First Ice Core Records of NO3- Stable Isotopes from Lomonosovfonna, Svalbard
2015 (English)In: Journal of Geophysical Research - Atmospheres, ISSN 2169-897X, E-ISSN 2169-8996, Vol. 120, no 1, 313-330 p.Article in journal (Refereed) Published
Samples from two ice cores drilled at Lomonosovfonna, Svalbard, covering the period 1957-2009, and 1650-1995, respectively, were analyzed for NO(3)(-)concentrations, and NO3- stable isotopes (N-15 and O-18). Post-1950 N-15 has an average of (-6.91.9), which is lower than the isotopic signal known for Summit, Greenland but agrees with values observed in recent Svalbard snow and aerosol. Pre-1900 N-15 has an average of (4.21.6)parts per thousand suggesting that natural sources, enriched in the N-15 isotope, dominated before industrialization. The post-1950 O-18 average of (75.1 +/- 4.1)parts per thousand agrees with data from low and polar latitudes, suggesting similar atmospheric NOy (NOy=NO+NO2+HNO3) processing pathways. The combination of anthropogenic source N-15 and transport isotope effect was estimated as -29.1 parts per thousand for the last 60years. This value is below the usual range of NOx (NOx=NO+NO2) anthropogenic sources which is likely the result of a transport isotope effect of -32 parts per thousand. We suggest that the N-15 recorded at Lomonosovfonna is influenced mainly by fossil fuel combustion, soil emissions, and forest fires; the first and second being responsible for the marked decrease in N-15 observed in the post-1950s record with soil emissions being associated to the decreasing trend in N-15 observed up to present time, and the third being responsible for the sharp increase of N-15 around 2000.
Place, publisher, year, edition, pages
2015. Vol. 120, no 1, 313-330 p.
Earth and Related Environmental Sciences
Research subject Earth Science with specialization in Physical Geography
IdentifiersURN: urn:nbn:se:uu:diva-221776DOI: 10.1002/2013JD020930ISI: 000349104700020OAI: oai:DiVA.org:uu-221776DiVA: diva2:709969