Satellite-derived interannual ocean bottom pressure variability and its relation to sea level

Knowledge of the relationship between bottom pressure p(b) and sea level is important for understanding ocean circulation and climate. We use recent Gravity Recovery and Climate Experiment (GRACE) Release-05 data along with altimetry to investigate the relationship between and p(b) over long periods (>1 year) and large scales (>750 km). Elevated p(b) signals are observed over deep extratropical regions (e.g., Southern Ocean basins) and shallow or semi-enclosed areas (e.g., Indonesian and Nordic seas). In these places, considerable variance is explained by p(b) variance. Correlation between and p(b) is significant in many regions, including instances of significant negative correlation suggestive of active baroclinic processes. Results exemplify the good quality of GRACE Release-05 data and demonstrate that contemporary regional variability cannot always be interpreted in terms of steric changes alone.