Reliability of the steric and mass components of Mediterranean sea level as estimated from hydrographic gridded products

Abstract

The steric component of Mediterranean sea level as obtained from different hydrographic gridded products is compared for the last decades. The widely used MEDATLAS2, ENACT/ENSEMBLES, ISHIIV6.7, and ISHIIV6.12 databases show large discrepancies, mainly derived from the halosteric component. The validation of the mass component against gravimetry data suggests that ENACT is slightly more accurate than the other data sets. Concerning long-term trends, the thermosteric component computed down to the bottom for the period 1960-2000 ranges from -0.06 ± 0.12 to 0.09 ± 0.16 mm/yr. Halosteric trends are negative for all products, but the magnitude and spatial patterns provided by the four products are statistically inconsistent among them. This prevents giving consistent figures for the overall steric term and mass term. Conversely, the trend of the freshwater content of the Mediterranean basin can be estimated more accurately, ranging from 1.0 to 1.3 mm/yr for the period 1960-2000. © 2013. American Geophysical Union. All Rights Reserved.