Millennial‐Scale Precipitation Variability in the Indo‐Pacific Region Over the Last 40 Kyr

Abstract

Abstract Deep atmospheric convection in the Indo‐Pacific Warm Pool (IPWP) represents a major source of heat and moisture, thereby affecting the global climate, but its past changes remain debated. Here, we present sub‐millennial clay mineralogy and elemental records spanning the last 40 Kyr from within the IPWP. From these data, we infer millennial‐scale fluctuations in precipitation, with generally lower precipitation during Heinrich Stadials 1–4, corresponding to El Niño‐like conditions. Higher precipitation coincided with the warm interstadials, accompanied by La Niña‐like conditions. Moreover, our record indicates the lowest precipitation occurred during the late Holocene, supporting the hypothesis of a stronger‐than‐modern Walker circulation during the Last Glacial Maximum. In combination with other proxy records and TraCE‐21 modeling results, we recognize a distinct spatial heterogeneity of precipitation within the IPWP, resulting from the dominant influences of the ENSO‐like system and migration of the Intertropical Convergence Zone in the eastern and western IPWP, respectively.

Keywords

• weathering
• clay mineralogy
• hydroclimate
• ENSO
• Indo‐Pacific Warm Pool