Sea Level Variation around Australia and Its Relation to Climate Indices

Abstract

This study aims at investigating the intradecadal and decadal signals of the sea level using 25 years of altimetry data around Australia. We have used the multivariable spectral analysis to extract six periodic signals at the 95% confidence level from altimetry-derived sea-level time series in the study area. They are signals with periods of 1, 1.5, 3, 4.3, 5.7 and 11.17 years, which can also be detected in the estimated power spectra from climate indices of the Interdecadal Pacific Oscillation, Multivariate ENSO Index, and Pacific Decadal Oscillation. A parametric model including the detected periodic signals is used to estimate sea-level trends. The determined trends in the area are in a good agreement with recent studies that consider effects of climate indices through a multivariate regression model. The advantage of our model is to present more descriptive explanation of the sea level signals around Australia in terms of periodicity and spatial variability.

Keywords:

• Australia
• climate indices
• regional sea level change
• satellite altimetry
• sea level spectral analysis

Acknowledgements

We would like to acknowledge the RADS data team to provide us with good quality altimetry data. We acknowledge Professor John Church for the valuable discussion while we had at the beginning of this study. We are also grateful for the anonymous reviewers and editors who evaluate this manuscript.

Additional information

Funding

The first author is supported by the University of Newcastle Postgraduate Research Scholarship and International Tuition Fees Scholarship for his PhD study.