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

合作研究：VOCALS——气溶胶与海洋边界层云的相互作用

• 批准号: 0746685
• 负责人: Cynthia Twohy
• 金额: $ 18.74万
• 依托单位: Oregon State University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2008
• 资助国家: 美国
• 起止时间: 2008-05-01 至 2012-04-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0746685&HistoricalAwards=false
• 关键词: Collaborative; Research; VOCALS; Interaction; Aerosols

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.

本研究的重点是在2008年VOCALS-REx （VAMOS海洋-云-大气-陆地研究区域实验）项目中，由美国国家科学基金会C-130飞机在东南太平洋（SEP）上空获得的环境气溶胶和残余云滴核的物理和化学分析。这项工作解决了以下VOCALS假说：(1)气溶胶特性的变化影响了平流层积云中毛毛雨的形成；(2)平流层上空气溶胶的小半径主要受人为而非自然气溶胶产生的控制，低层自由对流层污染空气的夹带是云凝结核（CCN）的重要来源。3)海洋上升流影响气溶胶前体气体和气溶胶在SEP上空大气边界层中的大小分布。为了探索这些假设，将使用逆流虚拟冲击器（CVI）采样后测量云滴中残余核的大小和化学组成，该虚拟冲击器将液滴从间隙气溶胶中分离并蒸发。云外的气溶胶将用撞击器取样。过滤器和撞击器的残余核和周围气溶胶样品将用电子显微镜和x射线分析进行分析。这些数据将与云微物理测量相结合，以确定气溶胶对云光学特性和寿命的影响，以及形成云滴的气溶胶颗粒的特征。更大的液滴核，引发毛毛雨的产生，也将被探索。这些测量结果将补充VOCALS中其他研究人员的观察结果。这项工作将有助于深入了解由于人类活动而产生的气溶胶如何影响降水和云对地球气候的辐射影响。该教育计划包括一名本科生和一名博士后学者，他们将与调查人员一起分析和解释收集到的数据。