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Abstract: We use new and published data to discuss the East Asian winter monsoon (EAWM) development and the relationship between the EAWM and the East Asian summer monsoon (EASM) since the Last Glacial Maximum (LGM) with special emphasis on the Holocene. The depth of the mixed layer in the northern South China Sea (SCS) is strongly modulated by the seasonal reversing monsoon winds with deeper vertical mixing during the winter monsoon season and less mixing during the summer monsoon season. Reconstructing the relative depth of the mixed layer thus represents a sensitive diagnostic variable of past changes in the EAWM strength. We derived estimates of the vertical thermal structure from the difference (∆T) in Mg/Ca-based temperatures between surface- (Globigerinoides ruber) and thermocline-dwelling (Pulleniatina obliquiloculata) planktonic foraminifera, and the temperature difference between alkenone and P. obliquiloculata in core MD05-2904 located in the northern SCS. Our ∆T estimates suggest enhanced upper water column mixing due to strengthened EAWM winds during the last glacial, consistent with other marine and terrestrial records as well as model simulations that also suggest a dominance of the cold and dry northwesterly winter monsoon system during the last glacial. Our ∆T estimates reveal that the EAWM was weaker during the Holocene compared to the last glacial. We find that EAWM and EASM changes show an inverse behaviour during the last glacial that is consistent with previous studies but co-varied during the Holocene. It can be inferred from these findings that the variability of the East Asian monsoon during the Holocene is more complex than the simple anti-phase relationship between summer and winter monsoon as assumed previously. The early-mid Holocene strengthening of both the EAWM and the EASM is most likely attributed to the higher summer insolation that resulted in a stronger seasonal contrast. [Copyright &y& Elsevier]

The integrated effects of the Western Pacific Warm Pool (WPWP) and the Kuroshio Current (KC) on the thermal evolution of the subtropical northwestern Pacific during the Holocene have remained elusive. This study presents new δ18O and Mg/Ca ratio records of subsurface-dwelling planktonic foraminifera Pulleniatina obliquiloculata at Site A7 in the Okinawa Trough to reconstruct thermocline-water evolution since the last deglaciation (∼18 ka) and further explore the effects of the WPWP and the KC dynamics throughout the Holocene. The Mg/Ca-based thermocline-water temperature (TWT) record displays a long-term cooling trend of ∼3 °C since the middle Holocene (∼7 ka), with a similar trend with that in the WPWP. Furthermore, two major thermocline warming events occurred with an amplitude of ∼2–3 °C in the early (∼11.8–9.5 ka) and middle (∼8–6.5 ka) Holocene, respectively. Both events are comparable with those in the WPWP. Besides, our TWT record had nine Holocene rapid cooling events with amplitudes of ∼1–2 °C around 1.7, 3.2, 4.4, 6.0, 7.2, 7.5, 8.2, 8.9, and 10 ka, respectively. The cooling events were also identified in the temperature records of the thermocline and/or intermediate waters in the WPWP within the chronological uncertainties. The comparability of these temperature records between both regions reveals that the dynamic KC transmitted thermal signals of the WPWP thermocline/intermediate waters into the Okinawa Trough on centennial to multi-millennial timescales, highlighting a crucial role of the WPWP in influencing subtropical ocean thermodynamics and climate in the Holocene. • Thermocline temperature record was reconstructed in the Okinawa Trough since 18 ka. • A mid- to late Holocene thermocline cooling trend and two major EH & MH thermocline warming events in the Okinawa Trough. • Thermal signals of the WPWP were transmitted by the KC on centennial to multi-millennial timescales in the Holocene. [ABSTRACT FROM AUTHOR]