FN Archimer Export Format PT J TI Half-precessional cycle of thermocline temperature in the western equatorial Pacific and its bihemispheric dynamics BT AF Jian, Zhimin Wang, Yue Dang, Haowen Lea, David W. Liu, Zhengyu Jin, Haiyan Yin, Yaqian AS 1:1;2:1;3:1;4:2;5:3;6:1;7:1; FF 1:;2:;3:;4:;5:;6:;7:; C1 State Key Laboratory of Marine Geology, Tongji University, 200092 Shanghai, China Department of Earth Science, University of California, Santa Barbara, CA 93106, USA Department of Geography, Ohio State University, Columbus, OH 43210, USA C2 UNIV TONGJI, CHINA UNIV CALIF SANTA BARBARA, USA UNIV OHIO STATE, USA IF 11.205 TC 34 UR https://archimer.ifremer.fr/doc/00614/72647/71649.pdf https://archimer.ifremer.fr/doc/00614/72647/71650.pdf LA English DT Article CR MD 122 / WEPAMA BO Marion Dufresne DE ;thermocline temperature;half-precession;western equatorial Pacific;meridional gradient AB The El Niño−Southern Oscillation (ENSO), which is tightly coupled to the equatorial thermocline in the Pacific, is the dominant source of interannual climate variability, but its long-term evolution in response to climate change remains highly uncertain. This study uses Mg/Ca in planktonic foraminiferal shells to reconstruct sea surface and thermocline water temperatures (SST and TWT) for the past 142 ky in a western equatorial Pacific (WEP) core MD01-2386. Unlike the dominant 100-ky glacial−interglacial cycle recorded by SST and δ18O, which echoes the pattern seen in other WEP sites, the upper ocean thermal gradient shows a clear half-precessional (9.4 ky or 12.7 ky) cycle as indicated by the reconstructed and simulated temperature (ΔT) and δ18O differences between the surface and thermocline waters. This phenomenon is attributed to the interplay of subtropical-to-tropical thermocline anomalies forced by the antiphased meridional insolation gradients in the two hemispheres at the precessional band. In particular, the TWT shows greater variability than SST, and dominates the ΔT changes which couple with the west−east SST difference in the equatorial Pacific at the half-precessional band, implying a decisive role of the tropical thermocline in orbital-scale climate change. PY 2020 PD MAR SO Proceedings Of The National Academy Of Sciences Of The United States Of America SN 0027-8424 PU Proceedings of the National Academy of Sciences VL 117 IS 13 UT 000523188100020 BP 7044 EP 7051 DI 10.1073/pnas.1915510117 ID 72647 ER EF