Pervasive multidecadal variations in productivity within the Peruvian Upwelling System over the last millennium
| Autor: | Isabelle Billy, Xavier Crosta, Sophie Fleury, Karine Charlier, Thomas Blanz, Vincent Hanquiez, Philippe Martinez, Ralph R Schneider |
|---|---|
| Přispěvatelé: | Environnements et Paléoenvironnements OCéaniques (EPOC), Observatoire aquitain des sciences de l'univers (OASU), Université Sciences et Technologies - Bordeaux 1-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Sciences et Technologies - Bordeaux 1-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-École pratique des hautes études (EPHE), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS), Institut für Geowissenschaften [Kiel], Christian-Albrechts-Universität zu Kiel (CAU) |
| Rok vydání: | 2015 |
| Předmět: |
[SDU.OCEAN]Sciences of the Universe [physics]/Ocean
Atmosphere Archeology Global and Planetary Change Intertropical Convergence Zone Geology 15. Life on land Oxygen minimum zone Productivity (ecology) [SDU.STU.CL]Sciences of the Universe [physics]/Earth Sciences/Climatology 13. Climate action North Atlantic oscillation Climatology Walker circulation Upwelling 14. Life underwater Precipitation Climate state [SDU.STU.OC]Sciences of the Universe [physics]/Earth Sciences/Oceanography Ecology Evolution Behavior and Systematics |
| Zdroj: | Quaternary Science Reviews Quaternary Science Reviews, Elsevier, 2015, 125, pp.78-90. ⟨10.1016/j.quascirev.2015.08.006⟩ |
| ISSN: | 0277-3791 |
| Popis: | There is no agreement on the pluri-decadal expression of El Nino-Southern Oscillation (ENSO) in the Pacific over the last millennium. Marine records from the Peruvian margin indicate humid conditions (El Nino-like mean conditions) over the Little Ice Age, while precipitation records from the eastern equatorial Pacific infer arid conditions (La Nina-like mean conditions) for the same period. We here studied diatom assemblages, nitrogen isotopes, and major and minor elements at the lamination level in three laminated trigger cores located between 11 degrees S and 15 degrees S on the Peruvian shelf within the oxygen minimum zone (OMZ) to reconstruct precipitation and ocean productivity at the multiannual to multidecadal timescales over the last millennium. We respected the sediment structure, thus providing the first records of the mean climatic conditions at the origin of the lamination deposition, which ones represent several years. Light laminations were deposited under productive and dry conditions, indicative of La Nina-like mean conditions in the system, while dark laminations were deposited under non-productive and humid conditions, representative of El Nino-like mean conditions. La Nina-like mean conditions were predominant during the Medieval Warm Period (MWP; 1000-600 years BP) and Current Warm Period (CWP; 150 years BP to present), while El Nino-like mean conditions prevailed over the Little Ice Age (LIA; 600-150 years BP). We provide evidence for persistent multidecadal variations in productivity over the last millennium, which were disconnected from the mean climate state. Multidecadal variability has been stronger over the last 450 years concomitantly to increased variability in the NAO index. Two intervals of strong multidecadal variability were also observed over the MWP, congruent to decreased solar irradiance and increased volcanic activity. (C) 2015 Elsevier Ltd. All rights reserved. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|
Full Text from ScienceDirect