Observing ocean heat content using satellite gravity and altimetry
Abstract
A method for combining satellite altimetry observations with satellite measurements of the Earth's time-varying gravity to give improved estimates of the ocean's heat storage is presented. Over the ocean the time-variable component of the geoid can be related to the time-varying bottom pressure. The methodology of estimating the ocean's time-varying heat storage using altimetric observations alone is modified to include observations of bottom pressure. A detailed error analysis of the methodology is undertaken. It is found that the inclusion of bottom pressure improves the ocean heat storage estimates. The improvement comes from a better estimation of the steric sea surface height by the inclusion of bottom pressure in the calculation, over using the altimeter-observed sea surface height alone. On timescales of the annual cycle and shorter the method works particularly well. However, long-timescale changes in the heat storage are poorly reproduced because of deficiencies in the methodology and the presence of contaminating signals in the bottom pressure observations.
- Publication:
-
Journal of Geophysical Research (Oceans)
- Pub Date:
- February 2003
- DOI:
- 10.1029/2002JC001619
- Bibcode:
- 2003JGRC..108.3031J
- Keywords:
-
- Geodesy and Gravity: Planetary geodesy and gravity (5420;
- 5714;
- 6019);
- Oceanography: Physical: Sea level variations;
- Geodesy and Gravity: Ocean/Earth/atmosphere interactions (3339);
- Geodesy and Gravity: Space geodetic surveys;
- Oceanography: General: Remote sensing and electromagnetic processes (0689);
- ocean heat content;
- altimetry;
- satellite gravity;
- steric height;
- remote sensing