DOI: 10.25921/vprw-6e80
title: NOAA/WDS Paleoclimatology - Bering Sea, Chukchi Sea Diatom Abundances and Sea Ice Reconstructions 28 ka to present and 369-430 ka

description: Sea ice is an important component of Earth’s climate system, affecting it on both regional and global scales. Its incorporation into climate models is a necessary step to achieve more accurate predictions of future climate. However, instrumental records of sea ice concentration do not extend earlier than 1978. In an effort to extend this record, we constructed a proxy using the Generalized Additive Model based on relative abundances of five diatom species found in sediment samples across the Bering and Chukchi seas. Here we present the first quantitative diatom-based sea ice proxy developed for Beringia. The developed proxy has been applied to two sediment cores in the Bering Sea ranging from 0 to 25.7 ka and 369 to 430 ka and one in the Chukchi Sea ranging from 2.7 to 10 ka. The obtained reconstruction of sea ice concentration is similar, but not identical to previously published qualitative and nearby records. The proxy is publicly available as an R Shiny app and can be applied to any diatom count from marine sediments in the region.
description: Description: The age model for U1345 was previously published by Caissie et al. (2016). The age model for 24JPC was previously published by Pelto (2014). The age model for 51JPC is revised from Pelto et al. (2018) using the Marine20 calibration curve (Heaton et al., 2020) and the addition of an extra tephra correlation (T4, Misarti et al., 2012). The total reservoir correction is based on the calculation of reservoir ages from a nearby varved core (Kuehn et al., 2014). The new 51JPC age model is included in the 51JPC data file. Radiocarbon dates were collected on the benthic foraminifera Neogloboquadrina pachyderma. 
 Caissie, B.E., Brigham-Grette, J., Cook, M.S., Colmenero-Hidalgo, E., 2016. Bering Sea surface water conditions during Marine Isotope Stages 12 to 10 at Navarin Canyon (IODP Site U1345). Clim Past 12.
 Heaton, T.J., Köhler, P., Butzin, M., Bard, E., Reimer, R.W., Austin, W.E.N., Bronk Ramsey, C., Grootes, P.M., Hughen, K.A., Kromer, B., Reimer, P.J., Adkins, J., Burke, A., Cook, M.S., Olsen, J., Skinner, L.C., 2020. Marine20—The Marine Radiocarbon Age Calibration Curve (0–55,000 cal BP). Radiocarbon 62, 779-820.
 Kuehn, H., Lembke-Jene, L., Gersonde, R., Esper, O., Lamy, F., Arz, H., Kuhn, G., Tiedemann, R., 2014. Laminated sediments in the Bering Sea reveal atmospheric teleconnections to Greenland climate on millennial to decadal timescales during the last deglaciation. Clim Past 10, 2215-2236. 
 Misarti, N., Finney, B.P., Jordan, J.W., Maschner, H.D.G., Addison, J.A., Shapley, M.D., Krumhardt, A., Beget, J.E., 2012. Early retreat of the Alaska Peninsula Glacier Complex and the implications for coastal migrations of First Americans. Quaternary Science Reviews 48, 1-6.Pelto, B., 2014. Sedimentological, Geochemical and Isotopic Evidence for the Establishment of Modern Circulation through the Bering Strait and Depositional Environment History of the Bering and Chukchi Seas during the Last Deglaciation. University of Massachusetts Amherst. Pelto, B.M., Caissie, B.E., Petsch, S.T., Brigham-Grette, J., 2018. Oceanographic and Climatic Change in the Bering Sea, Last Glacial Maximum to Holocene. Paleoceanography and Paleoclimatology 33, 93-111.
        Provided Keywords: diatoms, quantitative proxy