Precession modulation of the South Pacific westerly wind belt over the past million years ...

• Main Authors: Lamy, Frank, Chiang, John C H, Martínez Méndez, Gema, Thierens, Mieke, Arz, Helge Wolfgang, Bosmans, Joyce H C, Hebbeln, Dierk, Lambert, Fabrice, Lembke-Jene, Lester, Stuut, Jan-Berend W
• Format: Article in Journal/Newspaper
• Language: English
• Published: PANGAEA 2019
• Subjects: Paleoenvironmental Reconstructions from Marine Sediments @ AWI AWI_Paleo; Antarc*; Antarctic; Ice Sheet; Southern Ocean
• Online Access: https://dx.doi.org/10.1594/pangaea.907631; https://doi.pangaea.de/10.1594/PANGAEA.907631

The southern westerly wind belt (SWW) interacts with the Antarctic Circumpolar Current and strongly impacts the Southern Ocean carbon budget, and Antarctic ice-sheet dynamics across glacial- interglacial cycles. We investigated precipitation-driven sediment input changes to the Southeast Pacific off the southern margin of the Atacama Desert in Chile over the past one million years, revealing strong precession (19/23-ka) cycles. Our simulations with 2 ocean-atmosphere general circulation models suggest that observed cyclic rainfall changes are linked to meridional shifts in water vapor transport from the tropical Pacific toward the southern Atacama Desert. These changes reflect a precessional modulation of the split in the austral winter South Pacific jet stream. For precession maxima, we infer significantly enhanced rainfall in the southern Atacama Desert due to a stronger South Pacific split jet with enhanced subtropical/subpolar jets, and a weakermidlatitude jet. Conversely, we derive dry conditions in ... : Supplement to: Lamy, Frank; Chiang, John C H; Martínez Méndez, Gema; Thierens, Mieke; Arz, Helge Wolfgang; Bosmans, Joyce H C; Hebbeln, Dierk; Lambert, Fabrice; Lembke-Jene, Lester; Stuut, Jan-Berend W (2019): Precession modulation of the South Pacific westerly wind belt over the past million years. Proceedings of the National Academy of Sciences of the United States of America ...