Abstract: Micropaleontological and biomarker data from two high-accumulation marine sites from the Coastal and Continental Shelf Zone (CCSZ) off East Antarctica (Adélie Land at w140°E and eastern Prydz Bay at w77°E) are used to reconstruct Holocene changes in sea ice and wind stress at the basin-wide scale. These data demonstrate congruent increase in sea-ice concentration/persistence and wind stress-related sea-surface turbulence in the two regions since 7 cal ka BP, with a particularly strong signal since 4.5 - 3.5 cal ka BP. Comparison of these high latitude records with sea ice and turbulence records from the southern mid-latitudes highlights distinctive climatic evolutions according to the different latitudinal bands. Sea-ice persistence and turbulence increase in East Antarctica CCSZ are opposite to sea-surface warming and sea-ice retreat recorded after 4.5 - 3.5 cal ka BP in the East Atlantic and Indian sector between 55 and 45°S. At the same period, paleodata suggest SST cooling in all major coastal upwelling systems of the southern hemisphere, caused by the northward transport of subpolar surface waters as a response to southern Westerlies reinforcement. We therefore propose, as suggested for the northern hemisphere, that Holocene changes in the latitudinal insolation gradient, primarily forced by obliquity and precession and amplified by sea-ice and glacial-ice expansions in the Antarctic realm, are responsible for the observed contrasted latitudinal patterns of southern latitudes.
Source: Supplement to: Denis, Delphine; Crosta, Xavier; Barbara, Loïc; Massé, Guillaume; Renssen, Hans; Ther, Olivier; Giraudeau, Jacques (2010): Sea ice and wind variability during the Holocene in East Antarctica: insight on middleehigh latitude coupling. Quaternary Science Reviews, 29, 3709-3719, https://doi.org/10.1016/j.quascirev.2010.08.007
Supplemental Information: Age is given in calendar years BP.
Data were obtained within the framework of the ERC StG ICEPROXY project (Grant number: 203441) and ANR CLIMICE (ANR-08-CEXC-012-01), provided for the data compilation of the Past4Future Project. Core MD03-2601 was retrieved during Images X cruise with the logistic support of IPEV-TAAF.
Coverage: EVENT LABEL: MD03-2601 (MD032601) * LATITUDE: -66.051200 * LONGITUDE: 138.557200 * DATE/TIME: 2003-02-08T08:51:00 * ELEVATION: -746.0 m * Recovery: 40.3 m * LOCATION: Southern Ocean * CAMPAIGN: MD130 * BASIS: Marion Dufresne (1995) * METHOD/DEVICE: Calypso Corer