Work

Salinity Contribution to Regional Sea Level Trends in the Tropical Southwestern Pacific Ocean Over 2014–2023

Year: 2025

Type: article

Abstract: Steric sea‐level has been identified as the main driver of regional sea‐level trends. Altimetry‐based spatial patterns vary as a function of space and time. Thermosteric (temperature‐related) sea‐level trends have generally been found to be more important than the halosteric (salinity‐related) trends. Using satellite altimetry data together with an Argo‐based gridded product, we find a negative trend in halosteric sea‐level in the Tropical Southwestern Pacific Ocean over 2014–2023, which attenuates thermosteric sea‐level trends during this period. This striking negative halosteric trend is associated with salinization of the upper 400 m, which is related to both salinity anomalies on isopycnal surfaces and to the vertical movement of isopycnals. This salinization can be explained by a precipitation deficit and by a remote contribution from wind‐driven wave propagation. Our results highlight the importance of salinity changes when interpreting satellite altimetry data.

Source: Geophysical Research Letters

DOI: 10.1029/2025gl116115

Authors: William Llovel, Antoine Hochet

Institutions: Centre National de la Recherche Scientifique, Ifremer, Laboratory for Ocean Physics and Satellite Remote Sensing, Institut Universitaire Européen de la Mer, Institut de Recherche pour le Développement

Language: English

Topic: Oceanographic and Atmospheric Processes

Subfield: Oceanography

Field: Earth and Planetary Sciences

Domain: Physical Sciences

SDGs: Climate action, Life below water

Open Access status: gold

Estimated APC paid: $3,190