The Eastern Mediterranean Sea mean sea level decadal slowdown: the effects of the water budget

The Mediterranean Sea, as a semi-enclosed basin, is particularly sensitive to climatic changes, making it a critical region for studying sea level variability. This study investigates the decadal variability of the Mean Sea Level (MSL) trend in the Mediterranean and its subregions over the past 30 years (1993-2022), using a combination of satellite altimetry, tide gauges, and reanalysis datasets.

Our findings reveal a slowdown in the overall Mediterranean MSL trend during the 2013-2022 decade compared to previous periods, highlighting significant regional differences. The Western Mediterranean exhibits an accelerating trend consistent with global sea level rise, while the Eastern Mediterranean has experienced a decadal slowdown, including the Adriatic and Aegean Seas, where negative trends are observed. This slowdown is attributed to the combined effects of changes in the water cycle and the balancing of thermal and haline steric components. Increased evaporation emerges as a key driver of the observed trend changes, surpassing contributions from precipitation, runoff, and strait transport.

These results underscore the significance of the Mediterranean's water budget in influencing sea level trends and highlight the complexity of interpreting decadal sea level changes. The findings suggest that continued monitoring and a better understanding of regional water budgets are crucial for refining future projections and developing effective climate adaptation strategies for the Mediterranean coastal areas.