Comparing the steric height in the northern Atlantic with satellite altimetry

Anomalies of dynamic height derived from ananalysis of Argo profiling buoys data are analysed to assessthe relative roles of contributions from temperature and salinityover the North Atlantic for the period of 1999–2004. Theyare compared with dynamic topography anomalies based onTOPEX/Poseidon and Jason altimetry. It is shown that thehalosteric contribution to the anomalies of dynamic heightis comparable in magnitude to the thermosteric one overthe period analyzed. Taking both salinity and temperatureinto account improves the agreement between zonally averagedtrends in the satellite dynamic topography and dynamicheight increasing the correlation between them to 0.73 from0.63 when only temperature variability is taken into account.The implication of this result is that the salinity contributioncannot be neglected in the North Atlantic and that one cannotrely on estimating the thermosteric part by anomalies in thesea surface dynamic topography derived from the satellite altimetry