Peeken Ilka

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Last Name
Peeken
First Name
Ilka
ORCID
0000-0003-1531-1664

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  • Article
    Neodymium isotopes trace marine provenance of Arctic sea ice
    (European Association of Geochemistry, 2022-06-10) Laukert, Georgi ; Peeken, Ilka ; Bauch, Dorothea ; Krumpen, Thomas ; Hathorne, Ed C. ; Werner, Kirstin ; Gutjahr, Marcus ; Frank, Martin
    Radiogenic neodymium (Nd) isotopes (ɛNd) have the potential to serve as a geochemical tracer of the marine origin of Arctic sea ice. This capability results from pronounced ɛNd differences between the distinct marine and riverine sources, which feed the surface waters from which the ice forms. The first dissolved Nd isotope and rare earth element (REE) concentration data obtained from Arctic sea ice collected across the Fram Strait during RV Polarstern cruise PS85 in 2014 confirm the incorporation and preservation of the parental surface seawater ɛNd signatures despite efficient REE rejection. The large ɛNd variability between ice floes and within sea ice cores (−32 to −10) reflects changes in water mass distribution during ice growth and drift from the central Arctic Ocean to Fram Strait. In addition to the parental seawater composition, our new approach facilitates the reconstruction of the transfer of matter between the atmosphere, the sea ice and the ocean. In conjunction with satellite-derived drift trajectories, we enable a more accurate assessment of sea ice origin and spatiotemporal evolution, benefiting studies of sea ice biology, biodiversity, and biogeochemistry.
  • Article
    The seeding of ice algal blooms in Arctic pack ice : the multiyear ice seed repository hypothesis
    (John Wiley & Sons, 2017-07-03) Olsen, Lasse M. ; Laney, Samuel R. ; Duarte, Pedro ; Kauko, Hanna Maria ; Fernández-Méndez, Mar ; Mundy, Christopher J. ; Rösel, Anja ; Meyer, Amelie ; Itkin, Polona ; Cohen, Lana ; Peeken, Ilka ; Tatarek, Agnieszka ; Róźańska-Pluta, Magdalena ; Wiktor, Jozef ; Taskjelle, Torbjørn ; Pavlov, Alexey K. ; Hudson, Stephen R. ; Granskog, Mats A. ; Hop, Haakon ; Assmy, Philipp
    During the Norwegian young sea ICE expedition (N-ICE2015) from January to June 2015 the pack ice in the Arctic Ocean north of Svalbard was studied during four drifts between 83° and 80°N. This pack ice consisted of a mix of second year, first year, and young ice. The physical properties and ice algal community composition was investigated in the three different ice types during the winter-spring-summer transition. Our results indicate that algae remaining in sea ice that survived the summer melt season are subsequently trapped in the upper layers of the ice column during winter and may function as an algal seed repository. Once the connectivity in the entire ice column is established, as a result of temperature-driven increase in ice porosity during spring, algae in the upper parts of the ice are able to migrate toward the bottom and initiate the ice algal spring bloom. Furthermore, this algal repository might seed the bloom in younger ice formed in adjacent leads. This mechanism was studied in detail for the dominant ice diatom Nitzschia frigida. The proposed seeding mechanism may be compromised due to the disappearance of older ice in the anticipated regime shift toward a seasonally ice-free Arctic Ocean.