The equatorial current system west of the Galapagos Islands during the 2014-16 El Niño as observed by underwater gliders
Rudnick, Daniel L.
Owens, W. Brechner
Johnston, T. M. Shaun
Karnauskas, Kristopher B.
Jakoboski, Julie K.
Todd, Robert E.
MetadataShow full item record
The strong El Niño of 2014–16 was observed west of the Galápagos Islands through sustained deployment of underwater gliders. Three years of observations began in October 2013 and ended in October 2016, with observations at longitudes 93° and 95°W between latitudes 2°N and 2°S. In total, there were over 3000 glider-days of data, covering over 50 000 km with over 12 000 profiles. Coverage was superior closer to the Galápagos on 93°W, where gliders were equipped with sensors to measure velocity as well as temperature, salinity, and pressure. The repeated glider transects are analyzed to produce highly resolved mean sections and maps of observed variables as functions of time, latitude, and depth. The mean sections reveal the structure of the Equatorial Undercurrent (EUC), the South Equatorial Current, and the equatorial front. The mean fields are used to calculate potential vorticity Q and Richardson number Ri. Gradients in the mean are strong enough to make the sign of Q opposite to that of planetary vorticity and to have Ri near unity, suggestive of mixing. Temporal variability is dominated by the 2014–16 El Niño, with the arrival of depressed isopycnals documented in 2014 and 2015. Increases in eastward velocity advect anomalously salty water and are uncorrelated with warm temperatures and deep isopycnals. Thus, vertical advection is important to changes in heat, and horizontal advection is relevant to changes in salt. Implications of this work include possibilities for future research, model assessment and improvement, and sustained observations across the equatorial Pacific.
Author Posting. © American Meteorological Society, 2021. This article is posted here by permission of American Meteorological Society for personal use, not for redistribution. The definitive version was published in Journal of Physical Oceanography 51(1),(2021): 3-17, https://doi.org/10.1175/JPO-D-20-0064.1.
Suggested CitationRudnick, D. L., Owens, W. B., Johnston, T. M. S., Karnauskas, K. B., Jakoboski, J., & Todd, R. E. (2021). The equatorial current system west of the Galapagos Islands during the 2014-16 El Niño as observed by underwater gliders. Journal of Physical Oceanography, 51(1), 3-17.
Showing items related by title, author, creator and subject.
Todd, Robert E.; Chavez, Francisco P.; Clayton, Sophie A.; Cravatte, Sophie; Goes, Marlos Pereira; Graco, Michelle; Lin, Xiaopei; Sprintall, Janet; Zilberman, Nathalie; Archer, Matthew; Arístegui, Javier; Balmaseda, Magdalena A.; Bane, John M.; Baringer, Molly O.; Barth, John A.; Beal, Lisa M.; Brandt, Peter; Calil, Paulo H. R.; Campos, Edmo; Centurioni, Luca R.; Chidichimo, Maria Paz; Cirano, Mauro; Cronin, Meghan F.; Curchitser, Enrique N.; Davis, Russ E.; Dengler, Marcus; deYoung, Brad; Dong, Shenfu; Escribano, Ruben; Fassbender, Andrea; Fawcett, Sarah E.; Feng, Ming; Goni, Gustavo J.; Gray, Alison R.; Gutiérrez, Dimitri; Hebert, Dave; Hummels, Rebecca; Ito, Shin-ichi; Krug, Marjolaine; Lacan, Francois; Laurindo, Lucas; Lazar, Alban; Lee, Craig M.; Lengaigne, Matthieu; Levine, Naomi M.; Middleton, John; Montes, Ivonne; Muglia, Mike; Nagai, Takeyoshi; Palevsky, Hilary I.; Palter, Jaime B.; Phillips, Helen E.; Piola, Alberto R.; Plueddemann, Albert J.; Qiu, Bo; Rodrigues, Regina; Roughan, Moninya; Rudnick, Daniel L.; Rykaczewski, Ryan R.; Saraceno, Martin; Seim, Harvey E.; Sen Gupta, Alexander; Shannon, Lynne; Sloyan, Bernadette M.; Sutton, Adrienne J.; Thompson, LuAnne; van der Plas, Anja K.; Volkov, Denis L.; Wilkin, John L.; Zhang, Dongxiao; Zhang, Linlin (Frontiers Media, 2019-08-08)Ocean boundary current systems are key components of the climate system, are home to highly productive ecosystems, and have numerous societal impacts. Establishment of a global network of boundary current observing systems ...
Hausmann, Ute; McGillicuddy, Dennis J.; Marshall, John (John Wiley & Sons, 2017-01-27)Combining satellite altimetry with Argo profile data a systematic observational estimate of mesoscale eddy signatures in surface mixed-layer depth (MLD) is provided across the Southern Ocean (SO). Eddy composite MLD anomalies ...
Investigating the role of trichodesmium spp. in the oceanic nitrogen cycle through observations and models Olson, Elise M. B. (Massachusetts Institute of Technology and Woods Hole Oceanographic Institution, 2014-06)The nitrogen fixation and abundance of Trichodesmium colonies and their connections with physical processes were investigated through Video Plankton Recorder (VPR) and other observations collected in fall 2010 and spring ...