The Cryosphere Discussions www.the-cryosphere-discuss.net 1994-0432 1994-0440 4 1 2010 10.5194/tcd-4-153-2010 http://www.the-cryosphere-discuss.net/4/153/2010/ http://www.the-cryosphere-discuss.net/4/153/2010/tcd-4-153-2010.html http://www.the-cryosphere-discuss.net/4/153/2010/tcd-4-153-2010.pdf 153 161 2010-02-09 Brief communication: ikaite (CaCO₃*6H₂O) discovered in Arctic sea ice G. S. Dieckmann gerhard.dieckmann@awi.de G. Nehrke C. Uhlig J. Göttlicher S. Gerland M. A. Granskog D. N. Thomas Alfred-Wegener-Institute for Polar and Marine Research, Am Handelshafen 12, 27570 Bremerhaven, Germany Forschungszentrum Karlsruhe in der Helmholtz-Gemeinschaft, Institut für Synchrotronstrahlung, Hermann-von-Helmholtz-Platz 1, 76344 Eggenstein-Leopoldshafen, Germany Norsk Polarinstitutt, Polarmiljøsenteret, 9296 Tromsø, Norway School of Ocean Sciences, Bangor University, Menai Bridge, Anglesey, LL59 5AB, UK We report for the first time on the discovery of calcium carbonate crystals as ikaite (CaCO₃*6H₂O) in sea ice from the Arctic (Kongsfjorden, Svalbard). This finding demonstrates that the precipitation of calcium carbonate during the freezing of sea ice is not restricted to the Antarctic, where it was observed for the first time in 2008. This finding is an important step in the quest to quantify its impact on the sea ice driven carbon cycle and should in the future enable improvement parametrization sea ice carbon models. Aguilera, J., Bischof, K., Karsten, U., Hanelt, D., and Wiencke, C.: Seasonal variation in ecophysiological patterns in macroalgae from an Arctic fjord. II. Pigment accumulation and biochemical defence systems against high light stress, Mar. Biol., 140, 1087–1095, doi:10.1007/s00227-002-0792-y, 2002. Buchardt, B., Seaman, P., Stockmann, G., Vous, M., Wilken, U., Düwel, L., Kristiansen, A., Jenner, C., Whiticar, M. J., and Kristensen, R. M.: Submarine columns of ikaite tufa, Nature, 390, 129–130, doi:10.1038/36474, 1997 Dahl, K. and Buchardt, B.: Monohydrocalcite in the Arctic Ikka Fjord, SW Greenland: First reported marine occurrence, J. Sediment. Res., 76, 460–471, 2006. Dieckmann, G. S., Nehrke, G., Papadimitriou, S., Göttlicher, J., Steininger, R., Kennedy, H., Wolf-Gladrow, D., and Thomas, D. N.: Calcium carbonate as ikaite crystals in Antarctic sea ice, Geophys. Res. Lett., 35, L08501, doi:10.1029/2008GL033540, 2008. Gerland, S. and Renner, A. H. H.: Sea ice mass balance monitoring in an Arctic fjord, Ann. Glaciol., 46, 435–442, 2007. Jones, E. P. and Coote, A. R.: Oceanic CO₂ produced by the precipitation of CaCO₃ from brines in sea ice, J. Geophys. Res., 86, 11041–11043, 1981. Michel, F. M., MacDonald, J., Feng, J., Phillips, B. L., Ehm, L., Tarabrella, C., Parise, J. B., and Reeder, R. J.: Structural Characteristics of Synthetic Amorphous Calcium Carbonate, Chem. Mater., 20, 4720–4728, 2008. Omelon, C. R., Pollard. W. H., and Marion, G. M.: Seasonal formation of ikaite (CaCO₃*6H₂O) in saline spring discharge at Expedition Fiord, Canadian High Arctic: Assessing conditional constraints for natural crystal growth, Geochim. Cosmochim. Acta, 65, 1429–1437, 2001. Pauly, H.: "Ikaite" a new mineral from Greenland, Arctic, 16, 263–264, 1963. Rysgaard, S., Glud, R. N., Sejr, M. K., Bendtsen, J., and Christensen, P. B.: Inorganic carbon transport during sea ice growth and decay: A carbon pump in polar seas, J. Geophys. Res., 112, C03016, doi:10.1029/2006JC003572, 2007. Rysgaard, S., Bendtsen, J., Pedersen, L. T., Ramløv, H., and Glud,R. N.: Increased CO₂ uptake due to sea ice growth and decay in the Nordic Seas, J. Geophys. Res., 114, C09011, doi:10.1029/2008JC005088, 2009. Sander, R., Burrows, J., and Kaleschke, L.: Carbonate precipitation in brine – a potential trigger for tropospheric ozone depletion events, Atmos. Chem. Phys., 6, 4653–4658, 2006. Sander, R. and Morin, S.: Introducing the bromide/alkalinity ratio for a follow-up discussion on "Precipitation of salts in freezing seawater and ozone depletion events: a status report", by Morin et al., published in Atmos. Chem. Phys., 8, 7317–7324, 2008, Atmos. Chem. Phys. Discuss., 9, 20765–20773, 2009. Woelfel, J., Schumann, R., Leopold, P., Wiencke, C., and Karsten, U.: Microphytobenthic biomass along gradients of physical conditions in Arctic Kongsfjorden, Svalbard Bot. Mar., 52(6), 573–583, 2009.