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的仪器，提供大气中碳氢化合物对红外辐射柱吸收的数据，这一过程可能导致大气变暖。该项目的首席研究员还应邀访问了瑞士的Paul-Scherrer研究所，在欧洲核子研究中心的云室设施设计了一系列实验。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二次有机气溶胶（SOA）的形成。重要的是要了解导致二次有机气溶胶快速形成和增长的机制，因为它们在预测空气质量和气候变化方面很重要。拟议的云室实验将集中在“盐溶”效应上，作为解释纳米颗粒加速增长速率的机制。在乙二醛的情况下，“盐溶”由水合乙二醛分子从硫酸根离子的水合壳层置换水分子组成。初步研究表明，高酸性纳米团簇在相对湿度（RH）高达20%的乙二醛有效的增长。然而，目前没有实验数据可在RH高于20%和中性纳米团簇，其中多相化学预计将通过不同的途径进行。拟议的研究将解决以下与大气中SOA（与乙二醛相关）形成相关的问题：（1）乙二醛开始帮助团簇稳定/生长的“阈值团簇大小”是多少;（2）稳定团簇的生长速度如何取决于相对湿度和pH值？“盐溶”机制已被纳入大气模型中，以成功解释最近NSF-中观察到的由乙二醛快速形成SOA的现象。移动的太阳掩星通量仪器的开发和从该仪器获得红外线反演的新专门知识，将提供一种新的方法，更好地量化大气成分和混合物. CLOUD室的实验可能会导致对二次有机气溶胶形成和增长机制的变革性研究。这项研究是通过早期概念的探索性研究（EAGER）计划赠款资助。