FN Archimer Export Format PT J TI Holocene long- and short-term climate changes off Adelie Land, East Antarctica BT AF CROSTA, X. DEBRET, M. DENIS, D. COURTY, M. A. THER, O. AS 1:1;2:2;3:1;4:3;5:1; FF 1:;2:;3:;4:;5:; C1 UMR-CNRS 5805 EPOC, Talence, France Laboratoire de Glaciologie et de Geophysique de l'Environnement, St Martin d'Heres, France UMR 5198, CNRS-IPH, Tautavel, France C2 EPOC, FRANCE LGGE, FRANCE CNRS, FRANCE IF 2.354 TC 48 UR https://archimer.ifremer.fr/doc/00235/34642/33044.pdf LA English DT Article CR MD 130 / CADO BO Marion Dufresne DE ;Antarctica;sea ice;Holocene;insolation;thermohaline circulation AB Diatom data from a marine sediment core give insight on Holocene changes in sea- surface conditions and climate at high southern latitudes off Adelie Land, East Antarctica. The early to mid- Holocene was warmer than the late Holocene with a transition at similar to 4000 calendar years B. P. Sea ice was less present and spring- summer growing season was greater during the warm period relative to the cold one, thus limiting sea ice diatom production and favoring more open ocean diatom to develop. The long- term Holocene climatic evolution in East Antarctica is explained by a combination of a delayed response to local seasonal insolation changes coupled to the long memory of the Southern Ocean. Abrupt variations of the diatom relative abundances, indicating rapid climate changes, are superimposed to the Holocene long- term trends. Spectral analyses calculate robust frequencies at similar to 1600 a ( where "a'' is years), similar to 1250 a, similar to 1050 a, similar to 570 a, similar to 310 a, similar to 230 a, similar to 150 - 125 a, similar to 110 a, similar to 90 a, and similar to 66 a. Such periods are very close to solar activity cyclicities, except for the periods at similar to 310 a and similar to 1250 a, which are close to internal climate variability cyclicities. Wavelet analyses estimate the same periods but indicate nonstationary cyclicities. Rapid climate changes at high southern latitudes may therefore be explained by a combination of external ( solar) and internal ( thermohaline circulation) forcings. PY 2007 PD NOV SO Geochemistry Geophysics Geosystems SN 1525-2027 PU Amer Geophysical Union VL 8 IS 11 UT 000251344500002 BP 1 EP 15 DI 10.1029/2007GC001718 ID 34642 ER EF