Low-Frequency Variability of Temperature in the Vicinity of the Equatorial Pacific Thermocline in SODA: Role of Equatorial Wave Dynamics and ENSO Asymmetry
type: Dataset
contact point: Organization
  fn: CCSD
keyword: coupled-model
keyword: infoeu-reposemanticsarticle
keyword: south-pacific
keyword: tropical-pacific
keyword: ocean
keyword: el-nino
keyword: modulation
keyword: journal-articles
keyword: ogcm-simulation
keyword: decadal-variability
keyword: sduoceansciences-of-the-universe-physicsocean-atmosphere
keyword: amplitude
keyword: interannual-variability
landing page: 0894-8755
description: The Simple Ocean Data Assimilation (SODA) reanalysis (1958-2001) is used to investigate the decadal variability in the equatorial thermocline in the Pacific. Whereas the thermocline depth exhibits weak variation at decadal time scales, the temperature change in the vicinity of the thermocline in the western Pacific is significant and has a vertical scale of; 150 m. Based on a modal decomposition of the model variability, it is shown that such temperature change can be interpreted to a large extent as vertical displacements of the isotherms associated with the Kelvin and first meridional Rossby waves of the first three baroclinic modes. This indicates that decadal change at the subsurface in the warm pool region may be forced by the winds, consistent with the results of a multimode linear model simulation. The decadal mode of vertical temperature can be described by the first two dominant statistical modes (EOFs): the first mode is associated with changes in the slope of the thermocline (swallowing in the western-central Pacific and deepening in the eastern Pacific), representative of the 1976/77 climate shift and ahead of the ENSO modulation; and the second mode corresponds to a basinwide uplift of the thermocline and behind the ENSO modulation. It is further shown that the subsurface temperature in the warm pool region is negatively skewed, which results from the ENSO asymmetry. The results are consistent with the hypothesis of change in mean state resulting from the residual effect of the asymmetric ENSO variability.
issued: 2026-05-05T10:39:08.442593
language: en
modified: 2026-05-05T10:39:08.442597

test_moissonnage_selune
type: Agent

Low-Frequency Variability of Temperature in the Vicinity of the Equatorial Pacific Thermocline in SODA: Role of Equatorial Wave Dynamics and ENSO Asymmetry
type: Distribution
access URL: https://hal.science/hal-00994267
format: HTML
issued: 2026-05-05T10:39:08.448594
modified: 2026-05-05T10:39:08.428881