Semi-Empirical Modeling of Spatial Variations in Sea Level Rise

Sea level rise is one of the important impacts of climate change. Accordingly, the projection of future sea-level has drawn a lot of attentions. The consensus is that the models based on physical processes may not yet predict sea-level changes with confidence. An alternative way to model global sea level rise is the empirical or semi-empirical approaches recommended in the literature. In this study, we extended the empirical model concept to incorporate spatial resolution to characterize spatial variations of sea-level rise and to investigate interactions among sea-level and sea surface temperature (SST) in different regions of the world's oceans. In our model, the world's oceans are divided into 4 regions, and both rate of sea level rise and rate of temperature change for each region are proposed to be linearly correlated with sea-level and sea surface temperature of the 4 regions. This empirical model is calibrated using published spatial sea-level data and sea surface temperature records from 1950 to 2001, and the model fit matches historical records well. Based on the calibrated parameters, both sea level and temperature of Gulf of Mexico have relatively different characteristics from those of the other 3 regions. The calibrated model indicated that sea-levels of the four regions all rise significantly in the 21st century but not at the same level. The proposed model is an alternative to existing studies in the literature.