Climate dependent contrast in surface mass balance in East Antarctica over the past 216 kyr
F. Parrenin1,2,*, S. Fujita3,4,*, A. Abe-Ouchi5,6, K. Kawamura3,4, V. Masson-Delmotte7, H. Motoyama3,4, F. Saito5, M. Severi8, B. Stenni9, R. Uemura10, and E. Wolff111CNRS, LGGE, 38041 Grenoble, France 2Univ. Grenoble Alpes, LGGE, 38041 Grenoble, France 3National Institute of Polar Research, Research Organization of Information and Systems, Tokyo, Japan 4Department of Polar Science, The Graduate University for Advanced Studies (SOKENDAI), Tokyo, Japan 5Japan Agency for Marine–Earth Science and Technology, Yokohama, Japan 6Atmosphere and Ocean Research Institute (AORI), University of Tokyo, Chiba, Japan 7Laboratoire des Sciences du Climat et de l'Environnement, Institut Pierre Simon Laplace, UMR CEA-CNRS-UVSQ 8212, Gif-sur-Yvette, France 8Department of Chemistry, University of Florence, Florence, Italy 9Department of Geosciences, University of Trieste, Trieste, Italy 10Department Chemistry, Biology and Marine Science, Faculty of Science, University of the Ryukyus, Okinawa, Japan 11Department of Earth Sciences, University of Cambridge, UK *These authors contributed equally to this work.
Received: 14 Jan 2015 – Accepted for review: 29 Jan 2015 – Discussion started: 17 Feb 2015
Abstract. Documenting past changes in the East Antarctic surface mass balance is important to improve ice core chronologies and to constrain the ice sheet contribution to global mean sea level. Here we reconstruct the past changes in the ratio of surface mass balance (SMB ratio) between the EPICA Dome C (EDC) and Dome Fuji (DF) East Antarctica ice core sites, based on a precise volcanic synchronisation of the two ice cores and on corrections for the vertical thinning of layers. During the past 216 000 years, this SMB ratio, denoted SMBEDC/SMBDF, varied between 0.7 and 1.1, decreasing during cold periods and increasing during warm periods. While past climatic changes have been depicted as homogeneous along the East Antarctic Plateau, our results reveal larger amplitudes of changes in SMB at EDC compared to DF, consistent with previous results showing larger amplitudes of changes in water stable isotopes and estimated surface temperature at EDC compared to DF. Within interglacial periods and during the last glacial inception (Marine Isotope Stages, MIS-5c and MIS-5d), the SMB ratio deviates by up to 30% from what is expected based on differences in water stable isotope records. Moreover, the SMB ratio is constant throughout the late parts of the current and last interglacial periods, despite contrasting isotopic trends. These SMB ratio changes not closely related to isotopic changes are one of the possible causes of the observed gaps between the ice core chronologies at DF and EDC. Such changes in SMB ratio may have been caused by (i) climatic processes related to changes in air mass trajectories and local climate, (ii) glaciological processes associated with relative elevation changes, or (iii) a combination of climatic and glaciological processes, such as the interaction between changes in accumulation and in the position of the domes. Our inferred SMB ratio history has important implications for ice sheet modeling (for which SMB is a boundary condition) or atmospheric modeling (our inferred SMB ratio could serve as a test).
Parrenin, F., Fujita, S., Abe-Ouchi, A., Kawamura, K., Masson-Delmotte, V., Motoyama, H., Saito, F., Severi, M., Stenni, B., Uemura, R., and Wolff, E.: Climate dependent contrast in surface mass balance in East Antarctica over the past 216 kyr, Clim. Past Discuss., 11, 377-405, doi:10.5194/cpd-11-377-2015, 2015.