scholarly journals Mechanisms of the intensification of the upwelling-favorable winds during El Niño 1997–1998 in the Peruvian upwelling system

2018 ◽  
Vol 51 (9-10) ◽  
pp. 3717-3733 ◽  
Author(s):  
Adolfo Chamorro ◽  
Vincent Echevin ◽  
François Colas ◽  
Vera Oerder ◽  
Jorge Tam ◽  
...  
Keyword(s):  
El Niño ◽  
El Nino ◽  
Upwelling System

scholarly journals Regional-scale changes in diatom distribution in the Humboldt upwelling system as revealed by remote sensing: implications for fisheries

2010 ◽  
Vol 68 (4) ◽  
pp. 729-736 ◽  
Author(s):  
Thomas Jackson ◽  
Heather A. Bouman ◽  
Shubha Sathyendranath ◽  
Emmanuel Devred
Keyword(s):  
Remote Sensing ◽  
El Niño ◽  
El Nino ◽  
Regional Scale ◽  
Detection Algorithm ◽  
Larval Survival ◽  
Upwelling System ◽  
Diatom Population ◽  
Engraulis Ringens ◽  
Zooplankton Communities

Abstract Jackson, T., Bouman, H. A., Sathyendranath, S., and Devred, E. 2011. Regional-scale changes in diatom distribution in the Humboldt upwelling system as revealed by remote sensing: implications for fisheries. – ICES Journal of Marine Science, 68: 729–736. A diatom-detection algorithm was parametrized for the Humboldt upwelling system using local cruise data that were first validated, then used to create monthly composites of diatom distribution from 0 to 40°S and 90 to 70°W for both normal and El Niño conditions. There was a 50% reduction in the areal extent of diatom-dominated waters during the peak of the 1997 El Niño. The extent of the coastward contraction in the diatom-dominated area varied along the South American coastline. These regional shifts in phyto- and zooplankton communities would have increased food stress on local anchovy (Engraulis ringens) populations and could have contributed to diminished larval survival and landings the following year. A region of strong upwelling over the wide Peruvian continental shelf around 15°S was the only area that maintained a strong diatom population throughout the El Niño; the area may require special protection from fishing pressure in years following an El Niño event.

Inorganic carbon in the central California upwelling system during the 1997–1999 El Niño–La Niña event

2002 ◽  
Vol 54 (1-4) ◽  
pp. 185-203 ◽  
Author(s):  
G.E Friederich ◽  
P.M Walz ◽  
M.G Burczynski ◽  
F.P Chavez
Keyword(s):  
El Niño ◽  
Inorganic Carbon ◽  
El Nino ◽  
La Niña ◽  
Central California ◽  
Upwelling System ◽  
La Nina ◽  
La Nina Event

scholarly journals Inter-annual variability of the Pelagic-Benthic coupling in the upwelling system off central Chile

2006 ◽  
Vol 6 ◽  
pp. 127-132 ◽  
Author(s):  
M. Graco ◽  
D. Gutiérrez ◽  
L. Farías
Keyword(s):  
El Niño ◽  
El Nino ◽  
Southern Oscillation ◽  
Coastal Region ◽  
Euphotic Zone ◽  
Carbon Fluxes ◽  
Water Interface ◽  
Central Chile ◽  
Upwelling System ◽  
Benthic Coupling

Abstract. The coastal region of central Chile (36° S) is one of the most productive coastal systems, characterized by a marked seasonality in the upwelling regime, that brings subsurface waters rich in nutrient and poor in oxygen (ESSW) into the euphotic zone. This oceanographic condition depends basically on the equatorward wind strength and is modified on different time scales, with the El Niño-Southern Oscillation (ENSO) phenomenon as the main source of interannual variability in the Pacific Ocean. Here we present an effort to integrate physical and biogeochemical variability associated with in situ information and experiments at coastal stations off central Chile (36° S) in order to improve the knowledge on the pelagic-benthic coupling in this upwelling system during the warm ENSO phase or El Niño. Carbon fluxes exported from the water column to the sediments and the ammonium exchange across the sediment-water interface are discussed together with oceanographic and benthic conditions. All measurements and estimations were carried out from May 1997 until April 2001 at two stations, one located inside Concepción Bay (~28 m depth), and the other on the continental shelf at ~36° S (~88 m depth). The results show that the pelagic and benthic systems are strongly coupled off central Chile (36° S). Oceanographic variability associated with upwelling events (seasonal scale) and an El Niño event (interannual scale) was observed. The carbon fluxes exported to the sediments, the benthic conditions (i.e., quantity and quality of the sediment organic matter), and the ammonium exchange across the sediment-water interface, responded to the seasonal regime of upwelling during non El Niño years as well as to the ENSO related oceanographic variability.

Biological and chemical consequences of the 1997–1998 El Niño in the Chilean coastal upwelling system: a synthesis

2004 ◽  
Vol 51 (20-21) ◽  
pp. 2389-2411 ◽  
Author(s):  
Rubén Escribano ◽  
Giovani Daneri ◽  
Laura Farías ◽  
Víctor A. Gallardo ◽  
Humberto E. González ◽  
...  
Keyword(s):  
El Niño ◽  
Coastal Upwelling ◽  
El Nino ◽  
Upwelling System ◽  
System A

scholarly journals The OMZ and nutrient features as a signature of interannual and low-frequency variability in the Peruvian upwelling system

2017 ◽  
Vol 14 (20) ◽  
pp. 4601-4617 ◽  
Author(s):  
Michelle I. Graco ◽  
Sara Purca ◽  
Boris Dewitte ◽  
Carmen G. Castro ◽  
Octavio Morón ◽  
...  
Keyword(s):  
El Niño ◽  
El Nino ◽  
Kelvin Wave ◽  
Central Pacific ◽  
Data Set ◽  
Central Pacific El Niño ◽  
Humboldt Current ◽  
Upwelling System ◽  
Anammox Activity ◽  
Weak Regime

Abstract. Over the last decades, the Humboldt Current upwelling ecosystem, particularly the northern component off the coast of Peru, has drawn the interest of the scientific community because of its unique characteristics: it is the upwelling system with the biggest catch productivity despite the fact it is embedded in a shallow and intense oxygen minimum zone (OMZ). It is also an area of intense nitrogen loss and anammox activity and experiences large interannual variability associated with the equatorial remote forcing. In this context, we examined the oceanographic and biogeochemical variability associated with the OMZ off central Peru from a monthly time series (1996–2011) recorded off the coast of Callao (12° 02′ S, 77° 29′ W). The data reveal a rich spectrum of variability in the OMZ that includes frequencies ranging from seasonal to interannual scales. Due to the efficient oceanic teleconnection off Peru, the observed variability is interpreted in the light of an estimate of the equatorial Kelvin wave contribution to sea level anomalies considering the peculiarities of its vertical structure (i.e., the first two baroclinic modes). The span of the data set allows us to contrast two OMZ regimes. The strong regime is associated with the strong 1997–1998 equatorial Pacific El Niño, during which the OMZ adjusted to Kelvin-wave-induced downwelling conditions that switched off the upwelling and drastically reduced nutrient availability. The weak regime corresponds to the post-2000 period associated with the occurrence of moderate central Pacific El Niño events and enhanced equatorial Kelvin wave activity, in which mean upwelling conditions are maintained. It is shown that the characteristics of the coupling between physics and biogeochemistry is distinct between the two regimes with the weak regime being associated with a larger explained variance in biogeochemical properties not linearly related to the ENSO oceanic teleconnection. The data also reveal a long-term trend from 1999 corresponding to a deepening of the oxygen-deficient waters and warming. The implications of our results for understanding the OMZ dynamics off Peru are discussed.

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