Publication Date
10-1-2023
Document Type
Article
Publication Title
Paleoceanography and Paleoclimatology
Volume
38
Issue
10
DOI
10.1029/2023PA004683
Abstract
Studying tropical hydroclimate and productivity change in the past is critical for understanding global climate dynamics. Northwest Australia is an ideal location for investigating Australian monsoon dynamics, the variability of the Indonesian Throughflow (ITF), and their impact on past productivity and Pacific warm pool evolution, which remain poorly understood during the 40 kyr world in the mid-early Pleistocene. In this study, we present multi-proxy records from International Ocean Discovery Program (IODP) Site U1483 in the Timor Sea spanning the last 2,000 ka, including orbitally-resolved records from the 40 kyr world between 2,000 and 1,300 ka. Our results suggest that northwest Australia underwent a step of increased aridification and that productivity in the Timor Sea declined during the transition from ∼1,700 to ∼1,400 ka. We attribute this aridification to the reduced moisture supply to this region caused by the ITF restriction and warm pool contraction. We ascribe the declined productivity to a decrease in the nutrient supply of the Pacific source water associated with global nutrient redistribution. At orbital timescale, multiple mechanisms, including sea level changes, monsoon, and the Intertropical Convergence Zone (ITCZ) dynamics, and variations in the ITF and Walker circulation could have controlled variations of productivity and terrigenous input in the Timor Sea during the 40 kyr world. Our bulk nitrogen and benthic carbon isotope records suggest a strong coupling to biogeochemical changes in the Pacific during this period. This research contributes to a better understanding of tropical hydroclimate and productivity changes during the 40 kyr world.
Funding Number
1736686
Funding Sponsor
National Science Foundation
Keywords
Australian monsoon, mid-early Pleistocene (40 kyr world), northwest Australia (the Timor Sea), the Indonesian throughflow (ITF), tropical hydroclimate, tropical productivity
Creative Commons License
This work is licensed under a Creative Commons Attribution-Noncommercial 4.0 License
Department
Moss Landing Marine Laboratories
Recommended Citation
Y. Zhang, T. Andrade, A. C. Ravelo, L. Gong, A. Holbourn, G. Connock, X. L. Liu, and I. W. Aiello. "Aridification of Northwest Australia and Nutrient Decline in the Timor Sea During the 40 Kyr World" Paleoceanography and Paleoclimatology (2023). https://doi.org/10.1029/2023PA004683
