A sustained acceleration of global mean sea level rise over altimetry era

Sang-chul Cha, Jeju National University, Jeju City, South Korea, Jae-Hong Moon, Jeju National University, Korea, Republic of (South) and Joon Ho Lee, Jeju National Universty, South Korea
Global mean sea level (GMSL) is among the most important indicators of climate and environment changes. Since the early 1990s, GMSL rose at a mean rate of ~3.3mm/yr; however, the temporal evolution of the rate decreased during the hiatus period of 2000s, whereas the rate clearly accelerated after the end of the hiatus. The temporal changes of the GMSL rise may be due to internal climate variability, which serves to obscure the background anthropogenic trend. In this study, we first diagnose the sea level budget over the altimetry era (1993–2017) based on altimetry, steric sea-level, ice sheets, and terrestrial water storage data sets and then investigate how the rate of the GMSL rise changes over the recent decades using an ensemble empirical mode decomposition (EEMD). Our result shows a distinct decadal mode in the GMSL, which corresponds to a decreasing rate of the GMSL during the hiatus period and a recent acceleration of the rate after the hiatus. In addition, we find that when separating the decadal mode from the GMSL, the rate of the trend is steadily increasing from 1993 to the present.

This work was supported by the National Research Foundation of Korea (NRF) grant funded by the Korean government (MSIP) (NRF-2019R1A2C1003206).