The Origin, Pathway, and Destination of Niño-3 Water Estimated by a Simulated Passive Tracer and Its Adjoint

Fukumori, Ichiro; Tong Lee; Cheng, Benny; Menemenlis, Dimitris
March 2004
Journal of Physical Oceanography;Mar2004, Vol. 34 Issue 3, p582
Academic Journal
The nature of subtropical–tropical water mass exchange in the Pacific Ocean is investigated, focusing on the origin, pathway, and destination of water occupying the surface layer of the eastern equatorial Pacific Ocean (Niño-3 region; 5°S–5°N, 150°–90°W). Simulated passive tracers and their adjoint are employed to explicitly follow the circulation of specific water masses accounting for advective and diffusive effects and their time variabilities. The evolution of the forward passive tracer and adjoint passive tracer can be identified as describing where the tracer-tagged water mass goes and from where it comes, respectively. Over 10 years on average, water mass of the Niño-3 region can be traced back to eastern subtropical thermocline waters of the Northern (27%) and Southern Hemispheres (39%). The Niño-3 water subsequently returns to these subtropical latitudes in the upper ocean. In contrast to the hypothesized “subtropical cell,” however, this circulation is an open circuit with water returning to the western regions of the two hemispheres (subtropical gyres) and to the Indian Ocean, instead of returning to its origins. The representative transit time scale from the subtropics to the Tropics is 10–15 yr. Temporal variability causes the tropical circulation inferred from a time-mean state to differ significantly from the average circulation. In particular, stirring due to nonseasonal, intra-annual variability significantly enhances the transport magnitude of the so-called interior pathways relative to that of the circuitous low-latitude western boundary pathways. Such short-circuit in the subtropical–tropical exchange may help better to explain tracer distributions, such as the observed midbasin tritium maximum in the equatorial Pacific Ocean. Significant differences in circulation pathways are also identified that are associated with El Niño and La Niña events. The strength of the subtropical–tropical water mass exchange is estimated to have weakened during the 1990s.


Related Articles

  • SEA WATER TEMPERATURE REGIME IN THE ROMANIAN BLACK SEA COAST AREA. Bostina, Alina Lucia // Analele Universitatii Maritime Constanta;2010, Vol. 11 Issue 13, p21 

    The thermal analysis of marine waters in the Black Sea coastal area refers to the multi-annual average temperature values, maximum and minimum, both vertically and by comparing the area of shore and offshore waters. Aspects of daily and seasonal variations of seawater temperature are detected by...

  • Eddy-Resolving Model Estimate of the Cabbeling Effect on the Water Mass Transformation in the Southern Ocean. Urakawa, L. Shogo; Hasumi, Hiroyasu // Journal of Physical Oceanography;Aug2012, Vol. 42 Issue 8, p1288 

    Cabbeling effect on the water mass transformation in the Southern Ocean is investigated with the use of an eddy-resolving Southern Ocean model. A significant amount of water is densified by cabbeling: water mass transformation rates are about 4 Sv (1 Sv ≡ 106 m3 s−1) for...

  • Simulating the Southwestern Indian Ocean's Seychelles Dome.  // CO2 Science;5/29/2013, Vol. 16 Issue 22, p5 

    The article reports on the result of a study which evaluated model biases associated with the Scychelles Dome in southwestern Indian Ocean. The findings reveal that most models erroneously produce an upwelling dome in the eastern half of the basin and that easterly biases are prominent along the...

  • DINEOF reconstruction of clouded images including error maps. Application to the Sea-Surface Temperature around Corsican Island. Beckers, J.-M.; Barth, A.; Alvera-Azcárate, A. // Ocean Science Discussions;2006, Vol. 3 Issue 4, p735 

    We present an extension to the Data INterpolating Empirical Orthogonal Functions (DINEOF) which allows not only to fill in clouded images but also to provide an estimation of the error covariance of the reconstruction. This additional information is obtained by an analogy with optimal...

  • Upwelling characteristics derived from satellite sea surface temperature data in the Gulf of Finland, Baltic Sea. Uiboupin, Rivo; Laanemets, Jaan // Boreal Environment Research;2009, Vol. 14 Issue 2, p297 

    The seven-year (2000-2006) satellite sea surface temperature (SST) data were examined to determine characteristics of coastal upwellings during the warm period of the year (June-September) in the Gulf of Finland. A total of 20 sufficiently cloud-free SST images depicting well-expressed coastal...

  • The Relationship between Sea Surface Temperature and Thermocline Depth in the Eastern Equatorial Pacific. Hein Zelle, J.A.; Appeldoorn, Gerrian; Burgers, Gerrit; van Oldenborgh, Geert Jan // Journal of Physical Oceanography;Mar2004, Vol. 34 Issue 3, p643 

    The time dependence of the local relation between sea surface temperature (SST) and thermocline depth in the central and eastern equatorial Pacific Ocean is analyzed for the period 1990–99, using subsurface temperature measurements from the Tropical Atmosphere–Ocean Array/Triangle...

  • SST Assimilation Experiments in a Tropical Pacific Ocean Model. Youmin Tang; Kleeman, Richard; Moore, Andrew M. // Journal of Physical Oceanography;Mar2004, Vol. 34 Issue 3, p623 

    With a simple 3DVar assimilation algorithm, a new scheme of assimilating sea surface temperature (SST) observations is proposed in this paper. In this new scheme, the linear relation between any two neighboring depths was derived using singular value decomposition technique and then was applied...

  • Editorial: Late Holocene oceanographic and climate change from the western European margin: the results of the HOLSMEER project. Scourse, James; Sejrup, Hans Petter; Jones, Phil D. // Holocene;Nov2006, Vol. 16 Issue 7, p931 

    The underlying aim of the HOLSMEER project has been to improve our understanding of natural climate variability through the search for, interpretation and quantification of, climatic variability in very high-resolution shallow marine records from Atlantic Europe covering the last 2000 years....

  • Air-Sea Interaction over the Eastern Pacific Warm Pool: Gap Winds, Thermocline Dome, and Atmospheric Convection. Shang-Ping Xie; Haiming Xu; Kessler, William S.; Nonaka, Masami // Journal of Climate;Jan2005, Vol. 18 Issue 1, p5 

    High-resolution satellite observations are used to investigate air-sea interaction over the eastern Pacific warm pool. In winter, strong wind jets develop over the Gulfs of Tehuantepec, Papagayo, and Panama, accelerated by the pressure gradients between the Atlantic and Pacific across narrow...


Read the Article


Sorry, but this item is not currently available from your library.

Try another library?
Sign out of this library

Other Topics