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

Author: Christopher Piecuch, Katherine J. Quinn and Rui M. Ponte
June 19, 2013
Journal Article
Geophysical Research Letters

Knowledge of the relationship between bottom pressure pb and sea level ζ 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 ζ and pb over long periods (>1 year) and large scales (>750 km). Elevated pb 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 ζ variance is explained by pb variance. Correlation between ζ and pb 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 ζ variability cannot always be interpreted in terms of steric changes alone.

Geophysical Research Letters: Volume 40, Issue 12, pages 3106–3110, 28 June 2013.
DOI: 10.1002/grl.50549.

This article was also highlighted as a featured article on GRL's home page as the “First Look at Interannual Regional OBP Variations from GRACE Release-05”.  This is the first observation-based investigation of the relationship between ocean bottom pressure and sea level over the global ocean on interannual time scales.

Key Points

  • We give first look at interannual regional OBP variations from GRACE Release-05
  • OBP explains much of SL variance in extratropical basins and semi-enclosed seas