Airborne Measurements of Inorganic Acids during the Deep Convective Clouds and Chemistry (DC3) Experiment

深层对流云和化学（DC3）野外活动旨在描述对流系统对对流层上层（UT）的化学和组成的影响。本项目支持在NSF/NCAR G-V飞机上部署一台新建的化学电离质谱仪（CIMS），用于测量过硝酸（HO2NO2）、硝酸（HNO3）、盐酸（HCl）和二氧化硫（SO2）。这些观测结果将被解释以评估对流对UT光化学的影响。在对流流出物内部和周围测量的HNO3和HO2NO2将为这些环境中的化学过程提供有价值的约束。HO2NO2的观测将特别有用，因为该物种相对较短的寿命使其对自由基水平非常敏感。光化学计算将用于预测观测到的HO2NO2水平以及观测到的HNO3的时间演变。这将对我们对控制UT自由基水平和臭氧产生的过程的理解进行关键测试。对二氧化硫的观测将用于评估该物种的云处理过程，并作为与DC3中涉及的其他飞机的有用比较点。HCl观测将作为平流层影响的示踪剂，并为低空中大陆氯化学提供一个标记。通过这个项目产生的信息将提高对对流风暴对大气化学影响的认识。此外，CIMS仪器将成为NCAR设施的一部分，供未来的G-V研究人员使用。该项目将支持一名博士生，并构成其论文研究的核心。两名本科生将通过参与该项目获得宝贵的研究经验。最后，PI将与亚特兰大当地的一所高中合作，促进代表性不足的少数民族接受高等教育和科学研究。

The Deep Convective Clouds and Chemistry (DC3) field campaign seeks to characterize the impact of convective systems on the chemistry and composition of the upper troposphere (UT). This project supports the deployment of a newly built chemical ionization mass spectrometer (CIMS) on the NSF/NCAR G-V aircraft to measure pernitric acid (HO2NO2), nitric acid (HNO3), hydrochloric acid (HCl), and sulfur dioxide (SO2). These observations will be interpreted to evaluate the impact of convection on UT photochemistry. HNO3 and HO2NO2 measured in and around convective outflow will provide valuable constraints on the chemical processes in these environments. The HO2NO2 observations will be particularly useful as the relatively short lifetime of this species makes it very sensitive to radical levels. Photochemical calculations will be performed to predict the observed HO2NO2 levels as well as the time evolution of the observed HNO3. This will allow a critical test of our understanding of processes that control radical levels and ozone production in the UT. Observations of SO2 will be used to assess the cloud processing of this species and serve as a useful comparison point with other aircraft involved in DC3. The HCl observations will serve as a tracer for stratospheric influence and provide a marker for lower altitude mid-continent chlorine chemistry. The information generated through this project will improve understanding of the impacts of convective storms on atmospheric chemistry. In addition, the CIMS instrument will become part of the facilities at NCAR and available for future investigators on the G-V. The project will support one Ph.D. student and form the core of his/her dissertation research. Two undergraduate students will gain valuable research experience through participation in the project. Finally, the PI will partner with a local Atlanta area high school to facilitate exposure of underrepresented minorities to higher education and scientific research.