Reconstruction of local sea levels at South West Pacific Islands - a multiple linear regression approach (1988–2014)

Kumar, V. and Melet, A. and Meyssignac, B. and Ganachaud, A. and Kessler, W.S. and Singh, Awnesh M. and Aucan, J. (2018) Reconstruction of local sea levels at South West Pacific Islands - a multiple linear regression approach (1988–2014). Journal of Geophysical Research: Oceans, 123 . pp. 1502-1518. ISSN 2156-2202

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Abstract

Rising sea levels are a critical concern in small island nations. The problem is especially serious
in the western south Pacific, where the total sea level rise over the last 60 years has been up to 3 times the
global average. In this study, we aim at reconstructing sea levels at selected sites in the region (Suva,
Lautoka—Fiji, and Noumea—New Caledonia) as a multilinear regression (MLR) of atmospheric and oceanic variables. We focus on sea level variability at interannual-to interdecadal time scales, and trend over the
1988–2014 period. Local sea levels are first expressed as a sum of steric and mass changes. Then a dynamical
approach is used based on wind stress curl as a proxy for the thermosteric component, as wind stress curl anomalies can modulate the thermocline depth and resultant sea levels via Rossby wave propagation.
Statistically significant predictors among wind stress curl, halosteric sea level, zonal/meridional wind stress
components, and sea surface temperature are used to construct a MLR model simulating local sea levels.
Although we are focusing on the local scale, the global mean sea level needs to be adjusted for. Our reconstructions provide insights on key drivers of sea level variability at the selected sites, showing that while local dynamics and the global signal modulate sea level to a given extent, most of the variance is driven by regional factors. On average, the MLR model is able to reproduce 82% of the variance in island sea level,
and could be used to derive local sea level projections via downscaling of climate models.

Item Type:	Journal Article
Additional Information:	JGR - OCEANS
Subjects:	G Geography. Anthropology. Recreation > GC Oceanography G Geography. Anthropology. Recreation > GE Environmental Sciences Q Science > Q Science (General) Q Science > QC Physics
Divisions:	Pacific Centre for Environment and Sustainable Development (PACE-SD)
Depositing User:	Awnesh Singh
Date Deposited:	22 May 2018 00:26
Last Modified:	17 Jun 2018 22:51
URI:	https://repository.usp.ac.fj/id/eprint/10626

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