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Response of O2 and pH to ENSO in the California Current System in a high-resolution global climate model

Abstract.

"Coastal upwelling systems, such as the California Current System (CalCS), naturally experience a wide range of O2 concentrations and pH values due to the seasonality of upwelling. Nonetheless, changes in the El Niño–Southern Oscillation (ENSO) have been shown to measurably affect the biogeochemical and physical properties of coastal upwelling regions. In this study, we use a novel, high-resolution global climate model (GFDL-ESM2.6) to investigate the influence of warm and cold ENSO events on variations in the O2 concentration and the pH of the CalCS coastal waters. [...]"

Source: Ocean Science
Authors:  Giuliana Turi et al.
DOI: 10.5194/os-14-69-2018

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Climate and anthropogenic controls of coastal deoxygenation on interannual to centennial timescales

Abstract.

"Understanding dissolved oxygen variability in the ocean is limited by the short duration of direct measurements, however sedimentary oxidation-reduction reactions can provide context for modern observations. Here we use bulk sediment redox-sensitive metal enrichment factors (MoEF, ReEF, and UEF) and scanning X-ray fluorescence (XRF) records to examine annual-scale sedimentary oxygen concentrations in the Santa Barbara Basin from the Industrial Revolution (AD ~1850) to present. [...]"

Source: Geophysical Research Letters
Authors: Yi Wang, Ingrid Hendy, Tiffany J. Napier
DOI: 10.1002/2017GL075443

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Impacts of El Niño events on the Peruvian upwelling system productivity

Abstract.

"Every 2–7 years, El Niño events trigger a strong decrease in phytoplankton productivity off Peru, which profoundly alters the environmental landscape and trophic chain of the marine ecosystem. Here we use a regional coupled physical-biogeochemical model to study the dynamical processes involved in the productivity changes during El Nino, with a focus on the strongest events of the 1958–2008 period. Model evaluation using satellite and in situ observations shows that the model reproduces the surface and subsurface interannual physical and biogeochemical variability. [...]"

Source: Journal of Geophysical Research: Oceans
Authors: D. Espinoza-Morriberón
DOI: 10.1002/2016JC012439

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Influence of seaway changes during the Pliocene on tropical Pacific climate in the Kiel climate model

 Mean state, annual cycle, ENSO, and their interactions

Abstract.

"The El Niño/Southern Oscillation (ENSO) is the leading mode of tropical Pacific interannual variability in the present-day climate. Available proxy evidence suggests that ENSO also existed during past climates, for example during the Pliocene extending from about 5.3 million to about 2.6 million years BP. Here we investigate the influences of the Panama Seaway closing and Indonesian Passages narrowing, and also of atmospheric carbon dioxide (CO2) on the tropical Pacific mean climate and annual cycle, and their combined impact on ENSO during the Pliocene. [...]"

Source: Climate Dynamics
Authors: Zhaoyang Song, Mojib Latif, Wonsun Park, Uta Krebs-Kanzow, Birgit Schneider
DOI: 10.1007/s00382-016-3298-x

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Impacts of ENSO on air-sea oxygen exchange: observations and mechanisms

Abstract.

"Models and observations of Atmospheric Potential Oxygen (APO ≃ O2 + 1.1*CO2) are used to investigate the influence of El Niño Southern Oscillation (ENSO) on air-sea O2 exchange. An atmospheric transport inversion of APO data from the Scripps flask network shows significant interannual variability in tropical APO fluxes that is positively correlated with the Niño3.4 index, indicating anomalous ocean outgassing of APO during El Niño. Hindcast simulations of the Community Earth System Model (CESM) and the Institut Pierre-Simon Laplace (IPSL) model show similar APO sensitivity to ENSO, differing from the Geophysical Fluid Dynamic Laboratory (GFDL) model, which shows an opposite APO response. [...]"

Source: Global Biochemical Cycles
Authors: Yassir A. Eddebbar et al.
DOI: 10.1002/2017GB005630

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