Long-wavelength steric sea level and heat storage anomaly maps to 2000 m by combining Argo temperature and salinity profiles with satellite altimetry and gravimetry

Abstract

Argo profiles of temperature/salinity (T /S) at specific times and locations from January 2003 through December 2023 are mapped into monthly maps of steric sea level (SSL), thermosteric sea level (TSL), and Ocean Heat Content (OHC) anomalies at long wavelengths (> 1500 km) down to depths of 2000 m. The mapping uses a monthly satellite reference computed from the difference between satellite altimetry and gravimetry, so that in periods where there is not sufficient global Argo coverage (generally before 2007), the satellite estimate is used instead of a mean monthly climatology or zero, as other analysis centers use. Longwave mapping is done to reduce large errors introduced by poor sampling of mesoscale eddies by the Argo floats. We demonstrate that on global- and basin-scales, the longwave mapping does not substantially affect calculations of mean SSL, TSL, or OHC changes. Monthly standard error maps from the mapping are also provided. These maps are intended for users interested in understanding global- and basin-scale sea level budgets, as well as combining with deep ocean measurements to study ocean heat uptake. The complete dataset is available from https://doi.org/10.17632/dsjkkhvywr.1 (Chambers and Reinelt, 2025).