Eastern Pacific Ocean circulation near the onset of the 1982–1983 El Niño

1986 ◽  
Vol 91 (C7) ◽  
pp. 8428 ◽  
Author(s):  
L. J. Mangum ◽  
S. P. Hayes ◽  
J. M. Toole
Atmosphere ◽  
2021 ◽  
Vol 12 (4) ◽  
pp. 424
Author(s):  
Yinlan Chen ◽  
Li Yan ◽  
Gen Li ◽  
Jianjun Xu ◽  
Jingchao Long ◽  
...  

In the recent four decades, there were three record-breaking El Niño events: 1982/1983, 1997/1998, and 2015/2016 events. A double intertropical convergence zone (ITCZ) pattern distinctively emerges over the eastern Pacific Ocean during boreal spring. Based on reanalysis (ERA-Interim) during 1979–2018, this study examines how these three extreme El Niños modulate such double ITCZs. The 1982/1983 and 1997/1998 El Niños moved both northern and southern ITCZs equatorward to form an individual and broad equatorial ITCZ. In contrast, the regulation of 2015/2016 El Niño was unique with a strengthened southern ITCZ to form a symmetric double-ITCZ. The above differences can be attributed to the different meridional structures of sea surface temperatures (SSTs). For the 1982/1983 and 1997/1998 El Niños, there was a meridionally symmetric structure of SST warming with a maximum at the equator. While for 2015/2016 El Niño, there was a meridionally symmetric structure of SST warming with a minimum at the equator.


2015 ◽  
Vol 66 (7) ◽  
pp. 644 ◽  
Author(s):  
Raul O. Martinez-Rincon ◽  
Sofia Ortega-Garcia ◽  
Juan G. Vaca-Rodriguez ◽  
Shane P. Griffiths

Sailfish (Istiophorus platypterus) is an important apex predator in neritic and oceanic pelagic ecosystems. The species is also a primary target of important catch-and-release sport fisheries that the support local economies of developing countries. However, commercial purse-seine fisheries that target tuna in the eastern Pacific Ocean (EPO) incidentally catch and discard large numbers of sailfish. Sailfish by-catch data recorded by scientific observers in the Mexican tuna purse-seine fleet in the EPO from 1998 to 2007 was used in generalised additive models (GAMs) to predict environmental and spatial preferences of sailfish. GAM predicted the highest sailfish catches to occur in coastal waters during El Niño events during late autumn and winter, with sea surface temperatures >26°C, with negative values of deviation in sea surface height (<–10cm), and low chlorophyll-a (<0.25mgm–3). GAM predicted that the catch probability for sailfish increased 1.8-fold during El Niño events in coastal waters and 1.5-fold under La Niña. However, the spatial distribution of sailfish remained largely unchanged during El Niño and La Niña events. Our models may be an additional fisheries management tool that may be used to support temporary spatial-temporal throughout the fishing season to reduce sailfish by-catch in the EPO.


Eos ◽  
2016 ◽  
Vol 97 ◽  
Author(s):  
Sarah Stanley

Underwater gliders and ocean modeling reveal unexpectedly weak El Niño effects on a major West Coast current.


2018 ◽  
Vol 586 ◽  
pp. 203-216 ◽  
Author(s):  
AR Gaos ◽  
RL Lewison ◽  
MP Jensen ◽  
MJ Liles ◽  
A Henriquez ◽  
...  

2021 ◽  
Author(s):  
Michael Mayer ◽  
Magdalena Alonso Balmaseda

AbstractThis study investigates the influence of the anomalously warm Indian Ocean state on the unprecedentedly weak Indonesian Throughflow (ITF) and the unexpected evolution of El Niño-Southern Oscillation (ENSO) during 2014–2016. It uses 25-month-long coupled twin forecast experiments with modified Indian Ocean initial conditions sampling observed decadal variations. An unperturbed experiment initialized in Feb 2014 forecasts moderately warm ENSO conditions in year 1 and year 2 and an anomalously weak ITF throughout, which acts to keep tropical Pacific ocean heat content (OHC) anomalously high. Changing only the Indian Ocean to cooler 1997 conditions substantially alters the 2-year forecast of Tropical Pacific conditions. Differences include (i) increased probability of strong El Niño in 2014 and La Niña in 2015, (ii) significantly increased ITF transports and (iii), as a consequence, stronger Pacific ocean heat divergence and thus a reduction of Pacific OHC over the two years. The Indian Ocean’s impact in year 1 is via the atmospheric bridge arising from altered Indian Ocean Dipole conditions. Effects of altered ITF and associated ocean heat divergence (oceanic tunnel) become apparent by year 2, including modified ENSO probabilities and Tropical Pacific OHC. A mirrored twin experiment starting from unperturbed 1997 conditions and several sensitivity experiments corroborate these findings. This work demonstrates the importance of the Indian Ocean’s decadal variations on ENSO and highlights the previously underappreciated role of the oceanic tunnel. Results also indicate that, given the physical links between year-to-year ENSO variations, 2-year-long forecasts can provide additional guidance for interpretation of forecasted year-1 ENSO probabilities.


2021 ◽  
Vol 241 ◽  
pp. 106001
Author(s):  
Osman Crespo-Neto ◽  
Eric Díaz-Delgado ◽  
Tatiana A. Acosta-Pachón ◽  
Raúl O. Martínez-Rincón

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