Decadal Sea Level Variability in the South Pacific in a Global Eddy-Resolving Ocean Model Hindcast
Open Access
- 1 August 2008
- journal article
- Published by American Meteorological Society in Journal of Physical Oceanography
- Vol. 38 (8), 1731-1747
- https://doi.org/10.1175/2007jpo3915.1
Abstract
Sea level variability and related oceanic changes in the South Pacific from 1970 to 2003 are investigated using a hindcast simulation of an eddy-resolving ocean general circulation model (OGCM) for the Earth Simulator (OFES), along with sea level data from tide gauges since 1970 and a satellite altimeter since 1992. The first empirical orthogonal function mode of sea level anomalies (SLAs) of OFES exhibits broad positive SLAs over the central and western South Pacific. The corresponding principal component indicates roughly stable high, low, and high SLAs, separated by a rapid sea level fall in the late 1970s and sea level rise in the late 1990s, consistent with tide gauge and satellite observations. These decadal changes are accompanied by circulation changes of the subtropical gyre at 1000-m depth, and changes of upper-ocean zonal current and eddy activity around the Tasman Front. In general agreement with previous related studies, it is found that sea level variations in the Tasman Sea can be explained by propagation of long baroclinic Rossby waves forced by wind stress curl anomalies, if the impact of New Zealand is taken into account. The corresponding atmospheric variations are associated with decadal variability of El Niño–Southern Oscillation (ENSO). Thus, decadal sea level variability in the western and central South Pacific in the past three and half decades and decadal ENSO variability are likely to be connected. The sea level rise in the 1990s, which attracted much attention in relation to the global warming, is likely associated with the decadal cooling in the tropical Pacific.Keywords
This publication has 57 references indexed in Scilit:
- Wind‐driven and steric fluctuations of sea surface height in the southwest PacificGeophysical Research Letters, 2006
- The response of the Southern Annular Mode, the East Australian Current, and the southern mid‐latitude ocean circulation to global warmingGeophysical Research Letters, 2005
- Variability and forcing of the East Australian CurrentPublished by American Geophysical Union (AGU) ,2005
- Present‐day sea level change: Observations and causesReviews of Geophysics, 2004
- The Response of the Antarctic Oscillation to Increasing and Stabilized Atmospheric CO2Journal of Climate, 2003
- From Anchovies to Sardines and Back: Multidecadal Change in the Pacific OceanScience, 2003
- Global high‐resolution mapping of ocean circulation from TOPEX/Poseidon and ERS‐1 and ‐2Journal of Geophysical Research: Oceans, 2000
- Geographical Variability of the First Baroclinic Rossby Radius of DeformationJournal of Physical Oceanography, 1998
- A Numerical Study on the Influence of the Mid-Atlantic Ridge on Nonlinear First-Mode Baroclinic Rossby Waves Generated by Seasonal WindsJournal of Physical Oceanography, 1988
- Observations of the Tasman FrontJournal of Physical Oceanography, 1980