USAP-DC

Hastings/1246223

This award supports a project with the aim of distinguishing the sources of nitrate deposition to the West Antarctic Ice Sheet (WAIS) using isotopic ratios snow in archive snow and ice samples. The isotopic composition of nitrate has been shown to contain information about the source of the nitrate (i.e. nitrogen oxides = NOx = NO+NO2) and the oxidation processes that convert NOx to nitrate in the atmosphere prior to deposition. A difficulty in interpreting records in the context of NOx sources is that nitrate can be post-depositionally processed in surface snow, such that the archived record does not reflect the composition of the atmosphere. This intellectual merit of this work specifically aims to investigate variability in the isotopic composition of nitrate in snow and ice from the WAIS in the context of accumulation rate, NOx source emissions, and atmospheric chemistry. These records will be interpreted in the context of our understanding of biospheric (biomass burning, microbial processes in soils), atmospheric (lightning, transport, chemistry), and climate (temperature, accumulation rate) changes over time. A graduate student will be supported as part of this project, and both graduate student and PI will be involved in communicating the utility and results of polar research to elementary school students in the Providence, RI area. The broader impacts of the project also include making efforts to attract more young, female scientists to polar research by establishing a connection between the Earth Science Women's Network (ESWN), an organization PI Hastings helped to establish, and the Association of Polar Early Career Scientists (APECS). Finally, results of all measurements will be presented at relevant conferences, made available publicly and published in peer-reviewed journals.

Person	Role
Hastings, Meredith	Investigator

Antarctic Glaciology

Award # 1246223

USAP-1246223

None in the Database

Repository	Title (link)	Format(s)	Status
USAP-DC	WAIS Divide WDC06A Nitrate Isotope Record	None	exist

1. Shi, G., *A. M. Buffen, M. G. Hastings, C. Li, H. Ma, Y. Li, B. Sun, C. An, and S. Jiang. "Investigation of post-depositional processing of nitrate in East Antarctic snow: isotopic constraints on photolytic loss, re-oxidation, and source inputs," Atmospheric Chemistry and Physics, v.15, 2015, p. 9435. (doi:10.5194/acp-15-9435-2015)
2. Shi, G., Buffen, A. M., Hastings, M. G., Li, C., Ma, H., Li, Y., … Jiang, S. (2014). Investigation of post-depositional processing of nitrate in East Antarctic snow: isotopic constraints on photolytic loss, re-oxidation, and source inputs. Atmospheric Chemistry and Physics Discussions, 14(23), 31943–31986. (doi:10.5194/acpd-14-31943-2014)
3. Shi, G., Buffen, A. M., Ma, H., Hu, Z., Sun, B., Li, C., … Hastings, M. G. (2018). Distinguishing summertime atmospheric production of nitrate across the East Antarctic Ice Sheet. Geochimica et Cosmochimica Acta, 231, 1–14. (doi:10.1016/j.gca.2018.03.025)
4. Shi, G., Chai, J., Zhu, Z., Hu, Z., Chen, Z., Yu, J., … Hastings, M. G. (2019). Isotope Fractionation of Nitrate During Volatilization in Snow: A Field Investigation in Antarctica. Geophysical Research Letters, 46(6), 3287–3297. (doi:10.1029/2019gl081968)
5. Shi, G., Buffen, A. M., Hu, Y., Chai, J., Li, Y., Wang, D., & Hastings, M. G. (2023). Modeling the Complete Nitrogen and Oxygen Isotopic Imprint of Nitrate Photolysis in Snow. Geophysical Research Letters, 50(12). Portico. (doi:10.1029/2023gl103778)