Role of Ice in High Latitude Nitrogen Atmospheric Chemistry

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This award is funded under the American Recovery and Reinvestment Act of 2009 (Public Law 111-5).This project will study the processes that remove nitrogen oxides in high latitudes during winter by measuring near-surface nocturnal nitrogen oxide levels, quantifying their lifetimes through a steady-state analysis, and correlating their loss rate to the presence of various types of ice. This will be done during two field campaigns. During autumn, the boundary layer is less stratified and a gradient method will be used to quantify the deposition flux of dinitrogen pentoxide to the snowpack. During spring, the boundary layer is often very stratified, allowing sampling of air with little ground contact from a moderate-height tower (10 meters). Visibility measurements and microscopy will be used to quantify suspended ice particle surface area and size distributions. These comprehensive data sets will be used to address the question of what types of ice surfaces are primarily responsible for dinitrogen pentoxide losses during high-latitude nighttime. The important mechanisms will be implemented and tested in the Weather Research and Forecasting with Chemistry (WRF-Chem) model.Pollution in the Arctic is an increasing problem that may accelerate due to climate changes and industrial changes like trans-Arctic shipping and increased mineral exploration and extraction. By studying the fate of nitrogen oxide pollution under these conditions, this project will enhance the ability of planners, regulators, and industrial stakeholders to consider impacts of pollution on the Arctic. The research team is engaged with other researchers and with regulators studying particulate pollution in Fairbanks, which is now in violation of particulate matter standards, and will integrate the project's work with these particulate studies. Two students and a postdoctoral associate will be trained in atmospheric chemistry through this project, and the public will be engaged through blogging of field campaigns as they happen.