Articles | Volume 17, issue 5
https://doi.org/10.5194/os-17-1385-2021
© Author(s) 2021. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
https://doi.org/10.5194/os-17-1385-2021
© Author(s) 2021. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
Interannual variability in contributions of the Equatorial Undercurrent (EUC) to Peruvian upwelling source water
Gandy Maria Rosales Quintana
CORRESPONDING AUTHOR
Department of Ocean Science, Tokyo University of Marine Science and Technology, Tokyo, Japan
Robert Marsh
School of Ocean and Earth Science, University of Southampton, Southampton, UK
Luis Alfredo Icochea Salas
Department of Fisheries Management and Environment, Universidad Nacional Agraria La Molina, Lima, Peru
Related authors
No articles found.
Melissa Wood, Ivan D. Haigh, Quan Quan Le, Hung Nghia Nguyen, Hoang Ba Tran, Stephen E. Darby, Robert Marsh, Nikolaos Skliris, and Joël J.-M. Hirschi
Nat. Hazards Earth Syst. Sci., 24, 3627–3649, https://doi.org/10.5194/nhess-24-3627-2024, https://doi.org/10.5194/nhess-24-3627-2024, 2024
Short summary
Short summary
We look at how compound flooding from the combination of river flooding and storm tides (storm surge and astronomical tide) may be changing over time due to climate change, with a case study of the Mekong River delta. We found that future compound flooding has the potential to flood the region more extensively and be longer lasting than compound floods today. This is useful to know because it means managers of deltas such as the Mekong can assess options for improving existing flood defences.
Matthew Clark, Robert Marsh, and James Harle
Ocean Sci., 18, 549–564, https://doi.org/10.5194/os-18-549-2022, https://doi.org/10.5194/os-18-549-2022, 2022
Short summary
Short summary
The European Slope Current (SC) is a northward-flowing current running parallel to the UK coastline. It is forced by changes in the density gradient of the wider North Atlantic Ocean. As the North Atlantic has warmed since the late 1990s, these gradients have changed strength and moved, reducing the volume and speed of water feeding into the SC. The SC flows into the North Sea, where changes in the species distribution of some plankton and fish have been seen due to the warming inputs.
Paul R. Halloran, Jennifer K. McWhorter, Beatriz Arellano Nava, Robert Marsh, and William Skirving
Geosci. Model Dev., 14, 6177–6195, https://doi.org/10.5194/gmd-14-6177-2021, https://doi.org/10.5194/gmd-14-6177-2021, 2021
Short summary
Short summary
This paper describes the latest version of a simple model for simulating coastal oceanography in response to changes in weather and climate. The latest revision of this model makes scientific improvements but focuses on improvements that allow the model to be run simply at large scales and for long periods of time to explore the implications of (for example) future climate change along large areas of coastline.
Emma L. Worthington, Ben I. Moat, David A. Smeed, Jennifer V. Mecking, Robert Marsh, and Gerard D. McCarthy
Ocean Sci., 17, 285–299, https://doi.org/10.5194/os-17-285-2021, https://doi.org/10.5194/os-17-285-2021, 2021
Short summary
Short summary
The RAPID array has observed the Atlantic meridional overturning circulation (AMOC) since 2004, but the AMOC was directly calculated only five times from 1957–2004. Here we create a statistical regression model from RAPID data, relating AMOC changes to density changes within the different water masses at 26° N, and apply it to historical hydrographic data. The resulting 1981–2016 record shows that the AMOC from 2008–2012 was its weakest since the mid-1980s, but it shows no overall decline.
Robert Marsh, Ivan D. Haigh, Stuart A. Cunningham, Mark E. Inall, Marie Porter, and Ben I. Moat
Ocean Sci., 13, 315–335, https://doi.org/10.5194/os-13-315-2017, https://doi.org/10.5194/os-13-315-2017, 2017
Short summary
Short summary
To the west of Britain and Ireland, a strong ocean current follows the steep slope that separates the deep Atlantic and the continental shelf. This “Slope Current” exerts an Atlantic influence on the North Sea and its ecosystems. Using a combination of computer modelling and archived data, we find that the Slope Current weakened over 1988–2007, reducing Atlantic influence on the North Sea, due to a combination of warming of the subpolar North Atlantic and weakening winds to the west of Scotland.
R. Marsh, A. E. Hickman, and J. Sharples
Geosci. Model Dev., 8, 3163–3178, https://doi.org/10.5194/gmd-8-3163-2015, https://doi.org/10.5194/gmd-8-3163-2015, 2015
Short summary
Short summary
Our relatively shallow shelf seas are warmed at the surface in spring and summer, while strong tidal currents act to mix away the surface warmth. These competing effects strongly influence the conditions for seasonal growth of the phytoplankton that support marine food webs. We have developed a versatile framework for fast computer modelling of shelf seas, to explore seasonal and year-to-year variations of warming and plankton productivity, tested against observations in different regions.
R. Marsh, V. O. Ivchenko, N. Skliris, S. Alderson, G. R. Bigg, G. Madec, A. T. Blaker, Y. Aksenov, B. Sinha, A. C. Coward, J. Le Sommer, N. Merino, and V. B. Zalesny
Geosci. Model Dev., 8, 1547–1562, https://doi.org/10.5194/gmd-8-1547-2015, https://doi.org/10.5194/gmd-8-1547-2015, 2015
Short summary
Short summary
Calved icebergs account for around 50% of total freshwater input to the ocean from the Greenland and Antarctic ice sheets. As they melt, icebergs interact with the ocean. We have developed and tested interactive icebergs in a state-of-the-art global ocean model, showing how sea ice, temperatures, and currents are disturbed by iceberg melting. With this new model capability, we are better prepared to predict how future increases in iceberg numbers might influence the oceans and climate.
Related subject area
Approach: Numerical Models | Properties and processes: “Modes of variability” e.g. ENSO | Depth range: Mixed Layer | Geographical range: Deep Seas: Equatorial Ocean | Challenges: Oceans and climate
A simple diagnostic based on sea surface height with an application to central Pacific ENSO
Jufen Lai, Richard J. Greatbatch, and Martin Claus
Ocean Sci., 19, 421–430, https://doi.org/10.5194/os-19-421-2023, https://doi.org/10.5194/os-19-421-2023, 2023
Short summary
Short summary
The El Niño Southern Oscillation (ENSO) has a global influence on weather and climate. Over most of the equatorial Pacific, where ENSO is focused, variations in sea surface height, such as measured by satellite, are strongly influenced by vertical displacements of the ocean thermocline. We show that linearly removing this influence leads to a time series of sea surface height that capture ENSO dynamics in the central Pacific, where ENSO variability has become more active in recent decades.
Cited articles
Ballón, M., Wosnitza-Mendo, C., Guevara-Carrasco, R., and Bertrand, A.: The impact of overfishing and El Niño on the condition factor and reproductive success of Peruvian hake, Merluccius gayi peruanus, Prog. Oceanogr., 79, 300–307, https://doi.org/10.1016/j.pocean.2008.10.016, 2008. a
Benites, C. and Barriga, E.: La Poblacion de la merluza durante el verano 2004, Crucero BIC Olaya 0401-02, Tech. rep., Instituto del Mar del Peru, Callao, ISSN 0378-7702, 2011. a
Blaker, A. T., Hirschi, J. J., McCarthy, G., Sinha, B., Taws, S., Marsh, R., Coward, A., and de Cuevas, B.: Historical analogues of the recent extreme minima observed in the Atlantic meridional overturning circulation at 26∘ N, Clim. Dynam., 44, 457–473, https://doi.org/10.1007/s00382-014-2274-6, 2015. a
Blanke, B. and Grima, N.: ARIANE software for tracking particles [code], available at: http://stockage.univ-brest.fr/~grima/Ariane/ariane.html (last access: 20 February 2021), 2018. a
Blanke, B. and Raynaud, S.: Kinematics of the Pacific Equatorial Undercurrent: An Eulerian and Lagrangian approach from GCM results, J. Phys. Oceanogr., 27, 1038–1053, https://doi.org/10.1175/1520-0485(1997)027<1038:KOTPEU>2.0.CO;2, 1997. a, b, c
Blanke, B., Arhan, M., Lazar, A., and Prévost, G.: A Lagrangian numerical investigation of the origins and fates of the salinity maximum water in the Atlantic, J. Geophys. Res.-Oceans, 107, 21–27, https://doi.org/10.1029/2002jc001318, 2002. a
Brown, J. N., Godfrey, J. S., and Fiedler, R.: A zonal momentum balance on density layers for the central and eastern equatorial Pacific, J. Phys. Oceanogr., 37, 1939–1955, https://doi.org/10.1175/JPO3090.1, 2007. a, b
Bryden, H. L. and Brady, E. C.: Diagnostic Model of the Three-Dimensional Circulation in the Upper Equatorial Pacific Ocean, J. Phys. Oceanogr., 15, 1255–1273, 1985. a
CALCOFI: California Cooperative Oceanic Fisheries Investigations, Tech. Rep. 5, National Oceanic and Atmospheric administration, National Marine Fisheries service, La Jolla CA, https://doi.org/10.1163/156851801511873, 2000.
a
Castillo, R.: Informe técnico sobre la situacióon de la merluza 1990–1995, Tech. rep., Instituto del Mar del Peru, Callao, available at:
https://hdl.handle.net/20.500.12958/899 (last access: 23 January 2021), 1996. a
Castillo, R., Ganoza, F., Aliaga, A., Gutiérrez, M., and
Guevara-Carrasco, R.: Distribución, concentración y biomasa de la merluza peruana en otoño 1997 con el método hidroacústico, Crucero BIC Humboldt 9705-06, Tech. rep., Instituto del Mar del Peru, Callao, available at:
https://hdl.handle.net/20.500.12958/1486 (last access: 23 January 2021), 1997. a, b
Castillo, R., Gomez, E., and Paredes, F.: Pesqueria y biologia de la Anguila
comun Ophichthus pacifici (Gunther)* en el Peru, Tech. rep., Instituto del Mar del Peru, Callao, available at:
https://hdl.handle.net/20.500.12958/1168 (last access: 20 February 2021), 2000. a
Chavez, F. P. and Messié, M.: A comparison of Eastern Boundary Upwelling Ecosystems, Prog. Oceanogr., 83, 80–96, https://doi.org/10.1016/j.pocean.2009.07.032, 2009. a, b, c
Chavez, F. P., Strutton, P. G., and McPhaden, M. J.: Biological-physical coupling in the central equatorial Pacific during the onset of the 1997–98 El Niño, Geophys. Res. Lett., 25, 3543–3546, https://doi.org/10.1029/98GL02729, 1998. a
Cheung W. L., W., Bruggeman, J., and Butenschön, M.: Chapter 4: Projected changes in global and national potential marine fisheries catch under climate change scenarios in the twenty-first century, in: Impacts of climate change on fisheries and aquaculture. Synthesis of current knowledge, adaptation and mitigation options, edited by: Barange, M., Bahri, T., Beveridge C. M., M., Cochrane L., K., Funge-Smith, S., and Poulain, F., vol. 627, chap. 4, Food and Agriculture Organization of the United Nations, Rome, 113–138, 2018. a
Chever, F., Rouxel, O. J., Croot, P. L., Ponzevera, E., Wuttig, K., and Auro, M.: Total dissolvable and dissolved iron isotopes in the water column of the Peru upwelling regime, Geochim. Cosmochim. Ac., 162, 66–82, https://doi.org/10.1016/j.gca.2015.04.031, 2015. a
Contreras Paya, I.: DOCUMENTO CONSOLIDADO, Convenio de desempeño 2016. Estatus y posibilidades de explotacion biologicamente sustentable de los principales recursos nacionales del 2017: Jibia, 2017, Tech. rep., Instituto de Fomento Pesquero, https://doi.org/10.13140/RG.2.2.20164.63365, 2017. a, b
Cromwell, T., Montgomery, R., and Stroup, E.: Equatorial Undercurrent in Pacific Ocean Revealed by New Methods, Science, 119, 648–649, https://doi.org/10.1126/science.119.3097.648, 1954. a, b
Donohue, K. A., Firing, E., Rowe, G. D., Ishida, A., and Mitsudera, H.: Equatorial pacific subsurface countercurrents: A model-data comparison in stream coordinates, J. Phys. Oceanogr., 32, 1252–1264, https://doi.org/10.1175/1520-0485(2002)032<1252:EPSCAM>2.0.CO;2, 2002. a, b
Doos, K.: Interocean exchange of water masses, J. Geophys. Res., 100, 499–514, 1995. a
Echevin, V., Gévaudan, M., Espinoza-Morriberón, D., Tam, J., Aumont, O., Gutierrez, D., and Colas, F.: Physical and biogeochemical impacts of RCP8.5 scenario in the Peru upwelling system, Biogeosciences, 17, 3317–3341, https://doi.org/10.5194/bg-17-3317-2020, 2020.
a
England, M. H., Mcgregor, S., Spence, P., Meehl, G. A., Timmermann, A., Cai, W., Gupta, A. S., Mcphaden, M. J., Purich, A., and Santoso, A.: Recent intensification of wind-driven circulation in the Pacific and the ongoing warming hiatus, Nat. Clim. Change, 4, 222–227, https://doi.org/10.1038/nclimate2106, 2014. a
Espinoza-Morriberón, D., Echevin, V., Colas, F., Tam, J., Gutierrez, D., Graco, M., Ledesma, J., and Quispe-Ccalluari, C.: Oxygen variability during ENSO in the Tropical South Eastern Pacific, Frontiers in Marine Science, 5, 1–20, https://doi.org/10.3389/fmars.2018.00526, 2019. a, b
Flores, R., Tenorio, J., and Dominguez, N.: Variaciones de la Extension Sur
de la Corriente Cromwell frente al Peru entre los 3 y 14∘ S,
Tech. rep., Instituto del Mar del Peru, Callao, available at:
https://hdl.handle.net/20.500.12958/1091 (last access: 22 January 2021), 2009. a
GTMBA Project Office of NOAA: Pacific Ocean – TAO [data set], available at: https://www.pmel.noaa.gov/gtmba/pmel-theme/pacific-ocean-tao (last access: 20 February 2021), 1982. a
Icochea, L., Chipollini, A., and Ñiquen, M.: Analisis de la pesqueria de arrastre pelagica en la costa peruana durante 1983–1987 y su relacion con el medio ambiente, in: Memorias del Simposio Internacional de los Recursos Vivos y las Pesquerias en el Pacifico Sudeste, Instituto del Mar del Peru,
Viña del Mar, 455–465, available at: https://www.researchgate.net/publication/304717388_Analisis_de_la_Pesqueria_de_Arrastre_pelagica_en_la_costa_peruana_durante_1983-1987_y_su_relacion_con_el_medio_ambiente (last access: 23 January 2021), 1989. a
Jakoboski, J., Todd, R. E., Brechner Owens, W., Karnauskas, K. B., and Rudnick, D. L.: Bifurcation and upwelling of the equatorial undercurrent west of the galápagos archipelago, J. Phys. Oceanogr., 50, 887–905, https://doi.org/10.1175/JPO-D-19-0110.1, 2020. a
Johnson, G. C. and Moore, D. W.: The pacific subsurface countercurrents and an inertial model, J. Phys. Oceanogr., 27, 2448–2459, https://doi.org/10.1175/1520-0485(1997)027<2448:TPSCAA>2.0.CO;2, 1997. a, b
Kämpf, J. and Chapman, P.: Upwelling Systems of the World. A Scientific Journey to the Most Productive Marine Ecosystems, Springer Nature, Switzerland, https://doi.org/10.1007/978-3-319-42524-5, 2016. a, b
Karnauskas, K. B., Murtugudde, R., and Busalacchi, A. J.: Observing the Galápagos-EUC interaction: Insights and challenges, J. Phys. Oceanogr., 40, 2768–2777, https://doi.org/10.1175/2010JPO4461.1, 2010. a, b, c
Karnauskas, K. B., Jakoboski, J., Johnston, T. M., Owens, W. B., Rudnick, D. L., and Todd, R. E.: The Pacific Equatorial Undercurrent in Three Generations of Global Climate Models and Glider Observations, J. Geophys. Res.-Oceans, 125, 1–12, https://doi.org/10.1029/2020JC016609, 2020. a
Kessler, S. and Mcphaden, J.: The 1991–1993 El Nifio in the central Pacific, Deep-Sea Res. Pt. II, 42, 295–333, https://doi.org/10.1016/0967-0645(95)00041-N, 1995. a
Kessler, W. S.: The circulation of the eastern tropical Pacific: A review, Prog. Oceanogr., 69, 181–217, https://doi.org/10.1016/j.pocean.2006.03.009, 2006. a
Kessler, W. S. and McPhaden, M. J.: The 1991–1993 El Niño in the central Pacific, Deep-Sea Res. Pt. II, 42, 295–333, https://doi.org/10.1016/0967-0645(95)00041-N, 1995. a
Knauss, J. A.: Observations of the Pacific Equatorial Undercurrent, Nature, 182, 601–602, https://doi.org/10.1038/182601a0, 1958. a
Knauss, J. A.: Measurements of the Cromwell current, Deep-Sea Res. (1953), 6, 265–286, https://doi.org/10.1016/0146-6313(59)90086-3, 1959. a, b, c, d
Kuntz, L. B. and Schrag, D. P.: Hemispheric asymmetry in the ventilated thermocline of the tropical pacific, J. Climate, 31, 1281–1288, https://doi.org/10.1175/JCLI-D-17-0686.1, 2018. a
Lassen, H., Barriga, E., Palacios, J., Vargas, N., Díaz, E., and
Argüelles, J.: Evaluación del estado del stock de merluza
(Merluccius gayi peruanus Ginsburg) en el mar peruano. 2008, Tech. Rep. 1-2,
Instituto del Mar del Peru, Callao, available at: https://hdl.handle.net/20.500.12958/1016 (last access: 15 January 2021), 2009. a, b
Madec, G.: NEMO ocean engine, Note du Pôle de modélisation, Institut Pierre-Simon Laplace (IPSL), France, No 27, 2008. a
Martina, J.: Analisis de la captura por unidad de esfuerzo (CPUE) de la
anguila comun (Ophichthus pacifici) y su relacion con la Corriente Cromwell,
PhD thesis, Universidad Nacional Agraria La Molina, available at: http://ban.lamolina.edu.pe/search~S1*spi?/cM11+M37+-+T/cm++++11+m37+t/-3%2C-1%2C0%2CB/frameset&FF=cm++++11+m37+t&1%2C1%2C (last access: 15 January 2021), 2004. a
Martina, J.: Estimación del coeficiente de capturabilidad (q) y de la biomasa de anguila común (Ophichthus remiger) del norte de Perú mediante análisis geoestadístico de las densidades de captura using likelihood-based geostatistical method on fish density, Anales Cientificos, 79, 168–177, https://doi.org/10.21704/ac.v79i1.1159, ISSN 2519-7398 (Versión electrónica), 2018. a
McPhaden, M. J.: Genesis and Evolution of the 1997–98 El Niño, Science, 283, 950–954, https://doi.org/10.1126/science.283.5404.950, 1999. a, b
Montes, I., Colas, F., Capet, X., and Schneider, W.: On the pathways of the equatorial subsurface currents in the eastern equatorial Pacific and their contributions to the Peru-Chile Undercurrent, J. Geophys. Res.-Oceans, 115, 1–16, https://doi.org/10.1029/2009JC005710, 2010. a, b, c
Ñiquen, M. and Bouchon, M.: Impact of El Niño events on pelagic fisheries in Peruvian waters, Deep-Sea Res. Pt. II, 51, 563–574, https://doi.org/10.1016/j.dsr2.2004.03.001, 2004. a, b
Pennington, J. T., Mahoney, K. L., Kuwahara, V. S., Kolber, D. D., Calienes, R., and Chavez, F. P.: Primary production in the eastern tropical Pacific: A review, Prog. Oceanogr., 69, 285–317, https://doi.org/10.1016/j.pocean.2006.03.012, 2006. a
Qin, X., Gupta, A. S., and van Sebille, E.: Variability in the origins and pathways of Pacific Equatorial Undercurrent, J. Geophys. Res.-Oceans, 120, 3113–3128, https://doi.org/10.1002/2014JC010549, 2015. a
Qin, X., Menviel, L., Sen Gupta, A., and van Sebille, E.: Iron sources and pathways into the Pacific Equatorial Undercurrent, Geophys. Res. Lett., 43, 9843–9851, https://doi.org/10.1002/2016GL070501, 2016. a, b, c
Ryan, J. P., Ueki, I., Chao, Y., Zhang, H., Polito, P. S., and Chavez, F. P.: Western Pacific modulation of large phytoplankton blooms in the central and eastern equatorial Pacific, J. Geophys. Res.-Biogeo., 111, 1–14, https://doi.org/10.1029/2005JG000084, 2006. a
Rykaczewski, R. R. and Checkley, D. M.: Influence of ocean winds on the pelagic ecosystem in upwelling regions, P. Natl. Acad. Sci. USA, 105, 1965–1970, https://doi.org/10.1073/pnas.0711777105, 2008. a, b
Shaffer, G., Pizarro, O., Djurfeldt, L., Salinas, S., and Rutllant, J.: Circulation and low-frequency variability near the Chilean coast: Remotely forced fluctuations during the 1991–92 El Niño, J. Phys. Oceanogr., 27, 217–235, https://doi.org/10.1175/1520-0485(1997)027<0217:CALFVN>2.0.CO;2, 1997. a
Slemons, L., Gorgues, T., Aumont, O., Menkes, C., and Murray, J. W.: Biogeochemical impact of a model western iron source in the Pacific Equatorial Undercurrent, Deep-Sea Res. Pt. I, 56, 2115–2128, https://doi.org/10.1016/j.dsr.2009.08.005, 2009. a
Tam, J., Purca, S., Duarte, L. O., Blaskovic, V., and Espinoza, P.: Changes in the diet of hake associated with El Niño 1997–1998 in the northern Humboldt Current ecosystem, Adv. Geosci., 6, 63–67, https://doi.org/10.5194/adgeo-6-63-2006, 2006. a
Tam, J., Taylor, M. H., Blaskovic, V., Espinoza, P., Michael Ballón, R., Díaz, E., Wosnitza-Mendo, C., Argüelles, J., Purca, S., Ayón, P., Quipuzcoa, L., Gutiérrez, D., Goya, E., Ochoa, N., and Wolff, M.: Trophic modeling of the Northern Humboldt Current Ecosystem, Part I: Comparing trophic linkages under La Niña and El Niño conditions, Prog. Oceanogr., 79, 352–365, https://doi.org/10.1016/j.pocean.2008.10.007, 2008. a
Taylor, M. H., Tam, J., Blaskovic, V., Espinoza, P., Michael Ballón, R., Wosnitza-Mendo, C., Argüelles, J., Díaz, E., Purca, S., Ochoa, N., Ayón, P., Goya, E., Gutiérrez, D., Quipuzcoa, L., and Wolff, M.: Trophic modeling of the Northern Humboldt Current Ecosystem, Part II: Elucidating ecosystem dynamics from 1995 to 2004 with a focus on the impact of ENSO, Prog. Oceanogr., 79, 366–378, https://doi.org/10.1016/j.pocean.2008.10.008, 2008. a
Terada, M., Minobe, S., and Deutsch, C.: Mechanisms of future changes in equatorial upwelling: CMIP5 intermodel analysis, J. Climate, 33, 497–510, https://doi.org/10.1175/JCLI-D-19-0128.1, 2020. a
Tsuchiya, M., Lukas, R., Fine, R. A., Firing, E., and Lindstrom, E.: Source waters of the Pacific Equatorial Undercurrent, Prog. Oceanogr., 23, 101–147, https://doi.org/10.1016/0079-6611(89)90012-8, 1989. a
Wang, Q., Wang, F., Feng, J., Hu, S., Zhang, L., Jia, F., and Hu, D.: The Equatorial Undercurrent and Its Origin in the Region Between Mindanao and New Guinea, J. Geophys. Res.-Oceans, 124, 2313–2330, https://doi.org/10.1029/2018JC014842, 2019. a
Wolf, A. E. and Tarazona, J.: Summary for Policymakers, in: Climate Change
2013 – The Physical Science Basis, edited by: Intergovernmental Panel on
Climate Change, vol. 52, Cambridge University Press, Cambridge,
https://doi.org/10.1017/CBO9781107415324.004, 1–30, 1989.
a
Wolff, M., Taylor, M., Mendo, J., and Yamashiro, C.: A catch forecast model for the Peruvian scallop (Argopecten purpuratus) based on estimators of spawning stock and settlement rate, Ecol. Model., 209, 333–341, https://doi.org/10.1016/j.ecolmodel.2007.07.013, 2007.
a
Yu, J. Y., Kao, H. Y., Lee, T., and Kim, S. T.: Subsurface ocean temperature indices for Central-Pacific and Eastern-Pacific types of El Niño and La Niña events, Theor. Appl. Climatol., 103, 337–344, https://doi.org/10.1007/s00704-010-0307-6, 2011. a
Short summary
The Equatorial Undercurrent (EUC) is a key influence on upwelling of nutrient-rich waters associated ecosystems off Peru. To quantify this influence, we backtrack upwelling waters in a computer model of ocean currents, annually, over 1989–2007. The EUC influence varies from year to year, dominating in warm El Niño years, when the EUC extends much closer to the Peruvian coast. In other years, more
localupwelling is associated with coastal winds, coincident with major key population shifts.
The Equatorial Undercurrent (EUC) is a key influence on upwelling of nutrient-rich waters...