Aridification of northwest Australia and nutrient decline in the Timor Sea during the 40 kyr world

Abstract Studying tropical hydroclimate and productivity change in the past is critical for understanding global climate dynamics. Northwest Australia an ideal location investigating Australian monsoon dynamics, variability of Indonesian Throughflow (ITF), their impact on Pacific warm pool evolution, which remain poorly understood during 40 kyr world mid‐early Pleistocene. In this study, we present multi‐proxy records from International Ocean Discovery Program (IODP) Site U1483 Timor Sea spanning last 2000 ka, including orbitally‐resolved between 1300 ka. Our results suggest that northwest underwent a step increased aridification declined transition ∼ 1700 to 1400 We attribute reduced moisture supply region caused by ITF restriction contraction. ascribe decrease nutrient source water associated with redistribution. At orbital timescale, multiple mechanisms, sea level changes, monsoon, Intertropical Convergence Zone (ITCZ) variations Walker circulation could have controlled terrigenous input world. bulk nitrogen benthic carbon isotope strong coupling biogeochemical changes period. This research contributes better