Long-term trends, interannual variability and seasonal patterns of mean sea level in the Canary Islands

Abstract

This study analyzes mean sea level variability in the Canary Islands from 1993 to 2022 using tide gauge and satellite altimetry data. During this period, both Las Palmas de Gran Canaria and Santa Cruz de Tenerife exhibited a significant sea level rise of 4.04 ± 0.83 and 4.38 ± 0.93 mm yr−1, respectively. Comparison between tide gauge and altimetry records reveals slight land subsidence at both locations, approximately 0.5–0.7 ± 0.55 mm yr−1, contributing to the observed relative sea level rise. The spatial differences in the trends observed from altimetry appear to be associated with mesoscale ocean dynamics, particularly an increase in eddy activity along the Canary Eddy Corridor. Projections based on IPCC SSP scenarios suggest that sea level could rise by up to 395 mm in Santa Cruz and 365 mm in Las Palmas by 2050 under high-emission conditions. An additional 20 mm could be added due to land subsidence if it remains constant. Interannual variability is primarily correlated with the North Atlantic Oscillation (NAO); however, Atlantic Multidecadal Oscillation (AMO) and the Atlantic Meridional Overturning Circulation (AMOC) indices also appear to correlate well with its low-frequency components. The seasonal cycle, driven primarily by steric effects, peaks in late summer and reaches a minimum in late winter, with its amplitude varying across the region. The seasonal amplitude is approximately 49.6 mm in Las Palmas and 70.2 mm in Santa Cruz.