Improving Chemical Mechanisms of Reactive Nitrogen from Snowpack and Transportation in a Global Chemical Transport Model

该奖项全部或部分由《2021年美国救援计划法案》（公法117-2）资助。该项目的目标是改善与积雪排放的氮氧化物（NOx）和硝酸（HONO）以及道路汽油和柴油部门排放的HONO相关的化学机制。PI假设积雪中硝酸盐气溶胶的光解作用（阳光的反应）导致大气中NOx和HONO的产生。这项工作将改进美国臭氧生成和空气质量的模型。该提案的目标是：(1)参数化与积雪排放相关的NOx/HONO化学机制，以及与公路汽油和柴油子行业排放相关的HONO化学机制，并在全球GEOS-Chem化学运输模型中实施这些机制；(2)量化全球积雪和交通运输中道路汽油和柴油分部门NOx/HONO生产来源缺失对大气氧化剂和空气质量的影响。GEOS-Chem中更新的NOx/HONO化学机制将根据全球地表HONO和二氧化氮（NO2）观测数据以及卫星观测的对流层NO2柱密度测量数据进行评估。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

This award is funded in whole or in part under the American Rescue Plan Act of 2021 (Public Law 117-2). The goal of this project is to improve the chemical mechanisms associated with emissions of global nitrogen oxides (NOx) and nitrous acid (HONO) from snowpack and HONO from the on-road gasoline and diesel sectors. The PI hypothesizes that the photolysis (reaction by sunlight) of nitrate aerosols in the snowpack leads to the production of NOx and HONO in the atmosphere. This work will improve the modeling of ozone production and air quality in the US.The objectives of this proposal are to (1) parameterize representations of the NOx/HONO chemical mechanisms associated with snowpack emissions, and HONO chemical mechanisms associated with on-road gasoline and diesel subsector emissions and implement these in the global GEOS-Chem chemical transport model; and (2) quantify the impacts of global missing sources of NOx/HONO production from snowpack, and on-road gasoline and diesel subsectors in transportation on atmospheric oxidants and air quality. The updated NOx/HONO chemical mechanisms in GEOS-Chem will be evaluated against global surface HONO and nitrogen dioxide (NO2) observations, as well as tropospheric NO2 column density measurements from satellite observations.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.