Sea level rise quantification and projection using multi-mission satellite altimeter over Malaysian seas

Abstract

The increase of anthropogenic activities has triggered rising global sea levels and threatens many low-lying and unprotected coastal areas. Without countermeasures, global sea levels will continue to rise at an accelerating rate in the 21st century. Geographically, Malaysia is epitomized by its unique geographical settings and is surrounded by water, hence a comprehensive study of the seas is vital for local management to take significant measures to understand and protect Malaysian coastline from threatening disasters. This study makes a significant effort to quantify and project sea level trends for this region by taking into account regional sea temperature changes. It presents an approach to quantify sea level trends based on multi-mission satellite altimeters over Malaysian seas. Future projection of sea levels was performed for every 20 years from 2020 to 2100. Multi-mission satellite altimetry data for Sea Level Anomalies and Sea Surface Temperature was processed using the Radar Altimeter Database System. Radar Altimeter Database System performs enhanced processing strategies for the derivation of sea level anomalies, including filtering, gridding, and moving average. The daily solutions of this data were combined into monthly average solutions for sea level rise quantification and projection. The assessment results show similar sea level anomaly patterns of high correlation coefficients (>0.9) and small (few cm) Root mean square errors between sea level anomalies from altimetry and tide gauges over the same period. Subsequently, sea level trends were determined using robust fit regression analysis for the sea level anomaly time series, where the sea level rise trends around Malaysia ranged from 3.37 ± 0.13 mm yr-1 off Peninsular Malaysia to 5.00 ± 0.10 mm yr-1 off Sabah and Sarawak with an overall mean of 4.17 ± 0.16 mm yr-1. From 1993 to 2015, cumulative sea level rise was 4.86 cm. During the 21st century, Malaysian seas will encounter a rise of 6.07 cm by 2020, 13.15 cm by 2040, 20.23 cm by 2060, 27.31 cm by 2080, and 34.39 cm by 2100. Information on sea level changes in this region is valuable for a wide variety of climate applications and for studying environmental issues such as global warming in Malaysia. It is also important for its relevance to predicting future regional climates for disaster adaptation measures.