EAGER: Nanoparticle Growth from Salting-in and Mobile Infrared Column Observations

EAGER：盐溶和移动红外柱观察中纳米颗粒的生长

• 批准号: 1452317
• 负责人: Rainer Volkamer
• 金额: $ 25.89万
• 依托单位: University of Colorado at Boulder
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2014
• 资助国家: 美国
• 起止时间: 2014-09-01 至 2017-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1452317&HistoricalAwards=false
• 关键词: EAGER; Nanoparticle; Growth; Salting; Mobile

This research includes the development of a new mobile instrument for providing data on the column absorption of infrared radiation by hydrocarbons in the atmosphere, a process that can lead to an atmospheric warming. The Principal Investigator of the project also has been invited to visit the Paul-Scherrer Institute in Switzerland to design a series of experiments at the CLOUD chamber facility at CERN. This facility will enable him to study the formation of secondary organic aerosol (SOA) in the atmosphere under varying conditions of ambient temperature and pressure. It is important to understand the mechanisms that lead to the fast formation and growth of secondary organic aerosol since they are important in predicting air quality and climate change.The proposed CLOUD chamber experiments will focus on the 'salting-in' effect as a mechanism for explaining accelerated nanoparticle growth rates. In the case of glyoxal, 'salting-in' consists of the displacement of water molecules from the hydration shell of sulfate ions by hydrated glyoxal molecules. Preliminary studies show efficient growth from glyoxal at relative humidity (RH) of up to 20% for highly acidic nanoclusters. However, there are currently no experimental data available at RH above 20% and for neutral nanoclusters, where the multiphase chemistry is expected to proceed via different pathways. The proposed research will address the following questions related to the formation of SOA (associated with glyoxal) in the atmosphere: (1) What is the 'threshold cluster size' at which glyoxal begins to assists with the stabilization/growth of clusters; and (2) How does the growth rate of stable clusters depend on relative humidity and pH? The 'salting-in' mechanism has been incorporated in an atmospheric model to successfully explain the fast formation of SOA from glyoxal that was observed in a recent NSF-supported field campaign to study air pollution in Mexico City.The development of the mobile Solar Occultation Flux instrument and the acquisition of new expertise for IR retrievals from the instrument will offer a novel way to better quantify atmospheric composition and changes in composition. The experiments at the CLOUD chamber may result in transformative research on the mechanisms for formation and growth of secondary organic aerosol. This research is funded through the EArly-concept Grants for Exploratory Research (EAGER) program.

这项研究包括开发一种新的移动仪器，用于提供大气中碳氢化合物对红外辐射的柱吸收的数据，这一过程可能导致大气变暖。该项目的主要调查员还被邀请参观瑞士的Paul-Scherrer Institute，在CERN的Cloud Chamber设施中设计了一系列实验。该设施将使他能够研究在不同环境温度和压力条件下大气中次生有机气溶胶（SOA）的形成。重要的是要了解导致二级有机气溶胶快速形成和生长的机制，因为它们在预测空气质量和气候变化方面很重要。拟议的云腔实验将集中于“盐分盐”效应，作为解释加速纳米粒子生长速率的机制。在乙二醛的情况下，“盐水”由水分子从硫酸盐离子的水合壳中的位移组成。初步研究表明，高度酸性纳米簇的相对湿度（RH）的乙二醇的有效生长高达20％。但是，目前尚无RH高于20％的实验数据，对于中性纳米簇，预计多相化学将通过不同的途径进行。拟议的研究将解决与大气中SOA形成（与乙二醇相关的）有关的以下问题：（1）乙二醇开始有助于糖的稳定/簇生长的“阈值簇大小”是什么？ （2）稳定簇的生长速率如何取决于相对湿度和pH？ “盐水”机制已纳入了大气模型中，以成功地解释了在最近的NSF支持的现场运动中观察到的SOA的快速形成，以研究墨西哥城的空气污染。移动太阳能模仿仪器的开发以及从仪器中获得IR的新专业知识，可以更好地构成IR的新专业知识。云腔的实验可能会导致对次生有机气溶胶形成和生长机制的变革性研究。这项研究是通过探索性研究（急切）计划的早期概念赠款资助的。