Project: Photochemistry at “Dirty” Ice Surfaces: Effects of Solutes on Reactivity
Investigator: Tara Kahan
Sponsor: National Science Foundation/Faculty Early Career Development (CAREER) Award
Amount Awarded: $579,340 (September 2015-August 2020)
Background: As the Arctic warms and new shipping routes become available, human activity in the Arctic will increase. Energy extraction and use, transportation, and catastrophic events, such as oil spills, will increase pollutant loadings in the Arctic. Pollutants associated with energy extraction and use can react with sunlight (“photolyze”) to form more toxic products that are harmful to aquatic organisms, including coral reefs and invertebrates, as well as aquatic and terrestrial mammals ranging from seals to humans.
It is therefore necessary to understand what factors control pollutant reactivity in the Arctic (i.e., how fast they react and what products they form) in order to accurately predict the effects of increased human activity on air and water quality and to develop evidence-based policy to protect fragile ecosystems.
While pollutant reactivity has been extensively studied in liquid water (relevant to rivers, lakes, and oceans), large fractions of the Arctic (both land and water) are frozen for at least several months of the year. Therefore, pollutant reactivity in ice must be understood in order to quantify the health effects of pollutants associated with fossil fuels in the Arctic.
Impact: The data generated by this research will greatly improve models that predict pollutant fate in the environment. This work will also provide a molecular-level view of ice surfaces, showing for the first time how pollutants interact with solutes, such as sea salt, at ice surfaces, and how these solutes affect pollutant reactivity.
The impacts of this work extend beyond the Arctic. Many cities experience snow cover for a fraction of the year; pollutant photolysis in snow and ice may have significant effects on human health due to the high concentrations of both pollutants and people. This chemistry may also be very important in regions used for energy extraction; extremely high levels of pollutants have been detected near hydraulic fracturing (“fracking”) operations. This research will help to inform policy to protect the environment and human health in snow-covered locations across the globe.
The project includes an educational component: local middle-school children will attend a week-long summer workshop on science reporting. They will learn about environmental issues facing Syracuse and will interview an environmental scientist. These interviews will be displayed for the public as videos, posters, and blogs as a temporary exhibit at the Milton J. Rubenstein Museum of Science and Technology in downtown Syracuse.
A map of a frozen salt-water surface: The brighter blue areas indicate saltwater and the dark blue indicates pure ice. The map shows that ice surfaces have complex structures.