Effect of periodic melting on geochemical and isotopic signals in an ice core from Lomonosovfonna, SvalbardShow others and affiliations
Responsible organisation
2002 (English)In: Journal of Geophysical Research - Atmospheres, ISSN 2169-897X, E-ISSN 2169-8996, Vol. 107, no D4, article id 4036Article in journal (Refereed) Published
Abstract [en]
[1] We examine the quality of atmospherically deposited ion and isotope signals in an ice core taken from a periodically melting ice field, Lomonosovfonna in central Spitsbergen, Svalbard. The aim is to determine the degree to which the signals are altered by periodic melting of the ice. We use three diagnostics: (1) the relation between peak values in the ice chemical and isotopic record and ice facies type, (2) the number of apparent annual cycles in these records compared with independently determined number of years represented in the ice core, and (3) a statistical comparison of the isotopic record in the ice core and the isotope records from coastal stations from the same region. We find that during warm summers, as much as 50% of the annual accumulation may melt and percolate into the firn; in a median year this decreases to similar to25%. As a consequence of percolation, the most mobile acids show up to 50% higher concentrations in bubble-poor ice facies compared with facies that are less affected by melt. Most of the other chemical species are less affected than the strong acids, and the stable water isotopes show little evidence of mobility. Annual or biannual cycles are detected in most parameters, and the water isotope record has a comparable statistical distribution to isotopic records from coastal stations. We conclude that ice cores from sites like Lomonosovfonna contain a useful environmental record, despite melt events and percolation and that most parameters preserve an annual, or in the worst cases, a biannual atmospheric signal.
Place, publisher, year, edition, pages
Uppsala Univ, Dept Earth Sci, S-75236 Uppsala, Sweden. Univ Lapland, Arctic Ctr, FIN-96101 Rovaniemi, Finland. Norwegian Polar Res Inst, Polar Environm Ctr, N-9296 Tromso, Norway. Univ Utrecht, Inst Marine & Atmospher Res, NL-3508 TA Utrecht, Netherlands. Tallinn Univ Technol, Inst Geol, EE-10143 Tallinn, Estonia. Univ Groningen, Ctr Isotope Res, NL-9747 AG Groningen, Netherlands., 2002. Vol. 107, no D4, article id 4036
Keywords [en]
ice cores, snowmelt, water isotopes, ice chemistry, percolation in firn
Research subject
SWEDARCTIC
Identifiers
URN: urn:nbn:se:polar:diva-2441DOI: 10.1029/2000JD000149ISI: 000178891200006OAI: oai:DiVA.org:polar-2441DiVA, id: diva2:883484
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