Assessment of Altimetric Range and Geophysical Corrections and Mean Sea Surface Models—Impacts on Sea Level Variability around the Indonesian Seas

Eko Handoko,Clara Lázaro,Maria Fernandes

doi:10.3390/rs9020102

Eko Handoko, Clara Lázaro + Show 1 more

Open Access

https://doi.org/10.3390/rs9020102

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Abstract

The focus of this study is the assessment of the main range and geophysical corrections needed to derive accurate sea level time series from satellite altimetry in the Indonesia seas, the ultimate aim being the determination of sea level trend for this region. Due to its island nature, this is an area of large complexity for altimetric studies, a true laboratory for coastal altimetry. For this reason, the selection of the best corrections for sea level anomaly estimation from satellite altimetry is of particular relevance in the Indonesian seas. The same happens with the mean sea surface adopted in the sea level anomaly computation due to the large gradients of the mean sea surface in this part of the ocean. This study has been performed using altimetric data from the three reference missions, TOPEX/Poseidon, Jason-1 and Jason-2, extracted from the Radar Altimeter Database System. Analyses of sea level anomaly variance differences, function of distance from the coast and at altimeter crossovers were used to assess the quality of the various corrections and mean sea surface models. The selected set of corrections and mean sea surface have been used to estimate the sea level anomaly time series. The rate of sea level rise for the Indonesian seas was found to be 4.2 ± 0.2 mm/year over the 23-year period (1993–2015).

Highlights

As a consequence of climate change, sea level rise can be a serious problem for inhabitants of coastal regions
The Sea level anomaly (SLA) estimated from various corrections (dry troposphere, wet troposphere, ionosphere, sea state bias, tides) and mean sea surface models, were compared
The path of the radar altimetry signal through the atmosphere is delayed by the presence of neutral gasses in the troposphere

Summary

Introduction

As a consequence of climate change, sea level rise can be a serious problem for inhabitants of coastal regions. Sea level rise may cause inundation of low-lying areas, flooding, and salt seawater intrusion into surface water and aquifers [1]. These effects have a significant impact on national socio-economics, infrastructure and environment due to land-loss around coastal areas, where more than 10% of the world’s population lives [2]. Since the end of the 19th century, tide gauges have been installed to record sea level variability along coastlines and islands, in a limited amount and distribution in some regions of the world. Tide gauge measurements have some limitations due to their density of distribution, local impacts and are affected by vertical land movements such as land subsidence [5,6]

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