Evidence for Holocene centennial variability in sea ice cover based on IP25 biomarker reconstruction in the southern Kara Sea (Arctic Ocean)

• Published in: Geo-Marine Letters
• Main Authors: Hörner, Tanja, Stein, Rüdiger, Fahl, Kirsten
• Format: Article in Journal/Newspaper
• Language: unknown
• Published: 2017
• Subjects: Arctic; Arctic Ocean; Kara Sea; North Atlantic; North Atlantic oscillation; Sea ice
• Online Access: https://epic.awi.de/id/eprint/45490/; https://doi.org/10.1007/s00367-017-0501-y; https://hdl.handle.net/10013/epic.51608

The Holocene is characterized by the late Holocene cooling trend as well as by internal short-term centennial fluctuations. Because Arctic sea ice acts as a significant component (amplifier) within the climate system, investigating its past long- and short-term variability and controlling processes is beneficial for future climate predictions. This study presents the first biomarker-based (IP25 and PIP25) sea ice reconstruction from the Kara Sea (core BP00-07/7), covering the last 8 ka. These biomarker proxies reflect conspicuous short-term sea ice variability during the last 6.5 ka that is identified unprecedentedly in the source region of Arctic sea ice by means of a direct sea ice indicator. Prominent peaks of extensive sea ice cover occurred at ~3, ~2, ~1.3 and ~0.3 ka. Spectral analysis of the IP25 record revealed ~400- and ~950-year cycles. These periodicities may be related to the Arctic/North Atlantic Oscillation, but probably also to internal climate system fluctuations. This demonstrates that sea ice belongs to a complex system that more likely depends on multiple internal forcing.