SGER: Investigations of Cloud Condensation Nuclei

SGER：云凝聚核的研究

• 批准号: 0122493
• 负责人: Glenn Shaw
• 金额: $ 5万
• 依托单位: University of Alaska Fairbanks Campus
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2001
• 资助国家: 美国
• 起止时间: 2001-08-01 至 2003-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0122493&HistoricalAwards=false
• 关键词: SGER; Investigations; Cloud; Condensation; Nuclei

This is a Small Grant for Exploratory Research (SGER) to support research on the physical and chemical properties of cloud condensation nuclei. The experiments will be conducted in the winter of 2001-02 at two, or possibly three, mountaintop observatories in the southwestern United States. Central to the experiment is a novel instrument called the Cloud Condensation Nuclei Remover (CCNR). It is a thermal gradient diffusion chamber through which an air sample is slowly drawn. It flows as a thin, laminar ribbon between two saturated plates having different temperatures. The supersaturation at the center of the chamber is regulated by adjusting the temperatures of the plates. Depending on the supersaturation, some of the aerosols in the sample are activated, grow, and settle out as droplets on the bottom of the chamber as the air moves through. The size distribution of the surviving particles is compared with that of the particles entering the chamber to determine the sizes of the particles that served as centers for cloud condensation. By comparing electron microscope images and the chemical composition of the particles before and after exposure to the supersaturation it may be possible to learn more about the aerosol particles that are active in cloud formation. The project is designed to resolve the discrepancies that currently exist between observations of the physical and chemical properties of aerosol particles and their cloud-forming ability.

这是一项探索性研究小额补助金（SGER），用于支持云凝结核的物理和化学性质的研究。 实验将于2001-02年冬季在美国西南部的两个或三个山顶观测站进行。 实验的核心是一种名为云凝聚核清除器（CCNR）的新型仪器。 它是一个热梯度扩散室，空气样品通过它被缓慢地抽取。 它在具有不同温度的两个饱和板之间以薄层流带的形式流动。 通过调节板的温度来调节腔室中心的过饱和度。 根据过饱和度，样品中的一些气溶胶被激活，生长，并随着空气移动而在室底部沉降为液滴。 幸存粒子的尺寸分布与进入室的粒子的尺寸分布进行比较，以确定作为云凝结中心的粒子的尺寸。 通过比较电子显微镜图像和暴露于过饱和之前和之后的颗粒的化学成分，可以更多地了解在云形成中活跃的气溶胶颗粒。 该项目旨在解决目前对气溶胶粒子的物理和化学性质及其成云能力的观测之间存在的差异。