FN Archimer Export Format PT J TI Assessing divergent SST behavior during the last 21 ka derived from alkenones and G. ruber-Mg/Ca in the equatorial Pacific BT AF TIMMERMANN, Axel SACHS, Julian TIMM, Oliver Elison AS 1:1;2:2;3:3; FF 1:;2:;3:; C1 Univ Hawaii Manoa, Int Pacific Res Ctr, SOEST, Honolulu, HI 96822 USA. Univ Washington, Sch Oceanog, Seattle, WA 98195 USA. SUNY Albany, Dept Atmospher & Environm Sci, Albany, NY 12222 USA. C2 UNIV HAWAII MANOA, USA UNIV WASHINGTON, USA SUNY ALBANY, USA IF 3.738 TC 49 UR https://archimer.ifremer.fr/doc/00290/40134/39215.pdf LA English DT Article CR IMAGES 3-IPHIS-MD106 IMAGES 4-MD111 MD 122 / WEPAMA MD 126 / MONA MD 148 / PECTEN BO Marion Dufresne AB Equatorial Pacific SST reconstructions derived from Mg/Ca ratios in planktonic foraminifera Globigerinoides ruber and from alkenone-producing coccolithophorids record different trends throughout the Holocene and the last deglaciation. We set forth the hypothesis that their diverging behavior may be related to different seasonal sensitivities which result from the annually varying production rates of alkenone-producing coccolithophorids and of G. ruber. Using a series of transient paleoclimate model simulations forced with the time-varying forcing history over the last 21 ka, a good qualitative agreement is found between simulated boreal winter temperatures and alkenone-SST reconstructions as well as between simulated boreal summer temperatures and reconstructed Mg/Ca-based SST variations. Pronounced features in the reconstructions that can be readily explained by the conjectured seasonal biases include the mismatch in middle-to-late Holocene temperature trends and the different onsets of deglacial climate change in the eastern equatorial Pacific. The analysis presented here further suggests that through combinations of Mg/Ca and alkenone SST reconstructions information can be gained on annual mean temperature changes and the amplitude of the seasonal cycle in SST. Our study concludes by discussing potential weaknesses of the proposed model-derived seasonal bias interpretation of tropical Pacific SST proxies in terms of present-day core-top data, sediment trap studies, and satellite-based observations of chlorophyll. PY 2014 PD JUL SO Paleoceanography SN 0883-8305 PU Amer Geophysical Union VL 29 IS 6 UT 000340661100014 BP 680 EP 696 DI 10.1002/2013PA002598 ID 40134 ER EF