Eastern equatorial Pacific Ocean T‐S variations with El Niño

Temperature‐Salinity (T‐S) relationship variability in the pycnocline of the eastern equatorial Pacific Ocean (NINO3 region, 5°S–5°N, 150°W–90°W) over the last two decades is investigated using observational data and model simulation. A numerical model simulation using the MITgcm (Massachusetts Institute of Technology General Circulation Model) suggests that, during El Niño years, the water in the eastern equatorial Pacific Ocean becomes saltier (by 0.1 to 0.2) and warmer (by 0.5 to 1°C) on density surfaces within the pycnocline. This simulation is consistent with Conductivity‐Temperature‐Depth (CTD) data collected mostly during Tropical Atmosphere Ocean (TAO) mooring maintenance cruises.

[1]  Dimitris Menemenlis,et al.  The Origin, Pathway, and Destination of Niño-3 Water Estimated by a Simulated Passive Tracer and Its Adjoint , 2004 .

[2]  Dimitris Menemenlis,et al.  Effects of the Indonesian Throughflow on the Pacific and Indian Oceans , 2002 .

[3]  Victoria J. Coles,et al.  North Pacific Subtropical–Tropical Gyre Exchanges in the Thermocline: Simulations with Two Isopycnic OGCMs , 2001 .

[4]  Michael J. McPhaden,et al.  Observations of Warm Water Volume Changes in the Equatorial Pacific and Their Relationship to El Niño and La Niña , 2000 .

[5]  G. D. Rowe,et al.  Upper equatorial Pacific Ocean current and salinity variability during the 1996–1998 El Niño–La Niña cycle , 2000 .

[6]  L. Perelman,et al.  Hydrostatic, quasi‐hydrostatic, and nonhydrostatic ocean modeling , 1997 .

[7]  L. Perelman,et al.  A finite-volume, incompressible Navier Stokes model for studies of the ocean on parallel computers , 1997 .

[8]  W. Large,et al.  Oceanic vertical mixing: a review and a model with a nonlocal boundary layer parameterization , 1994 .

[9]  J. Toole,et al.  Eastern Pacific Ocean circulation near the onset of the 1982–1983 El Niño , 1986 .

[10]  Gregory C. Johnson,et al.  Direct measurements of upper ocean currents and water properties across the tropical Pacific during the 1990s , 2002 .

[11]  S. Levitus,et al.  Objective analyses of temperature and salinity for the world ocean on a 1/4° grid , 1997 .

[12]  P. Gent,et al.  Isopycnal mixing in ocean circulation models , 1990 .

[13]  R. Lukas.  The termination of the Equatorial Undercurrent in the eastern Pacific , 1986 .