Thermal Expansion-Induced Sea Level Increase Determined by Flexible Global Ocean–Atmosphere–Land System Model

Abstract

To reveal the thermal expansion-induced sea level increase determined by the Flexible Global Ocean–Atmosphere–Land System Model (FGOALS), two versions of the model are used to conduct twentieth century historical climate simulation and future climate change projection under scenario RCP8.5 of the Intergovernmental Panel on Climate Change (IPCC). Both models reasonably reproduce mean dynamic sea level features with a spatial pattern correlation coefficient of 0.97 with the observation. Under the RCP8.5 scenario, global-averaged steric sea level exhibits a pronounced rising trend throughout the twenty first century with a significantly larger magnitude of changes over that in the twentieth century. By the year 2100, the global-averaged steric sea level anomaly is 18 and 10 cm relative to the year 1850 in version 2 of the FGOALS spectral and grid-point models, FGOALS-s2 and FGOALS-g2, respectively. In addition, the separate contributions of thermosteric and halosteric components are evaluated. In the twentieth century, the steric sea level changes in FGOALS-s2 (FGOALS-g2) are largely attributed to the thermosteric (halosteric) component relative to the pre-industrial control run. In contrast, in the twenty first century, the thermosteric component dominates the steric sea level change in both models under the RCP8.5 scenario.