DOI 10.1016/j.quascirev.2022.107756 The Solomon Sea is the main source of the equatorial undercurrent and the main crossroad of the equatorial region and the South Pacific Ocean. Based on multi-species planktonic foraminiferal geochemical proxies, here we reconstruct the vertical thermal-hydrological variabilities over the last 568,000 years in the Solomon Sea. The proxies used include the differences between δ18O data of the surface dweller Globigerinoides ruber (white) and the subsurface dweller Pulleniatina obliquiloculata (Δδ18Oc), the sea surface temperature (SST) and the upper thermocline temperature (UTT) as well as their differences (ΔT), and the seawater oxygen isotope differences (Δδ18Ow). Both the SST and UTT records feature similar timing of warming, which is 2–4 kyr earlier than the G/IG boundaries for the past six terminations. Different from the other five terminations, both SST and UTT records of Termination V show a persistent and early increase of 5–7 °C in 10 kyr since ∼440 ka. On the obliquity band, higher SST and UTT correspond to larger obliquity, suggesting higher subtropical South Pacific input. This argument is supported by lower ΔT and higher Δδ18Ow. In the meantime, higher SST and UTT also correspond to precession minimum, suggesting an expansion of the mixed layer with lower ΔT and greater Δδ18Ow. Our results show complex interactions between precipitation-evaporation and water masses exchange in the Solomon Sea. The clear obliquity signal observed in multiple proxies reveals strong interactions between the Solomon Sea and the mid-high latitude South Pacific regions.
Thermocline structure, Orbital forcing, Western pacific warm pool, Terminations
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Publisher's official version | 16 | 6 Mo | ||
Supplementary figure 1. (a) MD05-2925 composite benthic foraminifera with different species; oxygen isotope stratigraphy with global stack LR04 (Lisiecki and Raymo, 2005). Filtering results of ... | 1 | 949 Ko | ||
Supplementary figure 2. Records of MD05-2925 (a) surface and (b) subsurface planktonic foraminiferal Mg/Ca ratios, (c) averaged single G. ruber shell weight over the past 568 ka. Inferred (d) G. ... | 1 | 1 Mo | ||
Supplementary figure 3. Comparison between ice-volume corrected seawater d18O (δ18Ow-ivc) records of (a) surface and (b) subsurface with different sea level correction models (Spratt et al., 2016; ... | 1 | 1 Mo | ||
Supplementary figure 4. Comparison of (a) SST and (b) seawater d18O (δ18Ow) records between MD05-2925 (red) and MD97-2120 (green, Pahnke et al., 2003). Gray bars are glacial periods. Marine isotope... | 1 | 661 Ko | ||
Supplementary figure 5. Ensemble Empirical Mode Decomposition (EEMD, Huang et al., 1998) results of DT. Composites of (a) imf 5–9 (a) and (b) imf 1–4 of MD05-2925 DT. Single spectrum results of (c) .. | 1 | 535 Ko | ||
Supplementary figure 6. Phase wheel plots from the results of cross-spectral analyses between surface, subsurface, and differences of calcite d18O (δ18Oc), temperature, and ice-volume corrected ... | 1 | 317 Ko | ||
Author's final draft | 52 | 3 Mo |
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