Seasonal accumulation timing and preservation of nitrate in firn at Summit, Greenland

Burkhart, John F.; Hutterli, Manuel; Bales, Roger C.; McConnell, Joseph R. (2004). Seasonal accumulation timing and preservation of nitrate in firn at Summit, Greenland. Journal of Geophysical Research: Atmospheres, 109(D19), pp. 1-9. American Geophysical Union 10.1029/2004JD004658

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In a yearlong investigation of the air-snow transfer function for nitrate (NO3−) at the Greenland Environmental Observatory, Summit (3203 m above sea level), surface snow concentrations measured every other day were compared with levels measured in 10 snow pits dug adjacent to accumulation stakes. Concentrations in the surface snow ranged from 0.4 to 34 μM with a mean of 2.9 ± 1.9 μM. Measured firn profiles in the snow pits had a maximum NO3− concentration of 12 μM and a mean of 2.7 ± 0.5 μM. Reconstructed profiles from surface snow observations and accumulation data closely matched the observed profiles. The small difference in preserved concentrations from observed surface snow concentrations gives evidence of only 7% postdepositional loss at this site (mean annual accumulation ∼23 g cm−2 yr−1). Removing the three highest outliers (which may originate from local sources) of surface snow concentration drops the mean to 2.7 μM, further demonstrating preservation. Results indicate that at this site accumulation is the most significant process affecting preservation of nitrate in the firn. Other rapid postdepositional processes may impact surface snow concentrations, but do not appear to significantly change the preserved record. The inverse analysis of converting preserved records to surface snow concentrations provides equivalent evidence of the same preservation.

Item Type:

Journal Article (Original Article)

Division/Institute:

08 Faculty of Science > Physics Institute > Climate and Environmental Physics

UniBE Contributor:

Hutterli, Manuel

Subjects:

500 Science > 530 Physics

ISSN:

2169-897X

Publisher:

American Geophysical Union

Language:

English

Submitter:

BORIS Import 2

Date Deposited:

19 Aug 2021 16:07

Last Modified:

05 Dec 2022 15:52

Publisher DOI:

10.1029/2004JD004658

BORIS DOI:

10.48350/158303

URI:

https://boris.unibe.ch/id/eprint/158303

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