Formation of Urban Ultrafine Particles in Houston

该项目重点研究可能导致城市大气中超细颗粒物形成的大气过程。了解超细颗粒的形成非常重要，因为它们在肺部具有更高的穿透和沉积效率，并且比大颗粒具有更高的毒性。它们还可以增强云凝结核的产生。这项研究与更好地了解气候和空气质量问题有关，特别是在城市地区。计划开展两个为期6周的实地活动，利用一套最先进的气溶胶和化学仪器测量化学前体，如高氧分子，以及颗粒大小和化学成分。实地工作将在休斯敦大都市地区进行，因为该地区炼油厂、发电厂、航道、城市和海洋排放的气溶胶和气相前体的排放种类繁多。要解决的主要科学问题是：(1)交通排放和新颗粒物形成对休斯敦城市超细颗粒物的相对贡献是什么？(2)在不同温度和NOx(NO+N02)条件下，城市HOMS(高度氧化的有机分子)的分子组成是什么？(3)不同的化学前体如何促进城市新颗粒物的形成，如硫酸、氨、胺和休斯敦的HOMS？这项研究将支持两名女性教职员工和几名研究生。这一奖项反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。

This project focuses on atmospheric processes that can lead to the formation of urban ultrafine particles in the urban atmosphere. Understanding the formation of ultrafine particles is important because they have higher penetration and deposition efficiencies in the lung and have higher toxicity than larger particles. They can also enhance the production of cloud condensation nuclei. This research is relevant for better understanding climate and air quality issues, particularly in urban areas.Two 6-week field campaigns are planned for measuring chemical precursors such as highly oxygenated molecules, and particle sizes and chemical composition with a suite of state-of-the-art aerosol and chemical instrumentation. The field work will be conducted in the metropolitan Houston area due to the variety of emissions for aerosol and gas-phase precursors from oil refineries, power plants, ship channels, urban and marine emissions in the region. The main scientific questions to be addressed are: (1) What is the relative contribution of traffic emissions vs. new particle formation to the urban ultrafine particles in Houston? (2) What is the molecular composition of urban HOMs (highly oxygenated organic molecules) under different temperatures and NOx (NO+N02) conditions? (3) How is urban new particle formation facilitated by different chemical precursors, such as sulfuric acid, ammonia, amines, and HOMs in Houston? This research will support two female faculty members and several graduate students.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.