工作解决了以下VOCALS假设：1）气溶胶性质的变化影响SEP上空层积云中毛毛雨的形成; 2）SEP上空小的气溶胶半径主要受人为而非自然气溶胶的控制，来自低层自由对流层的污染空气的卷吸是云凝结核（CCN）的重要来源;海洋上升流影响气溶胶前体气体和气溶胶粒径分布在大气边界层的SEP。为了探讨这些假设，云液滴的残留核的大小和化学成分将被测量后采样与逆流虚拟撞击器（CVI），分离液滴从间隙气溶胶和蒸发它们。 云外的气溶胶将用撞击器取样。 将通过电子显微镜和X射线分析对残留核和环境气溶胶的过滤器和撞击器样品进行分析。 这些数据将与云的微物理测量相结合，以确定气溶胶对云的光学特性和寿命的影响以及使云滴成核的气溶胶粒子的特性。 较大水滴的核，引发毛毛雨的生产，也将被探索。 这些测量将补充VOCALS中其他研究人员的观察结果。这项工作将导致深入了解由于人类活动产生的气溶胶如何影响降水和云对地球气候的辐射影响。 教育计划包括一名本科生和一名博士后学者，他们将与研究人员一起分析和解释收集的数据。

This study will focus on physical and chemical analysis of ambient aerosol and residual cloud droplet nuclei obtained from the NSF C-130 aircraft over the southeast Pacific (SEP) during the 2008 VOCALS-REx (VAMOS Ocean-Cloud-Atmosphere-Land Study Regional Experiment) project. This work addresses the following VOCALS hypotheses: 1) Variability in aerosol properties impacts the formation of drizzle in stratocumulus clouds over the SEP, 2) The small aerosol radii over the SEP are primarily controlled by anthropogenic, rather than natural, aerosol production, and entrainment of polluted air from the lower free troposphere is an important source of cloud condensation nuclei (CCN), and 3) Ocean upwelling affects aerosol precursor gases and the aerosol size distribution in the atmospheric boundary layer over the SEP. To explore these hypotheses, the size and chemical composition of residual nuclei in cloud droplets will be measured following sampling with a counterflow virtual impactor (CVI), which separates droplets from interstitial aerosol and evaporates them. Aerosols outside of clouds will be sampled with an impactor. Filter and impactor samples of residual nuclei and ambient aerosol will be analyzed by electron microscopy with X-ray analysis. These data will be combined with cloud microphysical measurements to determine aerosol effects on cloud optical properties and lifetimes and the characteristics of aerosol particles that nucleate cloud droplets. Nuclei of larger droplets, which initiate drizzle production, will also be explored. These measurements will complement observations being made by other investigators in VOCALS. This work will lead to insight into how aerosol production due to human activity influences precipitation and the radiative impact of clouds on Earth's climate. The educational plans include an undergraduate student and postdoctoral scholar who will work with the investigators to analyze and interpret the data collected.