Status: this preprint has been withdrawn by the authors.
Imprint of Arctic sea ice cover in North-Greenland ice cores
Damiano Della Lunga,Hörhold Maria,Birthe Twarloh,Behrens Melanie,Dallmayr Remi,Erhardt Tobias,Jensen Camille Marie,and Wilhelms Frank
Abstract. Sea ice is a key component of the climate system, since it modifies the surface albedo, the radiation balance, as well as the exchange of heat, moisture and gases between the ocean and the overlying atmosphere. Hence, the reconstruction of sea ice cover before the instrumental era and the industrial times is crucial to understand the evolution of Arctic climate in the last millennium and better predict its future evolution. However, identifying relevant paleo proxies in climate archives related to sea ice cover is not straightforward. Ice cores from polar regions offer great potential to provide high-resolution records of Arctic sea ice variability from chemical impurities such as Bromine species, which were recently proposed as indicators of sea ice extent, although their variability might be modulated by regional influences. We here use Bromine and Bromine enrichment of two ice cores form North Greenland (B17 & B26) and investigate its potential as proxy to reconstruct sea ice extent over the period 1363–1993 AD. Across the instrumental period, a good correlation is observed with the Baffin Bay and the Greenland Sea for B26 and B17 respectively, with both record showing minima corresponding to known Artic warming events such as the 1420 AD (for B17) and 1920–1940 (Early century warming, B17 & B26), together with a strong decline starting in the late 19th century. We simultaneously derived a chemical classification of sea ice-related contributors of ionic species (i.e. blowing snow, frost flowers, open water) utilizing the depletion of SO42− compare to Ca2+, K+ and Mg2+ characterizing sea ice brines and blowing snow as well the excess of Br− and Cl−, characterizing frost flowers, to elucidate the evolution of the different sources. In both B17 and B26 records we observe a strong contribution of blowing snow in the earliest part of the datasets, gradually declining in recent years in favour of open water sources.
This preprint has been withdrawn.
How to cite. Della Lunga, D., Maria, H., Twarloh, B., Melanie, B., Remi, D., Tobias, E., Camille Marie, J., and Frank, W.: Imprint of Arctic sea ice cover in North-Greenland ice cores, The Cryosphere Discuss. [preprint], https://doi.org/10.5194/tc-2019-215, 2019.
Received: 11 Sep 2019 – Discussion started: 17 Oct 2019
The extent of sea ice plays a major role in the present Arctic warming, and it is possibly one of its first victims, since it has been predicted to disappear in the near future, if warming proceed. Our manuscript validates ice core proxies for the reconstruction of the variability of sea ice extent around Greenland in the last 600 years, and simultanesouly infers the evolution of the proxy-sources with time. Understanding past sea ice extent variability, is thus crucial in predicting its future.
The extent of sea ice plays a major role in the present Arctic warming, and it is possibly one...