Obliquity influence on low-latitude coastal precipitation in eastern Brazil during the past ∼850 kyr

• Verfasst von: Hou, Alicia [VerfasserIn]
• Verfasst von: Bahr, André [VerfasserIn]
• Verfasst von: Chiessi, Cristiano M. [VerfasserIn]
• Verfasst von: Jaeschke, Andrea [VerfasserIn]
• Verfasst von: Albuquerque, Ana Luiza S. [VerfasserIn]
• Verfasst von: Pross, Jörg [VerfasserIn]
• Verfasst von: Koutsodendris, Andreas [VerfasserIn]
• Verfasst von: Friedrich, Oliver [VerfasserIn]
• Titel: Obliquity influence on low-latitude coastal precipitation in eastern Brazil during the past ∼850 kyr
• Verf.angabe: Alicia Hou, André Bahr, Cristiano M. Chiessi, Andrea Jaeschke, Ana Luiza S. Albuquerque, Jörg Pross, Andreas Koutsodendris, and Oliver Friedrich
• E-Jahr: 2022
• Jahr: 01 February 2022
• Umfang: 15 S.
• Fussnoten: Im Titel wird die Tilde als Zeichen dargestellt ; Gesehen am 05.04.2022
• Titel Quelle: Enthalten in: Paleoceanography and paleoclimatology
• Ort Quelle: Hoboken, NJ : Wiley, 2018
• Jahr Quelle: 2022
• Band/Heft Quelle: 37(2022), 2, Artikel-ID e2021PA004238, Seite 1-15
• ISSN Quelle: 2572-4525
• DOI: doi:10.1029/2021PA004238
• Datenträger: Online-Ressource
• Sprache: eng
• Sach-SW: canopy temperature
• Sach-SW: diurnal vegetation dynamics
• Sach-SW: ecohydrologic dynamics
• Sach-SW: ECOSTRESS
• Sach-SW: semiarid mixed conifer forest
• Sach-SW: thermal UAS
• K10plus-PPN: 1797427016
• K10plus-PPN:
  Universitätsbibliothek
• Lokale URL UB: Zum Volltext

Abstract

Paleoclimate records from tropical South America typically show precession-paced variability in rainfall, caused by insolation-driven changes in the South American Monsoon System, however this mechanism may not be responsible for hydroclimate change outside of the core monsoon domain, such as in the coastal zone of tropical eastern Brazil. Our findings are based on a ∼850 kyr-long multiproxy record from a marine sediment core collected from the eastern Brazilian margin that represents the longest continuous record of South American hydroclimate to date. Utilizing the ln (K/Al) chemical weathering proxy from the core, we determine that past hydroclimate change in the coastal zone was primarily modulated by obliquity forcing. We demonstrate that high obliquity is associated with an increase in the boreal summer interhemispheric insolation contrast which decreases the zonality of the southern trade winds and reduces moisture advection to the coastal zone. Based on the long-term coherence between the ln (K/Al) record and benthic δ13C records from the Atlantic during Marine Isotope Stages 16-13, we infer that an increase in the strength of the overturning circulation, caused by Northern Hemisphere high-latitude forcing, may have produced surface cooling in the western tropical South Atlantic which led to reduced moisture advection to the coastal zone. We suggest that this mechanism may have also caused the amplification in millennial-scale variability in the coastal hydroclimate system, which began after the decoupling of the coastal hydroclimate system from obliquity forcing.